Product Review: The Viking Merlin ED 8 x 32.

The Merlin ED 8 x 32 by Viking Optical UK.

A work begun July 31 2020

Recently I put a Viking Optical Kestrel ED 8 x 42 through its paces, and reported very favourably regarding its optical and mechanical quality. But over the last few months I’ve been hankering after a high-quality, light weight birding binocular that offers good value for money but wouldn’t break the bank. My search brought me to consider the Merlin(after the raptor, not the mythical magician lol) ED 8 x 32 also offered by Viking Optical for reasons that I wish to highlight in this review. But my approach in this blog will be decidedly different to most other reviews in that I wish to assess its many optical and mechanical features in comparison to two other binoculars; a Celestron Trailseeker 8 x 32, which has many attributes in common with the Merlin, and a smaller, Leica Trinovid BCA 8 x 20, as an additional control in assessing optical and mechanical quality.

The Merlin Binocular at a Glance:

 

Specification: 8 x 32mm

Weight(with/without strap): 561g/518g

Dimensions: W/H: 12.9 x 12.3 cm

Optics: Double ED objective, full multi-coated, with phase and dielectrically coated roof prisms

Field of View: 7.8 angular degrees(137m@1000m)

Eye Relief: 15.6mm

Waterproof: Yes

Fogproof/Nitrogen purging: Yes

Focusing: Central

Warranty: 10 years( 5 years parts & labour, 5 years parts only)

Accessories: Quality padded & neck strap,padded nylon carry case, rain guard, tethered objective covers, lens cleaning cloth.

Retail Price: £239.00

 

A Brief Word on Packaging: The Viking Merlin, just like the Kestrel 8 x 42 previously tested, came with the same high-quality presentation box, with all the above accessories included. Very nice!

Calvin Jones’ binocular guide booklet( 2017 edition).

I recently acquired a small booklet(47 pages), entitled, Choosing Binoculars For Birdwatching and Wildlife, written by Calvin Jones, founder and chairman of Ireland’s Wildlife.  Calvin, a veteran birder and naturalist, is a native of Wales, but has put down roots in West Cork, in the south of Ireland, where he offers tours to wildlife enthusiasts and birders. As an expert commentator on binoculars, his booklet consists of concise information and largely impartial advice to the general public on choosing a good binocular for nature observation. I would recommend this booklet to anyone interested in making a binocular purchase, and in this blog I’ll be comparing his advice on a point by point basis, to the binoculars showcased in this review, but will also be including additional tests not covered or mentioned by Mr. Jones in his booklet.

Quote: “Choosing quality optics is about finding the right compromise between size, weight, optical performance, ergonomics, practicality, function and price” Page 7.

Comment: Couldn’t agree more! Jones narrows down his recommendations to two principal formats: 8 x 42 and 8 x 32. For me, 8 x 42 carries a bit too much weight, especially as I intend to use it for many hours in the field. Thus I settled on the 8 x 32 format which offers most of the performance of the larger glass, during normal daylight hours at least, only showing some drawbacks to the larger instrument during very low light conditions. However, since I don’t do much terrestrial glassing at dawn or dusk, the greater light gathering power of the 42mm format is not necessary for my purposes. It is also worth noting that the smaller 8 x 32 format is less expensive than its larger counterpart, which is always good news.

Quote: “Today you can get a good pair of binoculars for a relatively modest investment of around £100-150, and you’ll find some excellent instruments in the £250-400 price bracket that will serve you faithfully for decades of bird watching and wildlife observation.” Page 9

The Celestron Trailseeker(top) offers great performance for its modest price tag but the Viking Merlin goes that little bit further for not much more money.

Comment: Again, I couldn’t agree more! Jones is fully aware that the cost of including high tech optical features, previously only available on premium brands, is now standard on mid-priced binoculars. The same is true of mechanical quality as well, though not quite to the same extent. This is great news for the budget-conscious enthusiast. The Viking Merlin delivers wonderful performance for its modest price tag, but so does the less expensive Celestron Trailseeker( ~£145), which possesses all of the optical features of the Merlin bar its ED billing. Mechanically though, the Merlin is significantly better, with a smoother all-metal focus wheel and right eye dioptre ring( they are made of plastic on the Trailseeker), and better overall ergonomics.

Quote: “Unless you’re looking to use your binoculars for a particular specialist task, choose something in the 8x to 10x range for general bird watching and wildlife observation.”  Page 19

Comment: Agreed. But between 8x and 10x, I would generally opt for the former more often than not. The reasons are several fold: less shake at lower power, so affording steadier views, less compromised optical quality(at 10x you’ll be introducing 25 per cent more chromatic aberration, and commensurately greater off-axis Seidel aberrations, all other things being equal), the field of view will be also larger in general with the 8x model, which is beneficial for tracking your target and enjoying vistas, and of course, brighter images, owing to the larger exit pupils afforded by the lower power for a given aperture.

Quote: ” Here are a few optical features its worth looking out for when researching your new binoculars:

ED or HD lenses: Colour fringing can be an issue with standard binoculars, particularly when viewing high contrast subjects(light subjects against a dark background or vice versa). ED or HD glass reduces or eliminates colour fringing, improving the perceived sharpness, contrast and colour fidelity of the resulting image.” Page 23-24.

Comments: Here I must admit to being less in agreement with the author. Comparing the views through the Trailseeker and the Merlin (same field of view), I would agree that there is a slight but very subtle improvement in sharpness and image contrast in the latter instrument. The amount of chromatic aberration is so vanishingly small that it’s really only apparent when looking at dark objects against a very bright background sky and only if you look for it. I simply don’t accept that there are night and day differences at the low powers (both 8x) served up by these binoculars. Indeed, I believe the effect of ED glass is generally exaggerated in low power binoculars such as these by the majority of reviewers, and counts for little in the way of improved optical performance. I also read comments like “the colours are off” in non-ED binos, but I don’t understand that either. With trained, average eyes I feel this claim is an exaggeration of the truth. The differences are small at best!

Note added in proof: Jones adds this comment on page 26:

“Look out for HD or ED glass in the objective lens – but bear in mind that non-ED binoculars from premium manufacturers can, and often do, outperform ED optics from some other brands.”

Comment:

The superb Leica Trinovid BCA 8 x 20 sports excellent optical performance without ED glass that outperformed a quality ED pocket glass.

Too right. I have, and previously reported that, a very nice Leica Trinovid BCA 8 x 20, which doesn’t have ED glass elements, still delivered sharper and more contrasted images than a high-quality Zeiss Terra ED 8 x 25 binocular. So, don’t believe the hype!

To summarise: I would never base a purchase of a good quality binocular solely on its ED billing. While it’s certainly advantageous to have ED glass as part of a well designed optical system, a properly executed non-ED glass can provide wonderful results in all weathers.

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A Curious Aside: In one or two on-line birding sites I’ve visited I came across statements to the effect of ” for birding you need an ED binocular.”

Is that so?

May I ask a few questions?

How long has the hobby of birding been in existence? And for how many of those years were ED binoculars available? What did birders do before the days of ED; pack up and go home?

Aye right!

Thieving gayponaut propaganda…. methinks.

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Quote: “Always choose fully-multi-coated optics for wildlife observation and birding. If you’re buying roof prisms look for phase correction …..dielectric coatings are better and deliver a brighter image but tend to cost significantly more…..look for additional protective lens coatings that shield the external lens surfaces.” Page 30.

Comments: Both the Merlin and the Trailseeker are fully multi-coated, have phase corrected optics as well as dielectric prism coatings. In my tests at dusk I noted no significant difference in the brightness of the image between the Merlin and the Trailseeker, so, once again, the claim made by more than a few reviewers – but not Mr. Jones himself –  that ED glass delivers brighter images is not substantiated by my findings. Indeed, while the ED glass should focus the light slightly more tightly, it cannot make a big difference to the brightness of the image. At 8x why should it?

What Calvin Jones does not mention much about in his booklet is control of glare, which the coatings on the lenses and prisms as well as the type of binocular baffling employed will certainly contribute to. In my tests conducted during bright overcast conditions in late July, I found the Leica Trinovid to have much stronger veiling glare than either the Celestron Trailseeker or the Viking Merlin.This is attributed to the much more greatly recessed objective elements in the latter instruments compared with the fully exposed objective lenses on the Leica Trinovid. However, such glare can be all but removed by shielding using your hand held above the objectives or by using a broad-rimmed hat.

Both the Celestron Trailseeker( foreground) and the Viking Merlin have deeply recessed objectives which help to keep veiling glare at bay. Note the distinctly different colours of the anti-reflection coatings on both instruments. I judged the quality of the coatings to be slightly better on the Merlin.

Internal reflection is another important contributor to loss of contrast in a binocular image. This is easily assessed by directing an intense beam of light into the binocular and examining the images for evidence of internal reflections as well as any diffused light in the image. Well, as I indicated in other blogs, the Leica Trinovid has the best stray light control of any binocular I have tested. The coatings and baffles used by Leica effectively eliminate this annoying artefact.

To my great surprise (and relief), the Merlin proved fully the equal of the Leica in side by side tests. There was hardly any internal reflections at all – and very subdued at that – and showed no signs of contrast-robbing diffused light either. Indeed I scored both the Leica and the Merlin a 10 for this test. The Celestron Trailseeker did very well in the same tests but did show a little more in the way of internal reflections, reducing its score to maybe 8.5 on the same scale.

All three of these binoculars will provide excellent performance at night when looking at strongly illuminated cityscapes, a bright Moon and more besides.

Quote: “Adequate field of view is important, but a super-wide field isn’t really necessary..” Page 32

Comments: Strongly agree!  Many 8 x 32s try to push the envelope and deliver very wide fields, sometimes in excess of 8.0 angular degrees. But the wider the field, the more difficult it will be to control off axis aberrations, such as field curvature, pin-cushion distortion and astigmatism etc. Better to have a smaller field that displays better edge-to-edge sharpness than have a very wide field which blurs the image too much at the periphery. Both the Merlin and the Trailseeker deliver the same field of view of 137m@1000m (7.8 angular degrees) but I found the sweetspot (inside which the image remains really sharp and pleasant) in the Merlin to be slightly wider than in the Trailseeker, but none were in the same class as the superlative Leica, which displays clearly superior edge of field sharpness in the same tests conducted on a bright waxing gibbous Moon sinking low into the south-southwest sky on the evening of July 28 2020. However, it must be noted that the field of view of the Leica is noticeably smaller(6.5 angular degrees) than either of the 8 x 32s tested.

Quote: “Make sure the binoculars you buy are robust enough to stand up to the rigours of extended field use. Choose a lightweight but sturdy pair, with good balance and grip and always make sure they are fully waterproof and nitrogen or argon purged.” Page 39.

Comment: Mr. Jones makes a very valid point here. Fortunately, most mid-priced binoculars are very well built these days and are constructed of strong and lightweight materials; polycarbonate, and alloys of aluminium, titanium and/or magnesium. The Merlin is constructed from a polycarbonate substrate, the Trailseeker from a magnesium alloy, and aluminium, in the case of a Leica. Many binocular commentators suggest that the metal alloy bodies are more durable, but I don’t have, as yet, any evidence to corroborate that.

The Celestron Trailseeker tips the scales some 100g less than the Merlin, but while this should act in the Trailseeker’s favour, there are other issues to consider. In particular, ergonomics; how the instrument feels and works in your hands. The Merlin feels very solid and its shorter bridge than the Trailseeker means that I can get my fingers firmly wrapped around the barrels for a firmer grip while glassing. The hard rubber overcoat has excellent grip and doesn’t attract a lot of dust like other models, such as the Nikon Prostaff 8 x 30 I tried some months back. What’s more, I am confident it won’t feel off any time soon unlike the concerns I had with the sweet little Nikon binocular.

The solidly constructed twist-up eye cups on the Viking Merlin hold their  extended positions rigidly and reliably.

But let’s look at other things. Consider the eye cups on both the Trailseeker and the Merlin. Both are solidly made from soft rubber over metal and have a couple of click stops that stay rigidly in place and can accommodate different amounts of eye relief for spectacle wearers as well as for those, like yours truly, who observe without glasses. The quality is the same for both these 8 x 32s and hand-on-heart, I actually prefer the eye cups on the Trailseeker that little bit better. That said, the Merlin’s eye cups are strong and will hold up well, I suspect, even after years of use. One neat way to see if your binocular eye cups are up to scratch is to extend them outwards fully before turning the instrument upside down to see if they support the weight of the binocular. If they do, you’re in business. I’m delighted to say that both the Merlin and the Trailseeker pass this test with flying colours!

Does your binocular pass the eye cup test? The Merlin does!

Other ergonomic issues to consider in a good birding binocular is the quality of the focus wheel. The Merlin has a smoother and more responsive focuser than the Trailseeker, with zero play or backlash. In addition, from one extreme of focus to the other entails turning it just over one revolution. The Trailseeker, in comparison, requires one and a half revolutions to go from one end of its focus travel to the other. This means that keeping objects in focus with the Viking Merlin is easier to achieve, especially on moving targets like birds in flight etc. That said, the Trailseeker actually has the better depth of focus, that is, it keeps objects in clear vision over a greater distance.

The Viking Merlin has a silky smooth focus wheel which takes just over one full revolution to go from one extreme to the other.

Going Minimal

After I cut off the bits of the neck strap I won’t be needing, I take a lighted match to the ends and melt it for a few seconds to stop it from fraying at some later stage.

One thing that really gets on my wick when using a binocular is the various appendages that attend the instrument- the tethered rain guard and objective lens caps, an unwieldy strap with ‘dangly’ bits getting in the way. Although I fully concede that the objective caps and rain guard are absolutely essential in some situations, on the average dry day, they are quite unnecessary to have on the binocular. I can do without the objective caps most of the time, as even in rainy situations, the objectives hang downward and the deeply recessed objective lenses act as natural protection against rain and mist. The rain guard need not be tethered to the strap either, but simply carried in a pocket and whipped onto the eye cups when the heavens open. Also, I can’t stand having too much slack in the binocular strap, so I cut them back to size and heat the cut ends with a match to stop them fraying at some later stage.

The result is a much leaner machine, one I can just pick up and use at a moment’s notice. Removing all such appendages also cuts down on the weight of the binocular. Indeed, in its minimalist form, it tips the scales at just 561g, which is much easier on the neck muscles!

The minimalist Merlin 8 x 32 weighs in at just 561g.

Quote: “While few people will buy binoculars solely on the strength of the warranty, and hopefully you won’t need to avail of it, a manufacturer’s willingness to stand over their product is obviously a major plus” Page 41

Comments: I agree. This is a very important aspect of any binocular purchase. It is very re-assuring to know that the company you buy your binocular from will stand behind their product and repair or replace parts as and when necessary. The fact that Viking Optical are a real optics firm and not just a retailer, I get the added benefit of knowing that even if the instrument is no longer under warranty, I can send it down to their technicians who will give it their professional attention and fix any problem that might arise.

Notes from the field

Oh I do like to be beside the seaside…..with a good 8 x 32.

To be continued………………

 

De Fideli.

Product Review: Viking Optical Kestrel 8 x 42 Binocular.

The Viking Optical Kestrel 8 x 42 binocular.

A work begun July 1 2020

Preamble:

** New  Review 5 added below, as well as an expanded conclusion towards the end of the blog.

  Review 1

  Review 2

  Review 3

  Review 4

** Review 5

Specification: 8 x 42

Eye Relief: 17.2mm

Field of View: 8.1 angular degrees (142m@1000m)/

Measured at 8.0 degrees in field tests

ED glass: Yes

Body: High density Polycarbonate, textured rubberised overcoat.

Weight: 692g

Coatings: Fully Multi-Coated

Dielectric Phase Coating: Yes

Dimensions: 12cm x 12cm x 4.5cm

Nitrogen Purged: Yes

Waterproof: Yes (1.5m for 3 min)

Tripod Mountable: Yes

Accessories: Padded soft case, high quality lanyard, instruction sheet

Warranty: 10 years

Retail Price: £205 UK

 

The British optics firm, Charles Frank of Glasgow, has been selling and repairing optical instruments for nearly three and a half decades. In 2016, the firm moved south to Halesworth, Suffolk, where they changed their name to Viking Optical. Recently, the company launched an exciting range of affordable roof prism binoculars featuring a number of impressive optical features exhibited in their Kestrel, Merlin and Peregrine(all keen eyed raptors) binoculars. Three models are offered in 8 x 32, 8 x 42 and 10 x 42 configurations, and all feature fully multi-coated optics, dielectrically coated and phase corrected BAK 4 prisms and objectives containing ED glass elements in a fully waterproof housing. Although all these models are assembled in China, I reasoned that their acquired knowledge in repairing binoculars over many years would put them in a strong position to offer a quality experience, so I pulled the plug and decided to order up the 8 x 42 Kestrel model for optical testing and evaluation.

First Impressions

The package as received.

The binocular was ordered up from Amazon and the instrument arrived in the evening of the following day. I was immediately impressed with the packaging of the Kestrel. Instead of the regular colour-saturated cardboard box that usually attends many of the binoculars that have passed through these parts, I received a very fetching presentation box with the phrase “Extend Your Horizons” printed on top. After removing an outer slip case, the binocular and accessories were carefully packaged away inside.

The inner box containing the binocular and accessories features an inspiring outdoor scene.

The package contained the binocular inside its soft padded case, a high quality padded neck strap and one page instruction sheet with details of the warranty. The company states that the binocular went through several stages of testing before the instrument was finally packaged up for distribution. Both the ocular and objective lenses came with standard soft rubber caps which can be permanently affixed to the binocular. I was half expecting a lens cleaning cloth but none was provided.

The binocular has a very attractive appearance, with the optics housed inside a strong polycarbonate body overlaid by an anthracite-coloured, texturised rubber armouring. While I have used binoculars with magnesium alloy bodies before, I have not noticed any particular advantage of using metal bodies over their synthetic polymer counterparts, except perhaps to shave off some excess weight. But at 692g, this binocular is not exactly heavy. Indeed, surveying the market in 8 x 42 roof prism binoculars quickly reveals that the weight of the Kestrel falls into the median in the range for instruments of this specification.

The fetching anthracite colour of the binocular is beautifully complemented by the sky blue logo of the company and its ED billing inlaid on the top surface of the instrument. I’m not normally taken much aback by the cosmetic appearance of a binocular but I must admit to really liking the colour scheme of this instrument!

The Viking Kestrel has a rugged anthracite body with the company’s attractive sky blue logo inlaid on the bridge.

The binocular has a single centrally placed hinge that is reassuringly rigid. Once adjusted to get your particular interpupillary distance (IPD) right, it stays in place even when taken out of and placed back inside of its padded case.  Both the focus wheel and right eye dioptre are constructed from metal and coarsely stippled for maximum grip. The twist-up eye cups are of very high quality, rubber over metal that offer 3 positions. With a very generous eye relief of 17.5mm(measured), they afford very comfortable viewing for those who wear eye glasses and those who don’t. Most importantly, when clicked into place they hold their position very solidly, even after an undue amount of pressure is applied.

The underside of the body has two small thumb rests which allow your fingers to naturally gravitate towards when handling in the field. Overall, I found the Kestrel to be very ergonomically designed.

Details of the underside of the Viking Kestrel 8 x 42 binocular.

The focus wheel moves with what I would describe as slow-to-standard progression. There is a little bit of play in it which can sometimes result in over- or under- focusing, especially when imaging a fast moving object, but overall I felt it was perfectly adequate for most purposes one would use a binocular like this for. The wheel moves through 1.5 revolutions from its close focus to beyond infinity. Having a little extra focus travel beyond the infinity setting may not have any immediate advantages, but I’ve found that it is quite important when attempting to clean up the image at the periphery of the field. In other words, having a slightly longer focus travel can help alleviate some of the off-axis Seidel aberrations found on most any binocular image.

The objective lenses on the Kestrel have very nice and evenly applied anti-reflection coatings.

The attractive cyan coloured anti-reflection coatings on the Kestrel ED binocular.

What’s more, they are very deeply recessed – exceptionally so, I’d say. I measured them at a whopping 10mm – significantly deeper than any other binocular I have encountered. This affords exceptional protection against rain, and wind-borne dust and will also attenuate the build up of contrast-robbing dew.

The objectives of the Kestrel are recessed a whopping 10mm or so, helping to keep airborne dust, spray and dew at bay during field use.

All in all, I was well pleased with the ergonomics and physical presentation of the Kestrel, but all of that counts for nought if the optics are not up to scratch.

Mounting the binocular on a tripod is easy to do by unscrewing the stalk at the front end of the bridge, between the two barrels,and which enabled me to test the collimation of the instrument by observing well defined targets on a hillside a few miles distant, looking for both horizontal and vertical asymmetries in the images presented in both optical tube assemblies. To my relief, the Kestrel showed no misalignment issues.

Stray light tests

No roof prism binocular, no matter how well made, can perfectly stave off unwanted reflections, diffraction artifacts and diffused light when a very strong light source is directed inside the instrument Setting up my standard iphone torch light test, I was very impressed with the results I obtained with the Kestrel. I used two controls to compare the views with this instrument; my trusty Barr & Stroud Savannah(which exhibits excellent stray light control and very subdued diffraction spikes) and my superlative Leica Trinovid BCA 8 x 20 pocket glass, which, until now, offered the best results I have recorded in such tests.  Well, the Kestrel served up an exceptionally clean image, with very low unwanted reflections and an almost imperceptible diffraction spike. The result bested the Barr & Stroud binocular and was the equal of the Leica but with a far less obvious diffraction spike! Furthermore, just like my two binocular controls, diffused light was pretty much non existent.

Stray light control instruments: the Viking Kestrel (bottom) with the Barr & Stroud Savannah (top).

Further testing on a sodium street light confirmed the same results; the view through the Kestrel had well nigh perfect results with no annoying internal reflections, zero diffused light and no diffraction spikes! I did however detect rather strong off-axis flaring with the Kestrel, which was more pronounced than in the control binoculars, as evidenced by placing the street light just outside the field stop of the instrument.

The Viking Kestrel (top) tested against the Leica Trinovid BCA (bottom).

Overall, I was very pleased with the outcome of these stray light tests, which suggested that the Kestrel would likely deliver exceptionally punchy images, rich in contrast during normal daylight use.

Daytime testing

My first day of testing took place on an overcast June day. Examining some tree trunks a few tens of yards distant showed a very wide and wonderfully sharp and vibrant image. Compared with my Barr & Stroud Savannah 8 x 42, the colour tone was noticeably more neutral in the Kestrel compared with the very warm yellowish tones in the former. Within its large sweet spot, I judged the image sharpness to be a tad better in the Kestrel than in the Barr & Stroud. Examining the summit of a nearby hill against a bright overcast sky also revealed that the Kestrel was better corrected for chromatic aberration as judged by the absence of a very faint sliver of blue fringing at the boundary between the summit and the background sky. The achromatic Barr & Stroud did show that fringe in the same test.

That said, it soon became clear to me that the Kestrel was showing some lens flare in a portion of the image similar to what I had previously detected in my sodium street lamp test, reducing its contrast in comparison to my control binocular. This flaring could be removed by simply placing my hand over the objectives, blocking off some of the bright light from the sky above it. The flaring was also reduced by observing through an open or closed window under a roof but always reappeared once I re-emerged into the out of doors.

The flaring was only slight though and I suspect that most folk wouldn’t have even noticed it, but once you see it it’s very hard to ignore it, especially since the less expensive Barr & Stroud Savannah did not exhibit such behaviour. Examining the exit pupils showed up a significant amount of light leakage which you can see in the image below:

Some light leakage around the right exit pupil is apparent in this shot.

I decided that I would contact Viking Optical describing the problem I had encountered to see if they were willing to have a technician look at the binocular. So, I fired off an email to them, describing the problem as best I could, and within a few minutes they got back to me asking if I’d be willing to send them the instrument so that they could properly assess its performance. I agreed, so back went the binocular into its case and box for shipping down to Suffolk.

I will continue this review as soon as I receive word on its progress.

A Change of Heart

I spent the afternoon of July 2 2020 comparing and contrasting the views through my Leica Trinovid 8 x 20 with the Kestrel 8 x 42 as well as the Barr & Stroud in bright sunny conditions. I detected the same weak veiling glare in the Leica and the Barr & Stroud  as I did in the Kestrel. Indeed, truth be told, it was more severe in the Leica than in the Kestrel on the same test objects, which I think is caused by its complete lack of any recession of its objective lenses. It was however a little less intense on the Barr & Stroud, but in every case it could be eliminated by shading the objectives with my hand. So I reached the conclusion that it is I who was really at fault. I have come to expect too much and have learned to spot tiny imperfections in optical performance. Furthermore, those light leaks around the Kestrel exit pupil lie outside of where my eyes intercept the image, and so will have little or no effect on the performance of the binocular.

Absolute perfection just cannot be obtained no matter how well made the binocular is. I therefore decided not to bother Viking with my petty complaint and will email them tomorrow morning informing them that I do not wish to pursue this matter, as well as to congratulate them on designing an excellent glass at such a good retail price.

Methinks a large slice of humble pie for tea is in order!

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An Aside: Veiling glare reported in the Leica Trinovid 8 x 20 binocular

A very bad case of glare in a Swarovski CL Companion 10 x 30

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Tests on Light Transmission

As I described in numerous previous blogs, the Barr & Stroud Savannah 8 x 42 is an excellent wide angle binocular, especially for its very modest retail price(£120UK), but I understand that it does not have the brightest dielectric coatings on the roof prisms( they may be either silver or aluminium). I therefore expected the Kestrel to deliver brighter images in low light conditions. So I ventured out at dusk on the overcast evening of July 1st 2020 and began comparing the views in both the Kestrel and the Savannah. Starting at about 10.15pm local time and ending at 10:40pm, I conducted simple A/B tests on some tree branches about 40 yards distant,  evaluating the brightness of the image in the binoculars as the light slowly drained from the landscape. These tests did show that the Kestrel served up the brighter images, as I would expect if they had better coatings, but the difference wasn’t exactly night and day. It was only a little bit brighter at best, becoming most apparent toward the end of the testing than at the beginning.

Investigating Claims that ED Glass Produces Brighter Images

I was also able to conduct more tests to ascertain if the presence of ED glass produces brighter images than an instrument with no ED glass. To make the test as fair as possible, I needed a binocular with good dielectric coatings but without ED glass. So, I borrowed my son’s Celestron Trailseeker 8 x 32 which I reviewed in an earlier blog. This binocular does have those all important dielectric coatings on the roof prisms and is also fully multi-coated like the Kestrel ED binocular. Because the apertures are different, I made an aperture stop of 32mm diameter from cardboard and placed it over one of the 42mm objectives on the Kestrel as shown below:

The cardboard aperture stop placed over the aperture of the 42mm objective of the Viking Kestrel(lower right). Note the Celestron Trailseeker binocular at the left of the image.

On the same evening of July 1, I compared the images served up with the stopped-down objective on the Kestrel with those garnered by the full-aperture Celestron Trailseeker 8 x 32, using the same eye to examine both. Again I performed these tests at dusk, when the test tree branches some 40 yard distant were in deep twilight. The results were quite revealing! Conducting the same A/B testing as before, I concluded that there was very little difference in their perceived brightness. I did however give the nod to the Kestrel though, but only just!

This is the second test of this nature that I have conducted, with both results seeming to indicate that ED glass either does not confer brighter images, or, if it does, it’s marginal at best.

This is at odds with bold claims made by many sources in the online literature and is widely adopted as a marketing stratagem to sell binoculars to the public.

Like I stated before, it’s not so much the ED elements as much as the coatings that distinguish an average binocular from a great one!

Further Notes on Glare, its Causes & its Management

Our long summer days here in Scotland are a godsend, not only because they allow one to observe for longer durations in warm or mild weather but, as I’ve been discovering, they afford many opportunities to conduct experiments with my binoculars. Today proved to be a good day to get to grips with the glare I’ve been observing with my instruments. The afternoon was very bright and sunny but as the afternoon gave way to evening, the skies became very overcast again, so I was able to test out two very different binoculars – the Leica Trinovid and the Viking Kestrel – in these very different conditions. I now believe I have a better understanding of what causes glare in these glasses, and so, by extension, in all binoculars.

The first observation I have made is that glare is actually a lot less problematic during sunny spells than it is during overcast spells. When the Sun is shining in a sky with little cloud cover, the main light source i.e.the Sun, is concentrated in one direction and so long as you are not looking at something very near the Sun, relatively little or no glare is noticed. For example, when glassing tree trunks located at the edge of a strongly shaded copse, with the afternoon Sun illuminating it from the side, glare is very well subdued in both binoculars. This kind of glare manifests itself as a localised crescent or arc at the bottom of the binocular image with much of the rest of the field being largely unaffected. The worst culprit is the little Leica Trinovid, as its objectives have no protection from stray ambient light. The Kestrel does significantly better under the same conditions because its objective lenses are located at the bottom of a 10mm deep ‘well’ which acts as a very effective lens hood, a trick long known to photographers.

But under overcast skies, where strong summer sunlight is diffused by extensive cloud cover, glare becomes much more of a problem in both instruments and seems to be more spread out in the binocular image. Glassing the same tree trunks at the edge of a shaded copse produces noticeably lower contrast images than under sunnier conditions; even when glassing near the Sun. The reason for this must be due to the fact that in the open air, under overcast conditions, with a bright sky overhead, there are many more locations where the light can reflect off the spacers between the objective lens elements at the bottom of the binocular objective, which in turn causes this flaring to spread out or diffuse across the binocular image, reducing contrast in a more noticeable way. This is referred to as veiling glare. So overcast skies appear to produce greater damage to the image because it has a greater potential to affect the entire field than much more localised crescent glare observed in clear sunny conditions. What is more, bigger glasses, which collect more light will show this type of glare well into twilight, whereas in smaller glasses which can’t collect as much light, the same glare can’t be seen!

Consulting a birding forum, I was able to verify this and I also learned that even alpha binoculars suffer from this problem. The poor chap was complaining about glare on his maiden voyage with his fancy new Zeiss Victory FL 8 x 42 and more knowledgeable glassers were able to chime in and offer some detailed explanations and a hefty dose of sympathy for good measure!

Three points to summarise all of this:

  1. The worst effects of glare can be removed by simply shielding the binocular objectives from the offending light source using your hand.
  2. Glare is a fact of life for most any glass, from the most humble to the most advanced. It’s par for the course and we must accept it and move on!
  3. Glassing under the canopy of a forest or in an observing booth with a roof over your head, or even donning a broad-rimmed hat will all but eliminate the worst effects of glare.

Further Notes on using the Viking Kestrel in the Field

Saturday July 3 2020

After a day of heavy rain, the clouds cleared off in the evening, leaving a tranquil blue sky. It was the perfect opportunity to go for a long walk around the picturesque Culcreuch Castle Estate with the Viking Kestrel 8 x 42. The instrument feels very solid in my hands and its fine mechanics work flawlessly. The quality padded neck strap with the company’s fetching colour logo proved very comfortable to use.  I stopped to say hello to a pair of Mute Swans and their family of five cygnets at Culcreuch Pond. The binocular served up beautiful, pin-sharp, views of the pure white plumage of the adults wonderfully contrasted with their rusty orange beaks and jet black foreheads. The cygnets had almost lost their fluffy down feathers by now and had developed their attractive tawny drapery, which stood out well against the sullen waters beneath them. And though the surface of the pond dappled in strong reflected sunlight, the binocular served up flawless images with incredible contrast and no annoying reflections.

Ambling up the path a little further, I enjoyed a fascinating fifteen minute excursion watching a group of Swallows perform their incredible feats of aeronautics (far more advanced than any human made flying machine) swooping and gliding with great speed and agility, gorging on low flying insects along a large grassy lawn immediately in front of the castle. The Kestrel proved to be a magnificent instrument to follow them, with its very large and well corrected field of view. Their prominent forked tails, iridescent blue-black upper body and almost comical, chocolate-brown faces could easily be made out as they flitted across the field of view. A lady out walking her dog, obviously curious about my glassing, stopped to tell me that a few big storms had threatened these migratory birds earlier in the year, reducing the numbers reaching our shores from Africa. It put a big smile on her face to see that it was business as usual for these noisy summer visitors!

These experiences convinced me that the Viking Kestrel 8 x 42 will make an excellent birding binocular with its superb contrast, sharpness and colour correction, not to mention its super-comfortable twist-up eye cups, generous exit pupil size and smooth focusing wheel.  As I continued to walk, I enjoyed glassing the intense colour of mature green leaves drenched with life-giving rains that made them glisten intensely in the early evening sunshine. I almost lost myself observing the intricately textured bark high up in their canopies against a gorgeous blue sky beyond. That said I must also report that there is very mild pincushion distortion at the edge of the field but certainly not enough to cause any alarm.

After sunset I ventured out again to catch a nearly full Moon skirting low in the south-southeast at about 11pm local time. To get a good unobstructed view I had to take a walk about half way up Culcreuch Castle Road. But it was worth it. The almost full Moon in all its glory hovered just above the tree line beyond a gently sloping hill, its low altitude imparting a yellowish cast to its normal pale silver countenance. The image served up in the Kestrel was gorgeous, pin-sharp across almost the entire field, with beautiful contrast and nary a sign of any internal reflections. This will make an awesome Moon glass! As usual, I noted that the Moon remained sharper when glassed horizontally than vertically; again very normal behaviour for a binocular.

Round about a quarter to local midnight, the sky had gotten sufficiently dark to make out the familiar asterism of the Plough high in the northwest. This afforded a perfect opportunity to estimate the size of the field of view. Well, I was able to hold Phecda and Merak in the same binocular field, which I estimated to be 7.9 angular degrees apart, with a tiny sliver of open sky available before it reached the field stop. Thus, I was confident that the ~8.0 degree field I measured was close enough to the quoted 8.1 figure stated in its official specifications. What is more, I glassed the bright orange star, Arcturus, high in the west-southwest, carefully examining the sharpness of the stellar image as it moved from the centre of the field all the way to the field stop. The results were good here too; Arcturus remained nice and pin sharp across most of the field with only the outer 10 per cent showing significant distortion, but there was no ballooning of the star like some inferior models I’ve glassed with in the past. That said, I was still able to play with the focus a little to tidy the image up somewhat at the edge of the field. All in all, I came away convinced that this would make an excellent star gazing glass. I can’t wait to use it later in the summer when truly dark stars return to our shores.

A most impressive performer.

Conclusions

There are good reasons why the 8 x 42 configuration is considered the darling glass for birders, hunters and general nature observers. The extreme comfort with which it meets with your eyes, moderate weight and great low light performance are just a few reasons why they have proven so popular. The Viking Kestrel 8 x 42 is packed full of hi-tech optical features and has very solid mechanics that will ensure it will serve you well for many years. The quality of the image is so good that it will rival those served up by models costing many times more. Indeed, if you’re saving up for a premium glass, I would strongly recommend you try this model first.  It could well be all the binocular you really need!

As you can see from reading the string of reviews posted at the beginning of this blog, the testers were pretty much unanimous in their praise of this extraordinary binocular, and for a retail price of just over £200 UK, I feel it represents exceptional value for money. Indeed, one reviewer thought that the Kestrels were the real winners from the entire Viking Optical range, especially when you consider bang for buck. What’s more, so far as I can tell, the more expensive Peregrine range (retailing for just over £300 UK) are distinguished from the Kestrel only in terms of weight and field of view. The Peregrine tips the scales at 600g, so shaving off about 15 per cent of the weight of the Kestrel, but it also has a smaller field of view (7.0 vs ~ 8.0 degrees). To many enthusiasts, these alterations will probably make little or no difference to their viewing enjoyment, so I would recommend you try the Kestrel before considering the Merlin or Peregrine models from the same company!

It really is a steal!

Viking Optical also has a solid reputation for repairing binoculars and this is yet another reason why it is an especially attractive option for British twitchers, in particular. If something should go wrong with your Viking binocular, you can be confident that their technical staff will repair it if it’s under warranty or, failing that, for a reasonable fee. And that’s very good to know!

The Viking Kestrel 8 x 42.

Highly recommended!

 

 

Neil English is an avid glasser and telescopist who is firmly on the side of the money conscious consumer. If you like his work, please support him by buying one of his books. Thanks for reading!

 

De Fideli.

 

Thoughts on the Pentax Papilio II 8.5 x 21 Binocular.

The Pentax Papilio II 8.5 x 21.

A work began July 9 2020

 

Preamble

Binocular: Pentax Papilio II 8.5 x 21mm

Cost: £85.99 delivered

Optics: Reverse Porro /patented converging objectives for ultra-close focus

Coatings: Fully Multi-coated

Exit Pupil: 2.47mm

Field of View: 6.0 degrees (105m @1000m/ 315ft@1000yards)

Focus Range: 18 inches to infinity

Eye Relief: 15mm

Weight: 295g

Tripod Mountable: Yes

Dimensions: 11.6 x 11.0cm(L/H)

Nitrogen Purging: No

Waterproof: No

Accessories: High quality neck strap, rain guard, carry case, instruction manual and warranty card.

 

In a previous review, I expressed my astonishment at the quality of the views served up by the Pentax Papilio II 6.5 x 21. Not only did it deliver extraordinary, ultra-close up views of the creation quite unreachable by any conventional binocular, but it also impressed when functioning in its normal way, when imaging objects at a distance. The little Papilio also has a higher power sibling, delivering a power of 8.5x with the same size objective(21mm). In this blog I would like to offer my opinions on how it performs on its own terms but also in comparison to the 6.5x model as well as a very high quality control instrument; the Leica Trinovid BCA 8 x 20, which I reviewed some time ago.

The Pentax Papilio II 8.5 x 21(left) versus the Leica Trinovid BCA 8 x 20(right).

Now, you’ll appreciate that these kinds of tests are hardly ever done by other glassing enthusiasts, partly because it will almost always be assumed that a binocular costing £85 could never compete with a glass retailing for nearly £400. Furthermore, when you are in possession of one of the most elegantly designed pocket glasses in the world, you don’t want to be told that something a lot cheaper could even compete with it. It’s only human nature to take pride in an expensive glass from a world-class optics firm, but this kind of pride, when taken too far, can blind you to greater and more important truths.

Having said that, these two compact binoculars are very different beasts; the little Leica is a roof prism binocular and is optically more complex than the Pentax Papilio II 8.5 x 21, which has a much simpler, reverse porro prism design. And because the latter is simpler, it’s easier to make well, so the rather enormous price differential between the two instruments doesn’t really tell the whole story, as I was to find out.

Let’s first take a few moments to compare the specifications on both the Leica and the 8.5x Papilio II. The Pentax delivers a power of 8.5x with a 21mm aperture objective giving an exit pupil of 2.47mm. The Leica delivers a slightly lower power of 8x with an objective aperture of 20mm and so yields a very similar exit pupil size of 2.50mm. The Leica weighs in at 235g whilst the Papilio tips the scales at 295g, So both can be carried pretty much anywhere with ease, based on weight considerations alone. There is a considerable size difference though, as you can clearly see from the photo below; the Leica is a true pocket-sized glass, capable of being folded up in such a way that it fits easily in the palm of your hand. The Papilio, while still very compact, cannot achieve this level of compactness. So, if storage size is set at an absolute premium, the Leica would be the obvious choice. That said, are there really that many circumstances where the storage size difference really matters that much? I would argue that in most realistic situations, this difference isn’t that important.

When folded down to their smallest size, the Leica Trinovid will fit any pocket while The Papilio(top) can be stashed in a jacket sized pocket.

Stray light and Internal Reflection Tests

Managing stray light inside a binocular is an important parameter in delivering contrast in a binocular image. Thankfully this is easily assessed by aiming the glass at an intense source of bright light like your iphone torch set to its maximum brightness setting and examining the images garnered through the test instrument. As I explained in my review of the lower power 6.5x Papilio II, I was quite impressed with the results I got. There were some internal reflections but they were quite feeble in comparison to many other models I have tested. The Papilio II 8.5x was not as good in comparison. It showed noticeably brighter internal reflections than the 6.5x instrument but the image was still quite clean, with very little diffused light around the light beam and no diffraction spikes. In comparison, the Leica Trinovid 8 x 20 was much better. The internal reflections were much more aggressively suppressed(but still there!) and the image was cleaner and had practically zero diffused light around the light beam. It did however, show a pronounced diffraction spike in comparison to both Papilio binoculars.

Predictably, these internal reflections were also more apparent in the 8.5x Papilio II than in its 6.5x counterpart when pointed at a bright sodium street lamp. That said, I didn’t consider this a serious flaw, as I have tested many binoculars showing considerably worse performance that still delivered good daytime views.I would however expect that the 8.5x model might show up more in the way of internal reflections when pointed at bright astronomical sources like the full Moon.

The difference in performance between the 6.5x and 8.5x in regard to controlling stray light is likely attributed to less rigorous quality control in the manufacture of these binoculars. This is probably par for the course for these low cost instruments. It is wholly realistic to expect significant inter-individual performance differences with these mass produced binos, where one sample delivers excellent stray light suppression and another delivering not so good performance in the same tests.

Veiling Glare Tests

As I explained in much more detail in a previous blog, veiling glare is a phenomenon that manifests itself in all binoculars, no matter how well designed they are. It can be seen when glassing in the open air on an overcast day while imaging a deeply shaded target, such as the edge of a wooded area. The most likely cause of this is due to reflections off the bottom lens spacers between the objective lenses, which manifests as a ‘cloudiness’ that covers much of the field reducing contrast in the binocular image. I tested the two Papilio binoculars as well as the Leica Trinovid in this regard and the results were interesting but not entirely surprising!

Veiling glare is very well suppressed in the Papilio II binoculars owing to the very deep seated location of the objective lenses well behind the anti-reflection coated glass window.

Both Papilios showed considerably less veiling glare compared with the little Leica. Imaging a shaded copse under a bright overcast July sky showed that the little butterfly binoculars were controlling this rather annoying glare much better than the far more expensive Leica glass. The reason for this is probably due to the fact that the Leica objectives are almost completely exposed to the overhead light as they are not recessed as deeply as the Papilios, which house their objective lenses well behind an optically flat glass window and so are much better protected from the ambient light. I found the differences between them to be quite striking, so much so that it could make all the difference between seeing something clearly and not seeing it at all! Thankfully, veiling glare is easy to remove from the image by simply shading the objectives with your hand, but it was interesting to see how differences in design can manifest quite striking differences in performance in this regard.

Daylight Optical Performance 

After adjusting the click-stop dioptre ring under the right eye ocular lens, I began to test the Papilio II 8.5 x 21 on a variety of targets and compared it to the Leica Trinovid BCA 8 x 20. I found this higher power Papilio to a very good optically. The images were clean and sharp and high in contrast. Indeed, they were very similar to those served up by the Leica glass. Looking critically at some tree trunks illuminated by bright sunlight showed that both glasses served up the same amount of fine detail. Contrast was a shade better in the Leica glass. Edge of field correction was also very similar in both glasses too, with both showing very mild pincushion distortion near the field stop. I did however detect slightly more lateral colour in the Papilio II than in the Leica but I felt that it did not detract much from the quality of the image.

However, I found some significant differences in depth of focus when comparing both binoculars though. The Pentax Papilio had a noticeably shallower field depth compared with the Leica and, as a result, renders it that little bit harder to focus accurately. I found myself slightly under or over shooting the focus wheel on the Papilio II before I got the precise focus required while glassing a variety of targets in the open air. This might have been expected knowing that depth of field seems to decrease with increasing binocular magnification, although in this case the difference was small (8.5x for the Papilio and 8.0x for the Leica), so the discrepancies I noted might well be due attributed to differences in design of the binoculars than anything else.

I didn’t think a difference of 0.5x increase on the Papilio II would give a noticeable increase in image scale, but I was wrong about that. This represents a 6 per cent increase in image scale and that’s large enough to notice! What this means is that the 8.5x Papilio II will give you slightly more reach with small or distant targets while glassing under good seeing conditions.

I must also report that my eyes were experiencing more in the way of blackouts in the Papilio II 8.5 x 21 compared with the Leica Trinovid though. I attribute this to my lack of practice centring my eyeball properly inside the large eyepiece cups on the Papilio. In comparison, the smaller eyecups on the Leica make centring that little bit easier to accomplish since I have had far more practice with the latter than the former glass. But I would expect these blackouts to reduce in frequency with more practice. The reader will note however that the eye relief is slightly more generous in the Papilio than on the Leica(15mm in comparison to 14mm, respectively). And since the Papilio II 8.5 x 21 has a smaller field of view than the Leica (6.0 and 6.5 degrees, respectively), it will be easier to image the entire field with it compared with the Leica glass.

Of course, one of the key ways in which the Papilio II 8.5 x 21 trumps the Leica is in close focus. The former, which has a patented converging objective lens design, enables its users to obtain stunning ultra-close views of flowers, insects, rocks, gemstones  etc, which simply cannot be achieved with the cute little Leica glass. Indeed, the close focus of the Leica Trinovid (~3 metres) is rather lacklustre in comparison with other pocket glasses I have used in the past, so if butterfly or insect viewing is your thing, the Papilio IIs will serve you much better.

Low Light Performance

Though such small aperture binoculars have limited use in low light situations, such as those encountered during dusk or dawn, I wanted to establish whether there was much of a difference, if any, between both glasses when imaging the same target under twilight conditions that we encounter here in central Scotland during the middle months of the year.  Venturing out about 10pm in the second week of July, I compared the brightness of the images served up by both the Pentax Papilio II 8.5 x 21 and the Leica Trinovid 8 x 20, by examining tree branches situated about 40 yards distant. My results were very encouraging; both glasses seemed to be delivering equally bright images under these conditions, with the nod going to the Leica. I expected this result owing to the similar exit pupil size of both instruments as well as the application of good anti-reflection coatings to the optical components. This indicated that the Papilio IIs have very good light transmission, which is an important commodity in any binocular.

Some Astronomical Tests

With all the churches shut down, I was able to carry out some tests on both the Pentax Papilio II 8.5 x 21 and the Leica Trinovid 8 x 20 in the wee small hours of Sunday July 12. Starting about 2.20am local time, I ventured out to witness a bright, last quarter Moon rising in the east, and just a few degrees above it and slightly off to the west, fiery red Mars.The sky was not fully dark but still bathed in twilight. Comparing the views in both the Papilio and the Leica, I noticed some very weak internal reflections in the Papilio which were not present in the Leica. Moving the Moon laterally from the centre to the edge, I observed that the Papilio showed some significant darkening  towards the edges but thanks to its aspherical eyepieces, the image of the Moon stayed sharp. In comparison, the Leica showed much less drop off in illumination at the edge of its field.

But things were noticeably different when I repeated the same test in the vertical direction. Again, placing the Moon in the centre of the field, and then gradually moving it to either the top or bottom field stops in both binoculars, the little Leica proved to be the clear winner. The Moon was much more strongly de-focused in the Papilio than in the Leica at the edges of the field. Keeping the Moon at the bottom edge of the field, I could compensate a bit by refocusing the Papilio to make the image of the Moon more presentable, but  alas, ruddy Mars had ballooned in size at the opposite side of the field. In comparison, the Leica image was much more together, indicating that its field of view was flatter overall and better corrected.

In addition, I judged the contrast to be significantly better in the Leica than in the Papilio. Indeed, of all the roof prism binoculars I have tested(with the possible exception of a Swarovski 10 x 42 EL Range), the Leica consistently produces the best contrast when viewing the Moon. Time and time again, the lunar vistas served up by this tiny binocular are quite simply breathtaking and have to be seen to be believed!

So, once again, the Leica pulled ahead in this rather severe test. Leica engineers have designed good field flattening lenses for the Trinovids which guarantee better edge of field correction than that exhibited in many other models. Indeed, truth be told, the Leica has edge of field performance up there with the best roof prism binoculars I have so far tested.

The superbly designed ocular lenses on the Leica have built-in field flatteners that keep the image sharp even at the edge of the field.

Ergonomics

One of the issues some binocular enthusiasts have with the Leica Trinovid 8 x 20 pertains to its small size. It is true that this glass can be quite fiddly to set the correct IPD and exact pupil position when glassing. This is much easier to achieve with the Papilios. That said, since I tend to keep the Leica eyecups in the extended position, it increases its overall physical size and so makes it easier to handle when taking out of and placing it back into its case for storage. The Leica has a very fine focusing wheel but it’s rather on the small side so could prove tricky to operate, especially in winter, when using gloves. The Pentax Papilio II, in comparison, is much easier to handle owing to its larger size which fits my hands better. What’s more, the larger focus wheel is considerably easier to negotiate even with gloves on. Indeed, one of the greatest virtues of the Pentax Papilio binoculars is the large, silky smooth focusing wheel on both models which is essential for bringing objects into focus rapidly from extreme close-up right out to infinity.

The dioptre setting on the Leica is located on the right objective. It cannot be locked in place but does hold its position firmly for many months if not disturbed. Indeed, I have never needed to adjust it since I first acquired the instrument earlier this year. In contrast, the dioptre setting on the Pentax Papilio II is located in a ring under the right ocular. It too can be adjusted by twisting the ring but it has neat little click stops that keep it firmly in place without you ever having to worry about. As I said when reviewing the 6.5x Papilio II, this is a very clever engineering solution applied to great effect on this low-cost binocular!

The Leica glass is better suited to changes in the weather however. Unlike the Papilio IIs, which are neither fog nor water proof, the Leica is filled with dry nitrogen to prevent fogging of the internal optical components in cold weather, which are therefore sealed off from the outside environment. The Leica is splash proof rather than fully waterproof, which means that it can be used in light rain or humid environments without worrying about the build up of internal moisture and, in the long term, fungal infestations. Indeed I have heard of glassers who have used the little Leica in the high humidity of tropical rain forests for weeks and months on end, where they have reported flawless performance from this tiny glass.

Additionally, the Leica binocular has special ‘Aquadura’ coatings applied to the outside lens elements to repel water droplets and dust, as well as dissipating fog accidentally built up on the lenses should the user breathe on the oculars or objectives during cold weather applications. The Papilio IIs do not have these coating technologies.

Another notable difference between both glasses pertains to their ability to be mounted to a tripod. The Leica has no such facility but the Papilio II can easily be mated to such stabilising devices.

Implications

A few weeks experience with both Papilios has proven to be very instructive. Indeed, it has forced me to radically re-think the pocket binoculars I now wish to use going forward. In my opinion, the Pentax Papilio II 6.5 x 21 is the gem of the pair. While I would rate the 8.5x as good, the 6.5x is excellent! Indeed my tests have convinced me that I could do without my Zeiss Terra 8 x 25 ED. The Pentax Papilio II 6.5 x 21 has taken its place because it offers me the same comfortable viewing experience, an even wider field of view (7.5 degrees vs 6.8 degrees) and also doubles up as an excellent field microscope when I need it, with its incredible close focus(0.5m). In fact, the entire episode triggered a selling off of a whole string of models I had recently acquired, as I don’t like hoarding equipment. The Zeiss was a very sweet instrument, and everything I have said about it still holds true, but I simply couldn’t justify holding onto two premium models in the pocket size range after my experiences with the Papilio 6.5 x 21. The latter has turned out to be a more versatile than any 8 x 25! The Zeiss went for a good price( it has excellent re-sale value) and to a good home!

My younger son, Douglas, has expressed a particular interest in the 6.5 x Papilio and has been caught hogging it and showing it off to his pals, so I decided to let him have it on the proviso that he look after it properly and I can borrow it from time to time. Now everyone in the family has a pocket or compact binocular!

The Leica Trinovid 8 x 20 has now become my instrument of choice as a general purpose pocket glass for travel and leisure. At first I treated it as somewhat of an ‘expensive toy’ that was more a curiosity than anything else, but after a while that preyed on my conscience. The Leica was designed to be used and used hard in the field. It was not designed to be an ornament or to be pampered inside a glass case.  By using it extensively in the field for hours on end, I have finally come to grips with its small exit pupil and I no longer experience any blackouts with it as I had experienced when I first used it some months back. And though the Trinovid is an expensive piece of kit as pocket glasses go, it will serve me well for decades. How do I know this? Well, check out this recent youtube review from a chap who owned and used a Leitz (the older name for Leica)10 x 25 Trinovid since the 1970s, but who recently treated himself to the newer Leica Ultravid 8 x 20.  If it served him well over all those decades since the 1970s, I figured mine would as well!

The two pocket glasses I ended up with; the Leica Trinovid BCA 8 x 20 (left) and the Pentax Papilio II 6.5 x 21 (right).

OK, time to wrap this blog up.  Thanks for reading!

 

Writers also need to eat, so if you like these reviews please consider making a purchase of one of my books. Thank you!

 

De Fideli.

Product Review: Pentax Papilio II 6.5 x 21.

The little butterfly binocular; Pentax Papilio II 6.5 x 21.

June 19 2020

 

Binocular: Pentax Papilio II 6.5 x 21mm

Cost: £109.00 delivered

Optics: Reverse Porro /patented converging objectives for ultra-close focus

Coatings: Fully Multi-coated

Exit Pupil: 3.23mm

Field of View: 7.5 degrees (132m @1000m/ 323ft@1000yards)

Focus Range: 18 inches to infinity

Eye Relief: 15mm

Weight: 290g

Tripod Mountable: Yes

Dimensions: 11.0 x 11.4cm(W/H)

Nitrogen Purging: No

Waterproof: No

Accessories: High quality neck strap, rain guard, carry case, instruction manual and warranty card.

Life is full of surprises; some good and some bad. I’m happy to report a surprise of the pleasant variety in this review, featuring the Pentax Papilio II 6.5 x 21 binocular. Though it’s been on the market for several years now, it fell below my radar partly because I became rather fixated with high quality roof prism binoculars and never considered the old classic designs using porro prisms.

Porro prism binoculars are easier to make well in comparison to their roof prism counterparts. They are also considerably less expensive compared with roof prism models of similar quality. To some, their fall from grace in recent years was not due to their inferior optical quality, but more to their larger size and ‘outdated ergonomics.’ That said, they still have a loyal following among those who appreciate fine optics.

In my recent survey of the pocket binocular market, being somewhat dismayed by the lack of credible user reviews,  I went on a shopping spree to test out literally dozens of models – all from the roof prism variety – learning that in general, you get what you pay for. But there is always something new to learn and over the last few weeks I’ve been putting this tiny little binocular through its paces.

And it’s been a revelation!

The name ‘Papilio’ derives from the Latin for butterfly. Pentax were the first company to design these reverse porro binoculars featuring a patented converging objective system that allows these instruments to focus on objects as close as 18 inches – way closer than any roof prism binocular can do. The design was an instant success and thousands of nature enthusiasts snapped them up to provide wonderful stereo-microscope-like views of flowers, leaves, insects  etc. The first generation models had a few shortcomings though, as the literature is awash with reports that the anti-reflection coatings were not up to scratch. Experienced glassers reported bright reflections off the eyepiece field lenses and annoying internal reflections, cutting down on contrast and increasing glare in strongly back-lit scenes. Some resourceful users reported ways of reducing some of these annoying shortcomings however, such as using a broad-rimmed hat to cut out peripheral glare for example, or using them in deeply shaded areas where the contrast-robbing deficiencies in the coatings were less obvious etc. Others just accepted their shortcomings and simply enjoyed them as specialised, close-focus devices to study the complexities of the creation.

But then Pentax brought out a second generation Papilio featuring much improved anti-reflection coatings on all glass surfaces. Called the Papilio II, they are offered in two models; a 6.5 x 21 and an 8.5 x 21. Being the proud owner of a superlative 8 x 20 pocket glass by Leica, I was more interested in the lower power 6.5x model, as it seemed to be the least compromised of the two and would also offer me a larger exit pupil, which is both easier to operate in general use and would prove superior to the 8.5x model in low light situations at dusk or dawn, or on heavily overcast winter days.

First Impressions

The Pentax Papilio II package.

The binocular arrived double-boxed and contained the binocular, a nice faux leather case, a high quality neck strap, a rain guard covering the ocular lenses, operating instructions and a warranty card. A quick examination of the instrument revealed that all was well; the eyepieces could be extended with a click, the focuser worked smoothly, as did the right eye dioptre ring, and the objective lenses housed inside an optically flat glass window were spotless.

To ocular end of the Pentax Papilio II 6.5 x 21 binocular.

The padded neck strap was a breeze to attach. because it has built-in clips. All one need do is push them through the two holes on the side of the instrument where they are held firmly in place. What a delightful change from threading the strap through tiny little lugs!

The body seems to be made of ABS plastic and covered in a thin layer of texturised rubber which affords excellent grip while manhandling. The double hinges are quite stiff and once the optimal IPD is set, they stay in place. The underside of the binocular has neat little thumb indentations which makes holding it a wee bit easier.

The under side of the Papilio II has thumb indentations for easy handling in the field.

The dioptre ring also served up a pleasant surprise. Instead of rotating smoothly and silently either clockwise or counter-clockwise, this dioptre has click stops that you can hear as you rotate it. At first I was a little concerned that it may not offer the precision of a smoothly rotating right eye dioptre ring, but my wife and I were able to adjust it to accommodate our different settings easily and accurately. Just like some premium roof prism binoculars which have a built-in click stop dioptre, the low cost Papilio II offers the same security against accidental movement. A very clever engineering solution!

The eyecups are plastic and covered in soft rubber. They offer three positions; fully down(for eye glass wearers) or two clicked up positions, affording a maximum eye relief of 15mm. To my relief, I found that they hold their positions very rigidly and work well in field use.

I was also very impressed with the large textured central focus wheel, which moves quickly and very smoothly with no backlash. It has a very large focus travel though, requiring 3 full rotations going from its closest focus at 18 inches right out to infinity. Good focusers are an essential feature of a binocular and I felt Pentax went that extra mile to make sure it worked well.

The objectives are housed behind an optically flat window which also has good anti-reflection coatings applied to it in order to ensure high light transmission and minimise glare. At first I thought the window would be a negative addition, as it might have introduced more unwanted reflections than I bargained for, but as you shall see shortly, I need not have worried!

The optically flat glass window protecting the moving objectives is anti-reflection coated, helping to keep contrast high in the final image.

A straight through look shows the objectives behind the glass window. Note the low reflections off the window itself.

Another really neat feature of this Pentax Papilio II binocular is the in-built thread on its underside that allows it to be mated to a tripod for more exacting work. This is a rare feature on instruments this size but I can think of many situations – both in the great outdoors and in an indoor studio – where it could prove very beneficial. What a super nice touch!

Note the built in tripod-friendly thread on the underside of the binocular.

A quick look through the instrument instantly impressed. The image of a tree trunk some 50 yards distant was bright, tack sharp and very high in contrast. I was also impressed by its wide field of view – 7.5 angular degrees ain’t too shabby! But I was literally blown away when I focused in on a flower bed of Johnson’s Blue Geraniums sat just outside my front door. Wow! The view was quite simply astounding! Placing myself just 2 feet away, the sharpness and colour fidelity of the image was excellent and the level of detail seen within the individual flowers was mesmerising!

Stray Light & Glare Test

But I took heir of myself and proceeded to test the binocular in my usual ways. So first I set up a flashlight test in my living room, by setting my iphone torch setting to its highest(read brightest) level, and standing a few metres back, I aimed the binocular into the intensely bright light beam. Wow! The result was excellent! Compared to a few high quality control instruments (all roofs), the Papilio II showed a few very minor, green coloured internal reflections with no diffraction spikes and no diffused light. Comparing it to my Zeiss Terra 8 x 25 pocket glass, the reflections in the Papilio were only slightly stronger but without any diffraction spikes. Indeed, diffraction spikes are almost a universal feature of roof prism binoculars, however well built, but porro prism instruments seem to be devoid of these. Even the venerable Leica Trinovid BCA 8 x 20 showed an obvious diffraction spike in the same test though its internal reflections were better suppressed than in the Papilio II.

The Pentax Papilio II 6.5 x 21 has excellent control of stray light, as compared with a top-performing Zeiss pocket glass costing nearly three times more!

Later in the evening, when the sodium street light came on, I once again compared the Papilio II and the Zeiss pocket glass. As expected, the Papilio II delivered excellent results; very subdued reflections and no diffraction spikes. As a glasser who cannot stand excess glare and internal reflections, I was thoroughly delighted with the results I obtained from this low-cost binocular.

So far so very good!

Collimation Test

Collimation checking and right eye dioptre adjustment are best done on a tripod.

By affixing the Papilio II to a tripod, it’s easy to check the collimation of any binocular. Aiming at the hilltops a couple of miles distant, I checked the field of view both horizontally and vertically in both barrels. The results showed very slight horziontal misalignment( as evidenced by a slight asymmetry in the edge of field views) but perfect vertical alignment. I deemed the result quite satisfactory.

A tripod-mounted binocular is also a good way to tweak the right eye dioptre by focusing on the writing on a council notice affixed to a lamp pole some 40 yards in the distance. The dioptre ring clicks as it moves clockwise or anticlockwise making it real easy to get the optimal sharpness in the right barrel when it is locked rigidly in place.

Optical Tests

I conducted my optical tests under a variety of conditions, ranging from bright afternoon daylight in the open air, shaded areas underneath the canopy of trees while walking around in a copse, performance at dusk and finally looking at some bright stars in a twilit June sky around local midnight.

Comparing the performance to my Zeiss Terra 8 x 25 ED, I was very impressed with the optical performance of the Papilio II 6.5 x 21. To my eye, the images of textured tree trunks looked equally sharp in both binoculars, with the Papilio displaying the wider field of view at a smaller image scale. Contrast was excellent in both instruments, which both sport very large sweet spots, and only showing slight softening at the extreme edge of the field. The Papilio features aspherical ocular lenses which keeps off-axis aberrations at bay. In this respect, the Papilio II produced less field curvature(as evidenced by aiming at a telephone pole a few tens of yards distant and moving the pole to the edge of the field) than the Zeiss. Indeed, I pulled out my wife’s Opticron Aspheric LE 8 x 25 which also sports aspherical ocular lenses and displays superior edge sharpness to the Zeiss Terra, as reported in a previous blog. Well, the Papilio II proved fully the equal of the Opticron pocket glass on the same target!

The Pentax Papilio II 6.5 x 21( left) and the Opticron Aspheric LE 8x 25 (right).

Under the brightest daylight conditions it is easy to detect reflections off one or more of the ocular lenses as this manifests as a subtle circular glare disc covering much of the field. Alas, these annoying reflections are all too common on a lot of instruments that skimp on their application of anti-reflection coatings. I was very pleased to see that the Papilio II also passed this test with flying colours – that is, it was not present. Chromatic aberration was pretty much non-existent even when pointed at a tough target like a television aerial against a bright overcast sky.

Comparing the Papilio II to my Zeiss 8 x 25 roof prism binocular under the shade of  conifer trees near my home, I found both binoculars to yield up equally bright and sharp images of ground vegetation just a few metres away. When I did the same tests with the Opticron, I felt the Papilio served up slightly brighter images although the sharpness was judged to be more or less the same.

Going out at dusk around 10.15 pm, I compared the brightness of the images of tree branches about 50 yards distant served up by the Pentax Papilio II, the Zeiss Terra ED 8 x 25 and my Leica Trinovid 8 x 20. The Papilio II and the Zeiss pocket glass threw up images that were about equally bright, with the nod going to the Zeiss ( but only just!). Comparing the Trinovid 8 x 20 to the Papilio II in similar tests showed that the images were noticeably brighter in the latter instrument.

The Leica Trinovid BCA 8 x 20 (left) and the Pentax Papilio 6.5 x 21(right).

All in all, these were excellent results showing that the light transmission efficiency of the Papilio was very good indeed based on Zeiss’ published data on the Terra glass, which has 88 per cent transmission. The dimmer images served up by the Trinovid was easily explained in terms of its smaller exit pupil (2.50mm compared with 3.23mm).

My final optical tests were conducted under a twilit night sky ’round about local midnight. I aimed the binocular at the bright summer star, Vega, and compared the views in both the Zeiss and the Papilio II. Both instruments focused Vega down to a crisp, white pinpoint that held its sharpness across nearly all of the field. Moving the instruments horizontally showed better off axis performance than those exhibited by moving the star up and down, to the top and bottom of the field, respectively. The only difference I could detect was the darker sky hinterland in the 8 x 25 Zeiss pocket glass, perhaps owing to its higher magnification.  But even so, the differences weren’t huge.

These tests convinced me that the Pentax Papilio II 6.5 x 21 has excellent optics, especially for its very modest price tag. Its simpler design to roof prism binoculars means it has less optical components overall, and the combination of aspherical ocular lenses, high quality Bak 4 prisms and fully multi-coated optics all contribute to this high optical field performance.

Further Notes from the Field

Using the reverse porro prism designed Papilio II takes a bit of getting used to. At first, its strange body shape reminded me of a scene from a Star Wars Movie when Luke Skywalker used weird looking binoculars to monitor the movements of marauding Sandmen lol. That said, it’s quite easy to hold steady and most anyone can use it, including kids.

Though it is just as lightweight and portable as a pocket binocular, it doesn’t fold nearly so compactly as a dual hinged pocket glass like the Zeiss Terra 8 x 25, as shown below:

Though it weighs just as little as a light weight pocket binocular like the Zeiss Terra 8 x 25(bottom), it cannot fold up quite so small but will fit in a large coat pocket or a ruck sack.

The Pentax Papilio II 6.5 x 21 can be used as a decent birding binocular, with its quality optics and fairly large and very well corrected field of view.  Its super-fast focus wheel also helps in this regard. One drawback of its lower magnifying power compared with more conventional glasses (which almost invariably use powers of 7x to 10x) is reduced range. Sometimes you just need 8x or 10x to bring the subject sufficiently close in order to get a good view of it. And 6.5x may not be the best choice for a twitcher, where the subject is heavily camouflaged, small or located at a lengthy distance from the user. For close-range work (read within a couple of hundred yards) it should work well though. Its small aperture will also limit its use to bright daylight conditions most of the time, and thus will be less suitable for work when lighting is compromised, such as at dawn or dusk, in which a larger aperture glass would serve you better.

The instrument is absolutely head and shoulders above any other instrument on the market if your speciality is close-up work, like studying insects, flowers, rocks and minerals. It will also prove indispensable to artists who paint still life scenes indoors, where the instrument can be permanently mounted on a clamp or tripod, where the subject can be examined in exquisite detail under optimal lighting conditions. It also serves as a very effective stereo microscope, affording very comfortable and immersive views of a wide variety of subjects.

I have noted that for such close-up work, the Papilio II 6.5 x 21 seems to provide greater than advertised magnification. When viewing flowers at 18 inches, for example, the power seems closer to 7.5x or 8x and not the advertised 6.5x. This is probably true of the 8.5 x 21 instrument as well, where a power of 10x or more might be expected during these close-range observations.

The binocular is not weather or water proof, which might be a negating factor in choosing it for general purpose viewing or bird watching. In cold weather, it will fog up when brought from the outside to a warm indoor room. I would not recommend using the instrument in rainy or showery conditions. But there are ways to protect it from fogging up internally. For example, by placing the instrument back in its case with the rain guard on prior to bringing it indoors is a good move, as would storing the instrument with an effective desiccant, like silica gel, will help keep moisture at bay and prolong its shelf life, especially if you live in humid climes.

The instrument is not really recommended for astronomical use, though it will serve up very nice news of illuminated cityscapes owing to its good control of stray light within the optical train. That said, it ought to serve up nice images of the Moon and bring some of the brighter deep sky objects into view from a dark, country sky.

I have noted that the optically flat glass window protecting the objective lenses is a magnet for attracting pollen. Not a big deal in the scheme of things, but something to bear in mind. You’ll need a soft lens brush to keep the window clean. I tend to give it a brush down after any prolonged spell(more than 30 minutes or so) outdoors.

The glass window protecting the objective lenses attracts a lot of pollen so will require regular brush down after prolonged field use.

Another niggle reported by some users of the Pentax Papilio II binoculars is that the supplied carry case is too small to comfortably house the instrument when the neck strap is attached. And while removing the strap is one solution, it might not be to the liking of some individuals who wish to use it in the spur of the moment. I have found a solution of sorts, by placing the binocular in the case while feeding the two ends of the strap out from both ends of the case cover. The strong velcro seal is plenty strong enough to hold the binocular in place inside the case and the straps can be used to carry it about!

The neck strap can also double up as carry strap for the case & binocular.

As always, I store the binocular inside its case with a sachet of silica gel and store it in a cool( 60 F), dry and well ventilated pantry to protect against fungal infestation.

Conclusions: The Pentax Papilio II 6.5 x 21 was a very pleasant surprise. For its modest cost of just over £100, you get very decent classic porro prism optics with unbeatable close-focus capability. I think every binocular enthusiast should own one! Far from being a one-trick-pony, it will serve as a very versatile instrument for casual viewing, nature study and bird watching. Just understand that it can’t be used in rainy conditions and needs protection from internal moisture build up in humid climates requiring extra care when storing for long-lived use.

Highly Recommended!

Neil English is the author of seven books in amateur and professional astronomy. If you like his work, please consider purchasing one of his books. Thanks for reading!

De Fideli.

Adventures with a Pocket Binocular Part II.

A work commenced November 11, Anno Domini 2019.

Part II

Subject to Copyright. Completed text will cite references & bibliography .

 

 

Taming a Flame

Caveman’s telly.

The second week of February 2020 brought cold and tempestuous weather to Britain, with the arrival of Storm Ciara. Just as we were preparing our family evening meal on Sunday February 9, the storm caused a power cut which left us and our fellow villagers without electricity for a few hours. So out came the candles and on went the coal fire to keep us out of total darkness and comfortably warm. I have always been somewhat in awe of fire and fetched my pocket glass to observe the cadence of its flames as they rose upwards into the chimney column. Because of their excellent close focus, my pocket glasses can entertain me as much indoors as they can out of doors!

As I drank up the wondrous display of light and colour of the coal fire from the comfort of my couch just a few metres away, my mind reflected on the importance of fire to the progress of humanity over the milennia. Nature not only produced the fuels but also the reactive gas(oxygen) needed for fires to occur. They are thus vital components of a life-bearing planet. With an atmosphere of 21 per cent oxygen, it is just right to allow fuels(reduced carbon substrates) to ignite and generate heat and light. If the percentage of oxygen in our atmopshere were only a little higher, spontaneous combustion would be much more common and many areas of the world would experience the devastating effects recently suffered by the people and biota of Australia. If the oxygen levels were lower, we would be unable to extract enough chemical energy from food to allow us to do much in the way of higher cognitive activities such as talking, calculating and praying.

The unique ability of humans to create and control fire is probably the single most important activity that launched the high technology societies in which we now live. In its basic form, it provided our hunter-gatherer ancestors with warmth and light on cold winter nights, which allowed us to work for longer and so boosting human productivity. Its intense heat protected us from hungry predators stalking us out in the dead of night. By cooking food, it killed germs that might have made us sick. The intense heat of the fire also helped break down hard-to-digest foods, enabling us to extract their nutrients more effectively. With fire, humans could greatly expand the varieties of territories we could eke out a living in. No longer were mountains and frozen northern wastelands verboten. Fire must have triggered the largest exodus of humans from the warm grasslands of East Africa/Middle East, where we probably first emerged from after our forced expulsion from the Garden of Eden.

Our innate capacity to experiment led to further discoveries allied to fire. We learned to ‘cook’ wood, yielding the amazing substance we now call charcoal, and with that we could generate temperatures far in excess of any normal fire(up to a 1000C in fact!). Charcoal is a wonderful reducing agent, empowering our distant ancestors with the ability to ‘pull’ metals from ores; copper, tin, lead and the creation of alloys like bronze. Once we understood how to use air to increase the temperature of furnaces, the extraction of iron finally became possible. The age of metallurgy was born and with it the great transformation of our lives. Without a knowledge of combustion, we would have no ceramics, no cars, buses or trains, no computers, iphones or tablets; no skyrockets to scale heaven.

And no glass to peer through!

My binoculars would not exist were it not for fire!

And yet there are still deeper things to ponder. Why, for instance, doesn’t the coal I fetch from our bunker not react with the oxygen that surrounds it? Why, as creatures who ‘slow burn’ our food, do we not burst into flames? The answer is not all obvious, but pertains to the stability of both oxygen and coal at ordinary terrestrial temperatures. To burn coal, I must elevate its energy enough to initate the reaction, that is, by igniting the coal with a spark. And deep inside the countless trillions of cells that comprise the human body, enzymes(biological catalysts) lower the activation energy enough for our reduced foodstuffs to react with the molecular oxygen delivered to our body cells via myriad haemoglobin molecules.

But our ability to tame a flame is also related to our physical size. Think on it: if we were as small as a mouse say, we would be unable to get close enough to a fire to keep it fuelled without getting seriously injured. We’d also lack the muscle power to bring enough fuel in the form of chopped wood or dry brush to sustain the same fire. But humans are large enough(1.5 to 2m), and endowed with long enough arms with an ingenious manipulative tool at their ends(fingers with an opposable thumb), and with muscles powerful enough to chop and carry wood and lay it on a fire with outstreched arms, so keeping a safe distance from its desctructive flames.

And if we were significantly larger, gravitational forces would put much higher strains on our limbs. Carrying anything would much more difficult. Biophysicists have long known that simple power laws govern how body weight and limb strength scale with increasing height. Weight scales as the cube of height, but limb strength only scales with the square of height. That means that if we were much taller, strenuous physical activities would become far more challenging and even downright dangerous. Our limbs would shatter under their own weight and fumbling Prometheus falling into a fire would be a distinct possibility. The same principles explain why, upon faltering in a similar situation, a little child would emerge unscathed.

Can our physical size and the chemical and physical properties of our atmosphere that allow fires to be tamed and pressed into service by our kind be just coincidence? Is this just another serendipitous chain of events that happened to occur on our planet? Most certainly not! The godless naturalists can provide no credible answers to these questions.

They are, quite literally, left in the dark!

On the otherhand, a Creator God – an Unquenchable Fire – who designed this world for His human imagers to transform its natural resources seems far more probable to my mind.

Come, let us bow down in worship,
let us kneel before the Lord our Maker;
for he is our God and we are the people of his pasture,
the flock under his care.

Psalm 95:6-7

A Worthy Upgrade

The Leica Trinovid BCA 8 x 20 pocket binocular package.

During the first two weeks of January 2020, I had the opportunity to test drive a Leica Trinovid BCA 8 x 20 pocket glass kindly lent to me by a fellow villager. You can read about my opinions of that instrument here. As that report shows, I was very impressed with its wonderful optical and mechanical quality, but still a little concerned about how much use I would realsitically get out of a glass with very small, 20mm objective lenses. After some cogitation and deliberation, I decided that having two 8 x 25 units(the Opticron Aspheric LE WP and the Zeiss Terra ED) could not be justified, and so I gifted my Opticron to my next-door neighbour and invested in what is arguably one the highest quality achromatic(read non-ED) pocket glasses money can buy. Conducting some price comparisons across the internet, I managed to track down a UK-based seller offering the Trinovid for a very good price and I pulled the trigger.

The package arrived in perfect nick. What I received(see photo above) was a small box (actually double-boxed) with the Leica binocular safely packed inside a soft but rather oversized carry case, a small neckstrap, a comprehensive user manual, a test certificate and a booklet containing details of its 10-year warranty. The binocular had no eyepiece or objective lens caps though, and not even so much as a lens cloth thrown in for good measure!

My neighbour was thrilled to bits to accept the Opticron – a high quality pocket glass  – but I was equally thrilled to finally own arguably one the smallest, useful pocket glasses in existence. And, as my subsequent tests showed, the little Leica proved to be every bit as good as the unit I tested a few short weeks ago.

The little 8 x 20 Leica passed my flashflight tests with flying colours; it was just as clean and devoid of internal reflections as the earlier unit I investigated and delivered pin sharp images rich in contrast almost from edge to edge. There is no question that the quality control on these high-end pocket glasses is remarkably consistent. Optically, the Leica Trinovid BCA 8 x 20 is unquestionably a step up from the Opticron in terms of sharpness and contrast. Indeed, it is right up there with the Zeiss Terra 8 x 25, but in smaller, more elegant frame.

Once I had done my testing, I registered the instrument on Leica’s sports optics website(the serial number being printed under the right eyecup).

The Leica Trinovid BCA 8 x 20(left) has a smaller frame to the Zeiss Terra ED 8 x 25 (right).

As much of my work on telescopes over the last decade has involved raising amateur awareness of the wonderful properties of well-made achromatic refractors, I was thrilled to see that a top company like Leica was creating state-of-the-art miniature binoculars using traditional crown and flint glass. It showed me once and for all that excellent binocular optics doesn’t necessarily require the use of low dispersion lenses. Rather, it’s more to do with the precise figuring of the glass, as well as the application of state-of-the-art coatings to all optical surfaces that delivers this degree of excellence.

Both the Zeiss and the Leica are endowed with similar, high-quality optics, but one has ED Schott glass (the Zeiss) comprising one or more of its objective elements, while the Leica does not. But if I were to make an aperture stop for the Zeiss, reducing its effective aperture to 20mm, I would in effect have two instruments operating at 8 x 20 and with the same exit pupil(2.5mm). So the biggest difference between them would be the ED component and that would allow me to investigate claims made by a number of individuals over the years; specifically in relation to the brightness of the images served up by ED and non-ED optics. Is there any or much truth in this claim?

So I set to work performing some experiments in low light conditions, carefully comparing the images served up by both pocket glasses. I hope to report back on this in a later post.

A Better Case for a New Pocket Glass

The Leica binocular came with a soft padded case that was too large to fit it well. As you can see from the image below, the binocular has quite a bit of wiggle room inside the case and even when it’s closed, dust can easily enter and accumulate over time. This is especially the case(lol) as the instrument was not supplied with endcaps to cover the ocular and objective lenses.

The Leica logoed soft carry case is too large to fit the little Leica 8 x 20 and is not a very good deterrant against dust when the binocular has no dust caps.

I felt that there must be a better solution to this storage problem. So, after taking into account the dimensions of the Leica glass, I searched online for a suitable replacement. Eventually, I came across a tiny clamshell case, similar to the one I received with the Zeiss Terra but smaller again. Here is what it looks like:

A tiny, anti-shock clamshell case that zips shut.

Here is another photo of the clamshell case compared with the original case for reference:

The Clamshell case is significantly smaller than the supplied Leica soft padded case.

Costing just £6.99 inclusive of delivery, the clamshell case is shockproof and can be zip-closed.

The clamshell opens up revealing the storage space inside. Note the sachet of silica gel.

To my relief the Leica binocular fitted the hard clamshell case perfectly and can even accommodate the binocular with the eyecups kept up for quicker deployment.

The fully folded Leica 8x 20 sitting inside the new case.

The case also allows the Leica binocular to be stored with the eyepieces fully extended upward for quicker deployment.

I was delighted with the new case as it affords far better protection of the optics and is even easier to store away owing to its very small dimensions. The image below shows its size in comparison to the Zeiss Terra case.

Two good clamshells for two fine pocket glasses.

This should serve as an excellent storage case for the Leica pocket glass, protecting it from dust and moisture; an important issue since the instrument is splashproof but not waterproof.

Maybe I should contact Leica Sports Optics with this suggestion?

A Triumph for Aperture & Ergonomics!

Pure sweet!

Both the Leica Trinovid BCA 8 x 20 and the Zeiss Terra ED 8 x 25 are top-notch optical performers. But while the Leica is significantly more expensive than the Zeiss, it is the latter instrument that will prove to be the more versatile. Let’s compare some of the specifications to see why this is the case.

The Zeiss has a larger aperture and bigger exit pupil, making it significantly more effective in low light conditions and for observing the night sky.  The larger exit pupil (3.125mm) also makes it considerably easier to line up your eye pupils rendering the views more immersive and comfortable. The Zeiss has a much larger focus wheel making it the easy choice in cold weather where gloves are worn. In addition, the Zeiss Terra is more pleasant to hold in cold weather since the thermal conduction of its polymer frame is much lower than the aluminium frame of the Leica, which always feels very cold to touch in cold winter conditions.

The Zeiss has better eye relief than the Leica(16mm and 14mm, respectively) making it easier for eye glass wearers to engage with the entire field of view.  What is more, the Zeiss Terra has a considerably larger frame than the Leica pocket glass rendering it much more stable to hold steady during prolonged field use. It also has a noticeably wider field of view than the Leica(6.8 degrees as opposed to 6.3 degrees). And while the build quality is definitely better in the little Leica pocket glass, the Zeiss is really not that far behind it.

I like to think that the ethos behind the design of the Zeiss Terra pocket glass is different to that of the Leica. The frame of the Zeiss is constructed from modern, strong but lightweight materials (fibreglass-reinforced polyamide). Indeed, it only weighs about 75 grams more than the Leica glass. In addition, the Zeiss is fully fogproof and waterproof, whilst the Leica is merely splashproof and so the former has a distinct edge over the latter when moving from cold, damp conditions to a wam, interior environment. One other issue is worth mentioning; the Leica Trinovid BCA is much more fiddly to deploy than the Zeiss. Have you ever tried getting your optimal interpupillary distance with the Leica when attempting to view the night sky in the dark? It can be downright frustrating to say the least! Not so with the Zeiss Terra!

Seen in this light, it’s relatively easy to see why the Zeiss would be my first choice for standard field use. It just ticks so many more boxes than the Leica. Instead of feeling slightly anxious about using a small, ornate pocket glass, that anxiety all but disappears while using the Zeiss. That said, I can see where the Leica might be better suited than the Zeiss. Because the Leica is smaller and has less garish external colours than the Zeiss, it would probably be suited that little bit better to watching sports events from a distance or during an evening at the theatre. Its superior control of glare, internal reflections and less intense diffraction spikes when looking at bright artificial light sources also makes it eminently qualified for observing urban nightscapes and the occasional bout of ‘take anywhere’ tomfoolery.

All of this resonates well with experiences I have had when comparing smaller grab ‘n’ go refractors to my upgraded 130mm Newtonian reflector. Despite being less expensive than the refractors, the larger Newtonian proved the better choice time and time again, showing that you don’t always get what you pay for! Just like the Zeiss Terra, the 130mm Newtonian simply represents more bang for your buck!

Does ED glass in a binocular result in brighter images?

Anyone who has followed my blogs over the years will know that I am sceptical of the claims made by fanatics of ED glass. I found much of their claims somewhat pretentious, including statements like, ” Apos resolve binary stars better than traditional achromats and Newtonian reflectors.” My own tests conducted both in the field and backed up by numerous historical references showed otherwise, which is one of the reasons I got rid of a whole raft of refractors with ED glass and replaced them with much more economical and powerful Newtonian reflectors. It’s relatively easy to find comments about small, low- power ED binoculars where the following claim is  often made, “Binoculars containing ED glass give brighter images than those using traditional traditional crown and flint glass.”

Now, I can certainly see why binocular objectives containing ED glass might focus the visible wavelengths of light they collect that little bit more tightly than those without such elements, which might give them an edge in terms of producing a slightly brighter image, but not so much to make the difference ‘obvious’ or ‘immediately apparent.’ What I did discover is that it is often the quality of coatings applied to the lenses and prisms that result in noticeable differences in image brightness, since more efficient coatings result in a greater light transmission to the eyes. My curiosity was further piqued when I came across this short youtube review, where the presenter noted that a binocular with so-called ‘HD coatings'(read dielectric) produced a much more dramatic effect on image brightness than ED glass-containing instruments with the same specifications utilising non-dielectric(lower reflectivity) coatings.

So I wanted to test the claim that ED glass containing binoculars result in brighter images by conducting a series of observations using three binoculars; my Zeiss Terra ED 8 x 25(containing Schott ED glass and retailing for £270), my Leica Trinovid BCA 8 x 20(bought for £319) and my Celestron Trailseeker 8x 32 binocular(a £126 purchase). The latter instruments have high quality coatings but do not include ED glass containing objectives. The Celestron Trailseeker, in particular, has dielectric coatings applied to the roof prisms, creating the same ‘HD images’ to the Hawke Frontier X 8 x 32 model featured in the youtube clip linked to above. Surprisingly, Leica do not appear to publish details of the coatings they apply to their optical components and no data on its light transmission. The Zeiss Terra ED has a published light transmission of 88 per cent, which you can find on the Zeiss sports optics website.

The stopped down Zeiss Terra ED, effectively working as an 8 x 20 unit.

In order to make the comparison as fair as possible, I made a 20mm aperture stop for the Terra, cutting its effective aperture from 25mm to 20mm but still retaining a magnification of 8x. I then compared the performance of this stopped down binocular to the Leica 8 x 20 (at full aperture) under low light conditions at dusk, when the light was rapidly fading in the evening. I conducted such tests on three separate occasions and, in each case, I elicited the opinions of a number of other individuals, my wife and a few of my students, to ensure that the results were consistent with my own. The target was a tree branch located about 50 yards in the distance. Consensus was reached. The stopped down Terra ED yielded a very slightly brighter image than the Leica 8 x 20.

The stopped down Celestron Trailseeker 8 x 32 working at an effective aperture of 25mm.

But then I set up a similar set of experiments comparing a stopped down Celestron Trailseeker 8 x 32 with an effective aperture of 25mm with the Zeiss Terra ED 8 x 25 at full aperture(so also at 25mm). As with the first experiment, I canvassed the opinions of a couple of my students and my wife on the same target and under late, dusky lighting conditions. The results were very surprising! 3 out of four of us(including yours truly) reported the Celestron to have an edge in brightness over the Zeiss, while a fourth observer reported essentially equal brightnesses in both the stopped down Celestron and the Zeiss at full aperture.

Conclusions: The presence of ED glass did not result in any dramatic increases in brightness in both tests and when compared against the non-ED Celestron, the results seemed to indicate that it had, in fact, a slight edge over the ED containing Zeiss Terra. This further suggested that the Celestron Trailseeker had a light transmission of at least 88 per cent (and possibly a little bit higher), indicating that (as I suspected from other tests) it is indeed a highly efficient light gathering instrument. The results for the Leica Trinovid might also suggest that it may actually have a slightly lower transmission than the Zeiss(88 per cent), although I was unable to verify this in practice owing to the lack of published data on this Leica binocular.

I would warmly encourage other binocular enthusiasts to conduct similar experiments if they have the means. 

These experiments deepen my conviction that the marketing of ED glass in small, low-power binoculars like these, is yet another clever ploy to lure unsuspecting consumers to choose ED-containing binoculars over their non-ED counterparts based on misleading, if not false, claims. Don’t be gulible; never buy a binocular based solely on the presence or absence of low dispersion (ED glass). Check out the other specifications that an instrument offers before parting with your hard earned cash, or try before you buy.

A Vibrant Star Cluster in Coma Berenices

On the Lion’s back; Melotte 111 in Coma Berenices, as seen on page 125 of our guide book.

February has proven to be a very unsettled month weatherwise. The UK has endured not one, but two big storms; Ciara and Denis, causing widespread flooding and general havoc with many communities across the country. But even amidst this grotty weather, the night sky still presents opportunities to observe it, if only for a few minutes at a time. And small binoculars are the ideal instrument to use in these very unsettled conditions, as they require no set up time. If a clear spell presents itself, I’m away out to have a gander.

By mid-February, the constellation of Leo approaches the meridian around local midnight; a sure sign that Spring is on the way. And over in the east, other signs of vernality present themselves, particularly brilliant orange Arcturus, which has cleared the murky horizon and is rising ever higher in the sky, together with the many interesting stars that collectively inhabit the constellation of Bootes. Looking over to the northeast, the bright summer star, Vega, is reassertting itself, while setting in the west, Orion and Taurus are now past their glory days.

This time of year, I like to visit a conspicuous patch of sky just east of the hind legs of the celestial Lion. Easy to pick up in the pocket glass, the famous Coma Cluster( Melotte 111) is no trouble to track down in a dark, moonless sky as a smattering of 4th and 5th magnitude stars concentrated into an area spanning some 5 degrees. Light pollution in towns and cities often drowns out even its brightest members, but from a dark country sky, the Coma Cluster is a fine naked eye sight, with at least half a dozen members being clearly visible to my unaided eyes. But the view greatly grows in majesty when examined with a small binocular. The 8 x 25 Terra frames the cluster very well, where the characteristic ‘V’ shaped stellar configuration makes it child’s play to identify. Several dozen suns are easily discerned in this cluster in a pocket glass and up to 80 members can be pulled out of the dark with larger glasses.

Our guidebook on page 124 informs us that the centre of the cluster is estimated to be about 285 light years away, with its many main sequence stars estimated to have an age of approximately half a billion years. Such a vast amount of time is more than sufficient to prize its stars apart, which goes a long way to explaining why the cluster is so large and sprawling as seen in the pocket glass.  I made a sketch of the Coma Cluster last season using a larger binocular, which is reproduced below for interest.

Insights from an Old Book

Leafing through an old book can reveal  some surprising insights.

My two pocket glasses serve up breathtaking images of the creation. In terms of absolute optical quality, millimetre for millimetre, I would give the edge to the Leica 8 x 20. Yet, in comparing and constrasting it to the Zeiss Terra, I have noted a couple of other ways in which the latter instrument pulls ahead of the smaller glass. The first thing is close focus distance; the Zeiss pocket binocular can focus on objects as close as 1.4m away, while the Leica fares considerable worse in this regard, at about 1.8m. This will likely prove important going forward, as I am fond of observing insects, rock formations, colourful mushrooms and other fungi, as well as flowers at very close range. The Zeiss’ wider field of view will also make those close up views more compelling.

The second thing I have noticed is that, with the exception of strongly illuminated(read sunny) daylight scenes, the Zeiss pocket glass serves up noticeably brighter images. And this is true whether fooling around indoors, glassing out of doors on overcast days and in shaded areas like woods and glades. That the Zeiss was producing brighter images under a wide range of conditions surprised me a little until I happened to pick up an old book from my library, written by the late Leif J. Robinson, former editor of Sky & Telescope Magazine, entitled Outdoor Optics. On page 15 of that text, there is a graph(shown below) of pupil diameter versus age for dark-adapted eyes, as well as how the exit pupil behaves under so-called ‘office illumination.’

Exit pupil size versus age for dark-adapted eyes and under office illunination. Source; Outdoor Optics (1990), by Leif J. Robinson.

The ambient brightness (luminance) is measured in units called Lux, where 1 Lux is 1 lumen per square metre. In this wikilink, it gives the luminance values for various illuminated conditions, including office lighting, which can be anywhere from 300 to 500 Lux. Heavily overcast days can have Lux values as low as 100 though, while observing under the canopy of trees in wooded environments might be expected to be even lower. Looking at the size of the exit pupil under office illumination for my age(51) gives a value of ~3.5mm. Although the particular details of how my own pupil behaves is still unknown to me, these results go some way to explaining why the Zeiss Terra(with an exit pupil of 3.13mm) pulls ahead of the Leica (with a smaller exit puipl of 2.5mm)under these conditions. And gathering more light means that I can discern finer details in many dull or dimly lit scenes of extended objects using the larger 8 x 25 glass.

I intend to investigate this phenomenon further by taking measurements of the luminance under differing lighting conditions and relating this to what my eyes discern using these small pocket glasses. Accordingly, I have ordered up a luminance meter to perform these experiments, and will report back on this matter at a later date.

A New Colour Variant of the Zeiss Terra Pocket Now Available!

Remember how I described the Zeiss Terra 8 x 25 as having rather garish colours that might attract unwanted attention from the members of a crowd at sporting events? Well, I just recently discovered that Zeiss are now offering the Terra in not one, but two colour schemes. As well as the black, blue and grey livery on the original Terra, they now offer it in black, white and blue. And here’s what it looks like:

Zeiss Terra ED Pocket 8x25 Binoculars - Black/Black

Maybe someone from Zeiss was reading my blogs lol?

I think it’s rather handsome; don’t you? Source here.

Hooking up with the Leica Sports Optics Group

I had a few questions about the Leica Trinovid BCA 8 x 20 and decided to contact the sports optics group in the UK with a couple of questions that I was unclear about. The first question I asked them was whether or not the outer lenses of the Trinovid were treated with AquaDura coating. This nanotechnology changes the surface tension of water and oily dirt that happens to form on the glass, causing smaller droplets to coallesce into larger drops, which in turn are much more easily discarded from the lens surface under gravity. It also acts as protective barrier against abrasive forces such as scratching. The reason I enquired about this coating was that the user manual I received did not explicitly state that it had been applied but the online PDF  of the binocular’s technical data did state that AquaDura was indeed applied to the outer lenses. In addition, I asked them to clarify what ‘splashproof’ meant.

Well within 24 hours, I heard back from Leica, who were able to confirm that AquaDura was indeed applied to the outer lenses. They also suggested a way I could test this by breathing heavily on either the ocular or objective lenses to create a temporary fog and watching how this would disappear within seconds. Sure enough, that fog disappeared rapidly. Indeed, I performed the fog test on both the Leica and my Celestron 8 x 32 and was able to verify that the condensed moisture disappeared within seconds on the Leica but lingered far longer on the Celestron ocular lens. To illustrate this, I took a photograph of both ocular lenses just after I fogged them up and again 10 seconds later. You can see that the Leica lens was free of moisture but the Celestron had not yet de-misted.

Performing the fogging test. At the top is the Celestron ocular lens and on the bottom, the Leica ocular lens, just moments after they were fogged up.

The same ocular lenses as seen 10 seconds later. Note that the fog has disappeared from the Leica ocular but is still prevalent on the Celestron.

They were also able to clarify that ‘splashproof’ meant that they would hold up fine in light rain but were not advisable to use in heavy rain or on a boat.

I later contacted Leica UK to tell them about the alternative carry case I acquired to better protect the little Trinovid against the elements. Indeed, I dispatched the same sequence of images I presented earlier in this blog to them. I wasn’t really expecting a reply but within hours I got a very nice e-mail from one of the group members (Tizia). Here is what she had to say:

Leica Camera Onlinestore UK Onlinestore.uk@leica-camera.com
to: Neil English <neilenglish40@googlemail.com>
date: 24 Feb 2020, 16:15
subject: Re: Hardcase for Leica Trinovid BCA 8 x20
mailed-by: leica-camera.com

Hi Neil,

Thanks for sharing! That’s brilliant. What brand is this case? I will make a note of it to let future customers know in case they are looking for a case as well.

Best wishes,
Tizia

[signature_1723328913]

store.leica-camera.com/uk<http://store.leica-camera.com/uk>

I think they liked the idea. And after my teaching this evening, I sent her on the amazon link to the clamshell.

Who knows, maybe Leica might bring out their own version of this nifty little carry case in the near future?

Rise of the Daffodils

The first daffodils grace us with their radiant colour.

On the last day of February, my eldest son and I took off for a walk around the grounds of Culcreuch Castle Estate. Though the weather for most of the month has been downright horrid, no snow has settled in the valley this winter, but it seems to come and go on the hilltops.  During our walk I was delighted to see that the first daffodils had begun to flower. Unlike the south of Britain, where daffodils spring up a few weeks earlier owing to its milder climate, nature seems altogether more pedestrian this far north. Still, the days have lengtened considerably by now, with sunset occurring near 6pm local time. And with longer days, the intensity of sunlight grows noticeably stronger, its rays beginning to bring some warmth to an upturned face, and making observing with the pocket binocular ever more worthwhile.

Nature seems to have been stirred into action in other ways though. I’ve been glassing the  corbies, mostly of the carrion variety, that roost in the conifer trees to the west of the house, where I have observed them carrying nest-building materials; twigs, mosses and the like, in their sturdy beaks in preparation for the arrival of the next generation. Their deep and resonant ‘kaaring’ has become noticeably louder and they seem more anxious than they’ve been earlier in the winter. My neighbours seem to consider them as nothing more than noisy nuisances, but I have always had a soft spot for them.

And there’s also been an unexpected return of one of the Magpies to the Rowan tree in my garden. The original family are still around but on one Sunday afternoon a few weeks back, my wife and I witnessed at first hand some very vicious behaviour within their ranks. One of the group seemed to have been singled out as weaker or less desirable than the others and was attacked by two other Magpies in the group. They forced it to the ground and were pecking and kicking at it, with the obvious intention to injure or even kill it. Were it not for the intervention of my wife, the poor creature might have died. Fast forward a week or so and lo and behold, a solitary Magpie returned in the evening, resting near the centre of the tree which afforded it more protection on all sides by its wiry branches. It looked lonely; almost forlorn.  Alas, I have ventured out to see if it returned on other nights since then, but thus far, there has been no sign of it. I do hope it has survived.

The solitary Magpie hunkering down at the centre of the Rowan tree on the evening of February 24 2020.

Further Experiments on Light

The light meter used to study the relationship between ambient lighting and the brightness of binocular images.

I ordered up a light meter in order to conduct some more experiments on the relationship between light intensity and the perecived brightness of the images served up by the Zeiss Terra and the Leica. It’s easy to use and has been very educational. On bright days, in  a clear, blue sky and in direct sunlight, light intensity can reach 50kiloLux. But as soon as a cloud covers the Sun, the intensity falls to half that level. Dull overcast days (for late February) in the open air yield values of the order of 6-7 kiloLux. Indoors is another matter though. For example, the brightness in my living room under regular illumination falls to just 50 Lux and under these conditions, the larger exit pupil of the Zeiss pocket glass clearly show brighter images. The same is true when viewing objects under brighter indoor lighting levels, such as my kitchen (300 Lux). What is more, observing through a window or from an open door during most any daylight conditions registers values of the order 400 to 500 Lux. My son and I both confirmed that the Zeiss clearly shows a brighter image than the Leica when observing under these conditions, and the readings I have thus far obtained deep inside a forested canopy under the shade of conifer trees show values of about 1.2 and 1.0 kiloLux in strong (overcast) afternoon illumination. Here again, the Zeiss pulls noticeeably ahead in terms of serving up brighter images. My preliminary results with the light meter suggest that at luminance levels less than a few kiloLux, the Zeiss will serve up brighter images under pretty much any conditions.

I am satisfied that these results are real and repeatable and, furthermore, have implications for birders and other nature observers observing wildlife from hides or simple observing stations, where substantial light shade is provided by the structure. Under these conditions, a larger aperture binocular should have a noticeable advantage over smaller instruments, no matter how well made it is.

A Delicate Flower

The Leica Trinovid BCA 8 x 20(right) must be handled with care owing to its small size.

Owing to its diminutive size, the Leica must be handled with considerably more care than the larger Zeiss. No less than four times in as many weeks I have almost dropped the instrument while taking it out of its case! As you can imagine, these incidents were the cause of considerable anxiety on my part and is due to the extremely small size of the folded instrument in my hands. As a result, I have to take extra care removing it and will now only do so at a table or on a couch. Whenever I deploy it, I immediately put the strap round by neck and keep it there until I’m done with it.

That said, I continue to be deeply impressed with the Trinovid’s excellent optical quality. This binocular has truly exceptional control of internal reflections and glare; better than any of my other instruments. Indeed, I have since learned that Leica is a world leader in suppressing unwanted light. After dark on March 1 2020, immediately after a heavy shower of sleet, hail and high winds, the sky cleared briefly in the mid-evening, when a beautiful crescent Moon hung majestically, low in the western sky and just above the tops of the conifer trees where the corbies roost. The Pleiades was located nearby, up and to the right of the crescent, making the apparition a particularly memorable one. I took the opportunity to compare and contrast the images seen through the Zeiss Terra and the Leica Trinovid, noting contrast, stray light levels and image sharpness. Though both instruments served up excellent results with wonderful earthshine on display from its dark hemisphere, the clear winner on this target was the Leica. The bright crescent Moon was more starkly presented in the Leica with almost zero evidence of internal reflections and nary a sign of even the weakest diffraction spike across the field(a common phenomenon in roof prism binos). The Zeiss showed a stronger diffraction spike, made more obvious only by the sheer perfection of the Leica,  and a tad lower contrast in comparison; certainly never enough to induce alarm by my standards, but enough to show that it was nonetheless superior to the Zeiss in this regard.

Contemplating a March Supermoon

A bright full Moon rising in the east at 6.17pm on the evening of March 8 2020.

The full Moon of March 8 2020 rose early in the evening, and as blue sky gave way to twilight, proper darkness finally set in after 7pm local time. I ventured out with my 8 x 25 pocket glass to observe its steely grey countenance. On this evening, where clear spells were interspersed with frequent heavy wintry showers, the brilliant Moon looked stunning in the little pocket binocular, navigating its way through patchy clouds and creating spectacular light shows as it did.

Presenting itself a little bigger and brighter than normal, this so-called Supermoon arises from its slightly elliptical orbit, which, every now and then, carries it closer to our planet than normal. With such a big, bright orb as this, it’s easy for the imagination to run amok. Tonight I saw it as one enormous canvass of sorts, or maybe some gigantic work of plaster of Paris adorned with God’s footprints!

As I relaxed to take in the naked eye view for a few moments, I noted that not so far away from big, bright Luna, there appeared a few faint stars, perhaps of the third magnitude, winking in and out of view as the rainclouds marched their way eastward across the sky. Now the Moon, I thought, is usally about magnitude -12.7 and with its closer approach it might well have reached -13 or thereabouts. So, my average eyes could make out stars that were about 16 magnitudes fainter than the Supermoon. A little math shows that the brightness differential between these faint naked eye stars and the Moon is of the order of 2.5^16 which is ~2,300,000.

Wow! What an amazing dynamic range the human eye possesses!

Recalling some technical details from my amateur photography days, that amounts to about 21 photographic stops! Then I found out that the dynamic range of the best digital cameras was only about 15 stops or so!

And did you know that the human eye can detect a single photon of visible light with an energy of the order of 10^-19 Joules. That’s 10 bilion billionths of a Joule!

“We may be small and insignificant in the scheme of things,” I thought, as I continued to admire a few minutes of a bright Moonlit sky, but, nevertheless, our Creator packed us full of technological wonders!

Great are the works of the Lord;
    they are pondered by all who delight in them.

Psalm 111:2

Drawn to the Light of the Great Outdoors

The River Endrick walk, Fintry.

With the days lengthening rapidly in March, the quality of light upon the landscape continues to improve, making glassing with the pocket binocular more productive and worthwhile. The strengthening sunlight illumines the hills, the fields, the trees, the rivers and streams, making anything with colour stand out with greater urgency. The trees are well on their way to shooting new leaves and the thorny gorse bushes have already begun to flower in their radiant yellow hues. With the improving strength and quality of sunlight, the performance of good quality pocket glasses become ever more apparent, allowing one to image targets in the field with breathtaking clarity. And what a beautiful world our Lord created for us, with its mindboggling complexity that just cries out to be explored by the naked eye and with quality tools that greatly extend our vision.

Beautiful, delicate gorse flowers.

Fear of the COVID-19 virus pandemic seems to be spreading faster than the virus itself. But I refuse to be inhibited by it. The human body is well designed to cope with viral infections but there are ways to boost the immune system by simple lifestyle changes. Walking in the great outdoors provides the necessary exercise to keep your cardiovascular system in tip-top condition. The virus can only survive a few hours in the open air, making it very unlikely to cause infection in this environment, especially if you keep away from crowds.

Gazing up into a great, old conifer tree with a bright blue-sky background can induce deep feelings of joy.

Sunlight too helps de-activate this pathogen by denaturing its protein coat,  as well as having a proven ability to stumulate the human immune system. Drinking plenty of pure, fresh water and including a wide variety of nutritious fruits and vegetables in your regular diet also helps your body fight infection. Some dietary supplements, including sulphur-rich garlic and N-Acetyl Cysteine(NAC) will also help your body cope better should you become infected. Temperance in alcohol consumption is always advisable too. Having said all that, few people appreciate the power of prayer to positively impact the immune system. Pray for strength, for endurance and for wisdom. As the Psalmist declared long ago:

Whoever dwells in the shelter of the Most High
    will rest in the shadow of the Almighty.

I will say of the Lord, “He is my refuge and my fortress,
    my God, in whom I trust.”

Surely he will save you
from the fowler’s snare
and from the deadly pestilence.
He will cover you with his feathers,
and under his wings you will find refuge;
his faithfulness will be your shield and rampart.
You will not fear the terror of night,
nor the arrow that flies by day,
nor the pestilence that stalks in the darkness,
nor the plague that destroys at midday.
A thousand may fall at your side,
ten thousand at your right hand,
but it will not come near you.

                                                     Psalm 91:1-7

Bidding Farewell to Old Friends

The evening of March 15 2020 proved to be cool, calm and mostly clear, so wrapping up warm after supper, I ventured out with my trusty 8 x 25 pocket glass, when I was immediately greeted by a sky full of stars! Brilliant Venus shone in the west with an intensity I had not encountered in many years. Like some great lighthouse in the heavens, it was bright enough to cast shadows of some of the more delicate tree branches on my backgarden lawn! Needless to say that the apparition was quite surreal!

By now, mighty Orion had past the meridian and was sinking towards the western horizon. But I was glad to see that big, orange Betelgeuse, which had spent a few months diminishing in brightness had, by now, regained much of its former glory. The little binocular beautifully framed the pure white stars of the Hunter’s belt, as well as showing up many fainter members of Collinder 70. And lower down, the Great Nebula in the Swordhandle was still presenting its visual magic with wonderful clarity. Ahead of Orion and even lower down in the western sky lay Taurus, with the refulgent stars of the Pleiades and Hyades still presenting well in the pocket glass. High above them I saw Auriga the Charioteer, also remaining well placed to glass its trio of ghostly Messier open clusters – M37, M38 and M36 – arranged nearly in a line from east to west, respectively, and almost fitting in the same binocular field. You can find them for yourself by taking a look at the star chart on page 89 of our guide book.

By this time of year, brilliant Perseus and Cassiopeia had wheeled their way far off to the north. But I was still able to get a reasonable view of the Double Cluster, though it couldn’t hold a candle to its glory days during the height of winter, when it was much higher in the sky. The exceedingly rich constellation of Gemini lay on the meridian, with myriad faint Milky Way stars coursing through its confines, and followed fast on its heels by the large and domineering Leo. It was clear to me that the sky was announcing the imminent arrival of spring!

Although glassing the night sky with a small binocular always upwells deep feelings of joy, I felt somewhat melancholic on this occasion, as I knew that the brilliant stars of winter would gradually be lost in the strengthening twilight that attends the unstoppable march of the seasons. But as the old adage proclaims, “abscence makes the heart grow fonder.”

I will see them again next season, God willing.

Oot ‘n’ Aboot

The coronavirus pandemic has gripped the nations with fear. But unlike COVID-19, the fear virus is far more contagious. It fills the godless with dread, bringing their mortality and materialism into sharp focus. And while anyone can catch the coronavirus, most Bible-believing Christians across the globe are entirely immune to the fear virus. You see, we’re sealed by the Holy Spirit(the third person of the Trinity) and so do not let such issues worry or control us.

The boys are off school but their education must continue; indeed, the same is true for many of their peers, and so my days are now occupied offering free online tuition to many of my former students to keep them focused. Truth be told, I’ve never been busier!  I still  take time to enjoy the beauty of God’s created order, whether it be the rural landscape around me or the strarry heaven above. Heeding the guidelines issued by the government, our movements are more restricted than in normal life, but thankfully we can still go for walks once a day. And there’s always the back garden to enjoy.

The daffodil-lined walk along the Lade, Fintry.

On the afternoon of Friday, March 27, my eldest son and I decided to go on a different amble from the route we normally take. Called the Lade, after the old mill lade that once stood on the site, it runs parallel to the Endrick River, and provides many opportunities for glassing. As we walked along the narrow, muddy path, under woody glades, I remembered the many occasions I used to take my boys along its winding track, when they were much younger and much more naieve. We chuckled amongst ourselves as I  pointed out the old disused barn where ‘Wee Willy Winky’ lived, or the scary looking tree trunk shaped like a monster. The barn remains but the ‘monster’ tree trunk had all but been reclaimed by nature.  My son carried his 8 x 32 and I brought along my versatile 8 x 25. Even in heavily overcast skies, the light is now good and strong making a pocket binocular a great choice to bring along to enhance the naked eye experience.

Because the trees have not yet produced their leaves, the Lade offers many opportunities to look out across the Endrick Valley to the Campsie Fells beyond.

The Lade walk eventually brings us to Craigton Pond, providing a natural fresh-water habitat for wading birds and a good spot to spend an afternoon fishing for Roach, Perch, Carp and other bony fish during spring and late autumn. In summer, the entire pond becomes choked up with water lillies which renders fishing all but impossible. We found the pond to be a hive of activity for various species of duck, and being a novice birder, I always delight in being able to identify new varieties with my pocket glass. On this afternoon, I was able to positively identify the female Goosander(mergus mergander), with its fetching grey plumage covering much of her body, white neck, chocolate-brown crown and nape, and a very long and slender hook-tipped sawbill in striking vermillion. When I first glassed the bird, I was sure it wasn’t a duck, but as soon as we got home, my good old RSPB guidebook informed me otherwise.

A good birding and fishing spot; Craigton Pond, Fintry.

Nature is such a treasure to be revered certainly; an endless wellspring of divine revelation, but it is not be worshipped like the New Agers and Extinction Rebellion fraternity seem to do. I suppose this modern nature worship got a big boost from the influential writings of the Dutch philosopher, Baruch Spinoza(1632-77), who conceived the Godhead as the entire material cosmos with its physical laws comprising the Divine essence. But though a Jew, Spinoza was barely a Jew at all. He completely rejected the Judeo-Christian concept of God as existing eternally beyond nature. Had he spent more time studying the printed words of the Torah – rather than the white spaces surrounding them,  Spinoza might well have formed an alternate opinion. In fact, the gods of all the eastern religions hold to something similar to Spinoza’s pantheism. To the Biblical God, pantheism is a fabrication; an idea of purely human construction; just another idol, if you will.

An Encounter with a Crescent Moon & Venus

Around 8pm on the evening of Saturday March 28 2020, on the eve of the return of British Summer Time(BST), I ventured outside to examine the progress of a clearing sky, and though some large cloud banks were still present, I spied a beautiful crescent Moon and a brilliant planet Venus less than seven degrees apart,  low down in the western sky.  How did I come on seven degrees you might legitimately ask? I was just able to image both objects in the same portal served up by my Zeiss Terra pocket glass, which offers up a true field of 6.8 angular degrees. The crescent Moon in March is one of the best times of the year to witness earthshine, where the lunar darkside is easily made out and breathtaking to behold in the pocket glass. I was struck by its haunting serenity, faithfully beaming its silvery rays upon us; a reminder that nature in all its grandeur dances to a different drum to anything in the human world; a temporary panacea from the trouble of our times.

A Gorgeous Sunset & Splendid Binocular Vignette

Sunset, Isle of Lewis, March 30 2020. Image credit: Gavin Porter.

Amid all the chaos wreaked by the COVID-19 pandemic, there are splendid moments of calm.

The evening of Monday March 30 2020 proved to be especially lovely in this regard. There was a gorgeous sunset this evening, with nary a trace of wind. It was more ruddy than usual owing to a greater amount of dust in the air from the prolonged dry spell we are currently experiencing in Scotland. An acquaintance of mine, Gavin, based on the picturesque Isle of Lewis in the Outer Hebrides, captured a beautiful sunset(see above) and kindly shared it with me. Coincidentally, I was also outside enjoying the same sunset but was even more captivated by the sight of a late crescent Moon and Venus(below) shining brightly in a clear, tranquil sky.

A bright crescent Moon and Venus (lower right). 8.46pm Monday March 30 2020.

On such an occasion I thought it fitting to bring out my little Leica Trinovid BCA 8 x 20, which produces especially beautiful images of the Moon, owing to its razor sharp optics and superlative suppression of glare. I was not disappointed! While it did show the Moon in all its glory with its prominent earthshine, I was even more thrilled to discover that the planet Venus was enjoying a close encounter with the Pleiades. Indeed, the Leica pocket glass captured both objects easily within the same field of view. I made a little sketch in my notebook to commemorate the apparition.

The Pleiades & Venus as captured by the Leica Trinovid 8 x 20 pocket glass.

The tiny, precision pocket glass that is the Leica Trinovid would make an excellent optical tool for keen photographers and portrait painters alike, as it produces exquisitely fine vignettes of the Creation. What it lacks in sheer aperture, it more than makes up for in the stunning clarity of its state-of-the-art optics.

A little bundle of joy: the Leica Trinovid BCA 8 x 20.

Tonight’s apparition in the western sky can be enjoyed by anyone, whether they live in the city or the country. So if you’ve got a clear sky, why not go out and have a look. It is sure to lift your spirits!

Showing the fruits of the Spirit during Lockdown

Bright April days trigger plants to shoot green leaves and flowers.

April is a month when the Creation goes into over-drive, especially if the Sun comes out to play, and, in this capacity, we have been blessed with a good run of fair and warm weather. Suddenly, the buds on the trees mature and young leaves appear. Early spring flowers burst into bloom, the grass is growing in the fields and the newly arrived lambs in the farmsteads ’round the estate are thriving. But there are always dangers posed to these young creatures. On one afternoon, I glassed a curious adult buzzard that had landed in  just a few yards away from a resting lamb, hoping that its mother would make a mistake and move too far away. Luckily, the buzzard got spooked and flew off, perching in a strong branch of an old oak tree, where it kept a keen eye on its potential prey. Losing a few lambs to raptors each year is the rule rather than the exception ’round these parts. I suppose all of God’s creatures need to eat.

While we are still in the grip of this viral pandemic, there are still many things to put a spring in our steps. When I see so many individuals confined to apartments around the world, especially in big towns and cities, with no gardens to roam in, I count my lucky stars that I have such a space to make the most of the lockdown. And there’s always plenty to see and do; the vegetables have been planted, a new fence has been laid, and another one painted. The trees around its border have been trimmed to let in as much light in the evenings. My neighbours are busy doing up their own gardens, and though we still have to practice social distancing to curb the spread of the pathogen, we nonetheless enjoy some lively banter across fences.

The great reduction in human nocturnal activity has paid unexpected dividends for stargazing too. ‘Glasglow’ is now much less conspicuous looking southward after dark, and moonless nights become even more spectacular to explore with a pocket binocular. Venus and the Pleiades have almost locked horns now for some days, but as we approach the Easter weekend, they are slowly inching apart.

Because of their close proximity, the corbies that roost in the conifer trees to the west of the house are fascinating to watch with my little 8 x 20 and 8 x 25 glasses. Though they make an awful racket flying to and fro from their nests, I enjoy watching their antics as their chicks hatch.

Much to my surprise- remember I’m not much of a birder – my pocket glass focused in on some high-flying birds in the sky above the house on the afternoon of  Maundy Thursday, April 9. Though it can prove difficult to identify species at distances of a few hundred yards, I was amazed to discover that they were most likely swallows that had returned from southerly climes to spend the summer in Britain. The pocket glass allowed me to see their forked tail and a lucky glimpse of one such bird that came closer than the rest revealed its black and white plumage. But what really gave them away was their very distinctive high-pitched ‘tswit,’ which fired off a very old memory trace in my mind hearkening back to my youth.

Unfortunately, there will be no worship in our local church this Easter Day because of the government-imposed shutdowns, but we can still link up via social media like Zoom, Facetime etc. And while our civic freedoms are still greatly restricted, we still have great freedom in Christ, who continues to shower us with the wholesome fruits of a believing heart:

But the fruit of the Spirit is love, joy, peace, forbearance, kindness, goodness, faithfulness,  gentleness and self-control. Against such things there is no law.

Galatians 5:22-23

Things to be Grateful For

I find it ironic in the extreme that ever since the lock down began some five weeks back, the weather here in central Scotland has been very pleasant, with long sunny days, hardly a drop of rain and clear skies almost every night. Indeed, I can’t remember the last time we’ve enjoyed such a long run of fair weather. The Creator remains gracious even in these troubling times!

Indeed, I have managed to observe my tally of spring double stars and deep sky objects much earlier in the season than usual and all my Newtonian reflecting telescopes have been employed to the full. The trees are now covered in fresh young leaves that are a delight to glass with my pocket binoculars. The evening sky just after sunset in these last days of April 2020 have been particularly awe-inspiring with Venus now at its brightest and a crescent Moon nearby in the western sky. On the evenings of April 25 and April 26, I took a few photos of the apparition with my iphone. And while Venus and the Moon were much too far apart to capture in my Zeiss Terra pocket with its 6.8 degree field, on the evening of April 25 they were just close enough to sight in the same field of view at ’round about the same time(see below) on the following evening( April 26).

The crescent Moon and Venus(at top) right as it appeared after sunset on the evening of April 25 2020.

The Venus & Crescent Moon apparition as it appeared on the evening of April 26 2020.

Such lunar and planetary conjunctions are rare but they certainly help raise the spirits in these troubling times.

When proper darkness falls on the landscape, I’ve been visiting a few optical double stars around the night sky that are well seen in the pocket binocular, and I intend to present a list of such objects in a later episode of this blog. So stay tuned!

The Terra Pocket Now Moved to China?

The original Zeiss Terra pocket glasses were made in Japan (Katsuma Optical) under Zeiss supervision.

I recently received a message from a chap named Olly, in which he stated that his newly acquired Zeiss Terra pocket glass now had ‘China’ printed both on the binocular and on the box it came with. From their launch several years back, I understood that these pocket glasses were the exception to the rest of the Terra line, where all of the larger models were being manufactured in China. I asked him if he would send me on a photo of his new binos showing the Chinese origin, but he didn’t respond. Thus, I contacted Zeiss sports optics directly to find out if in fact it was true. Alas I have yet to receive a reply! My next line of investigation took me to two UK suppliers of these pocket binoculars and thankfully, they were quick to reply. I can confirm that Olly’s news is true; the Zeiss Terra pocket glasses, like the larger Terrra models, are now manufactured in China, but still carry that valuable Zeiss design. I also note that the retail price for these units remains unchanged.

What will the change of country of manufacture do to these superlative little pocket glasses? Realistically, probably nothing, save perhaps for slightly inferior quality control. Would I personally be worried about that? Honestly, no! I have several binos that offer excellent performance and all are assembled in China, so I’m guessing that the consumer will not notice the slightest bit of difference between the Japan-made model and its newer Chinese made counterpart. Of course, I would love to hear from anyone who has experienced anything out of the ordinary with respect to these newer Terra pockets, or if they have had a chance to test the older and newer models in a side-by-side comparison.

For journalistic purposes, I’ve made a note of this change in a new postscriptum on my original review of the Zeiss Terra ED 8 x 25, which you can see here.

Cicely’s Way

Cicely’s Way, Fintry.

May has arrived at last, and the idyllic weather continues apace. The landscape is bathed in life-giving sunshine, and the wildlife is thriving. A couple of days of rain has soaked the ground, helping to keep the gardens looking vibrant and there is plenty of fresh green grass for the lambs and calves coming into the world. Conditions are also perfect for taking a pocket binocular along for a good walk. As I’ve touched on earlier, Fintry is blessed by having a number of great walks and the most recent one created is Cicely’s Way, named in honour of an elderly lady in our village, who has dedicated much of her free time over the years to planting flowers on the main road of our village and decorating the window ledges of our village hall, keeping it looking beautiful. Indeed, Fintry has won many prizes over the years for its outstanding natural beauty and on one occasion it even won first place the prestigious Britain in Bloom award.

Cicely’s Way has extensive hedgerows, which is great for glassing small birds that frequent the branches; robins, finches, chaffinches and even the odd song thrush hunting for worms and insects.

The river walkway has now become crowded with bunny rabbits which are excellent binocular targets. But what I most enjoy is the vibrant colours of young, tender leaves that have a beautiful translucent quality during Spring. In the evenings, as the Sun loses altitude, it shines its golden rays right through them and I enjoy glassing their intricate structures as they thrive in the warm weather. Slowly they will become darker in tone and that magic light green hue will disappear as they mature and darken as summer arrives.

With the days growing ever longer, the nights become progressively shorter and soon the summer twilight will succeed in banishing true darkness for a season. But what is lost in night time observing is more than made up for in daytime glassing activities. This year, we have booked a lovely cottage on the outside of Gairloch, a small picturesque village way up in the northwest Scottish Highlands on the shores of Loch Gairloch, Wester Ross. Hopefully, we will get to enjoy that holiday which will occur in early July, when the days will be very long and I can glass to my heart’s content!

The village of Gairloch, Scottish Northwest Highlands. Image credit: Wikipedia.

The new origin of the Zeiss Terra pocket glasses is now being debated. Zeiss did finally get back to me, stating that these binoculars are still being manufactured in Japan, although a number of individuals have now come forward claiming that they are now being made in China – and with photographic evidence to boot. Such a question doesn’t really bother me but I guess it’s important to establish the truth in any matter. Time will tell!

At home in the great outdoors.

That having been said, I am using the little 8 x 25  Terra more than ever. Its super light weight, good ergonomic design and excellent weatherproof optics makes me reach for it time and time again.  And I look forward to bringing it to other wild places once the COVID-19 lockdown measures have been relaxed.

Cruising the Early Summer Milky Way

The extraordinarily rich constellation of Cygnus reaches a decent height above the eastern horizon in the wee small hours of mid-May. See page 137 of our guide book.

From mid-May onwards into the summer, the nights grow painfully short, making astronomy more and more challenging as the solstice approaches. But that being said, in the wee small hours after midnight, the majestic constellation of Cygnus reaches a good height over the eastern hills across the Endrick Valley from our home. And even with a low lying waning Gibbous Moon in the sky, that part of the sky remains quite dark, making it worthwhile to scan with a small pocket glass. Although I have by now completed nearly all my telescopic deep sky observing until the return of dark skies again in August, and while Cygnus is much better positioned in the later months of the year, it is still a joyous experience to explore the rich bounty of Milky Way stars coursing through this great northern constellation.

Brilliant white Deneb, creamy white Sadr and the lovely orange Albireo trace out a  great line through which the pocket glass can soak up hundreds of fainter stars. Moving the glass between Deneb and Delta Cygni, the little Zeiss 8 x 25 does a sterling job of resolving the much celebrated o^1 Cygni, with its beautiful colour contrast pairing of stars; orange & turquoise. Even with such a small instrument, it is possible to gain a sense of the immensity of the stellar Universe beyond our solar system with many of the stars visible in the generous 6.8 degree field being located hundreds or even thousands of light years away.

So numerous are the stars, so magnificently they shine through the darkness

Faithful comforters, fountains of radiant beauty,

How great is our God who fashioned them all with His hands!

And though uncountable by mortal human minds, each one is intimately known to Him who gives them light and life.

The Psalmist of old declares it:

He counts the number of the stars;
He calls them all by name.
Great is our Lord, and mighty in power;
His understanding is infinite.

Psalm 147:4-5

Long Range Microscope

A flowering Rhododendron.

With daylight now being strong and long-lived, the pocket binocular comes into its own as a long-range microscope, allowing one to study close-up views of the creation in extraordinary detail. And though I am possession of two fine pocket glasses, it is the larger Zeiss Terra 8 x 25 that is now pulling well ahead in terms of frequency of use. Because it is larger and easier to use than the Leica Trinovid, and owing to its rugged, fully waterproof casing, it’s simply the best choice in most situations. This is particularly the case when close-up views of nature are required. The Zeiss has a much shorter close focus and wider field of view than the Trinovid, making observations of rocks, insects, flowers, tree bark and leaves that little bit more engaging.

Close-up glassing of nature is not for everyone however. This is because zooming in at something at such close range( two metres and under) can be a bit discombobulating for some observers who struggle to get their eyes comfortably placed behind the eyepieces. What happens here is that your eye pupils have to move together more in order to properly image the target, but the situation is considerably improved by pushing the barrels of the binocular closer together to reduce the IPD. I discovered this trick quite quickly and naturally in the field, and it works well for many roof prism binoculars. Of course, there are other types of binocular that are even better suited to close up viewing of nature, particularly the economically-priced reverse porro prism models being offered by a number of optical firms. But what you gain in close focus with these binoculars, you lose in portability, especially pocket portability.

Solar Peculiarities

A babbling brook bathed in warm sunshine; Culcreuch Castle Estate.

God continues to bless our weather during the continued lock-down here in Scotland. The brilliant Sun at the centre of our solar system provides the light and warmth that makes succulent strawberries grow in our greenhouse and fresh rocket for our salads. The apple blossoms are ablaze with colour  and the mild winter we have come out of will ensure an abundant harvest in the autumn.

How much we take for granted the life-giving rays of the Sun! Indeed, as astrophysical science progresses, we are learning that it’s not only the most stable star yet identified in the starry heaven, it is also peculiarly quiescent compared with other sun-like stars in the solar neighbourhood. Indeed a recent survey of 369 sun-like stars showed that their activity is considerably higher(about five fold on average) than our own Sun, which is quite unexpected given what we currently understand about stellar astrophysics. If this is generally true then it might spell more bad news for those who continue to hold out for finding another habitable planet out there in deep space. Indeed, our Sun varies its luminosity by only 0.07 per cent in any one twenty four hour period!

For over a year now, I’ve been monitoring the Sun with a few of my binoculars, but most especially my trusty Pentax PCF 20 x 60, which produces a decent image scale to monitor sunspot activity, but I have also constructed neat little white-light solar filters for my 8 x 25 pocket glass, which I also find fun to use on occasion. And though I certainly have not monitored the Sun every day because of other commitments, my log books show that it has been over a year since I recorded my last sunspot on the solar photosphere. But recent professional studies show that the Sun in 2019, and thus far in 2020, has shown no sunspots, however small, for most of this time, which has prompted some astronomers to think that it may be entering an unusually deep minimum and could even be commencing a lockdown of its own. If that’s the case, past history suggests it may not bode well for planet Earth, since prolonged periods of solar inactivity has been linked to higher cosmic ray fluxes in Earth’s upper atmosphere which triggers more electrical storms, as well as significant global cooling. Maybe this is another sign in the heavens, just like mighty Betelgeuse exhibited just a few short months ago? Let us pray that the Sun will soon be roused from its unusually long slumber!

Exploring the Twilight

Strong twilight as captured at 11 pm local time on the evening of May 24 2020.

As May comes to an end, so too does the summer twilight grow ever longer. I like to take the time to venture out after sunset and watch the first appearing of the stars, as our great solar furnace makes its way further below the northwestern horizon. Twilight can be a magical time for quiet contemplation and prayer. The noisy Corbies settle down to sleep, and the gentle evening winds peter out, leaving only the faint, babbling sound of the nearby river to fill the air.

Brilliant Vega is invariably the first to appear to the naked eye high up in the east, while yellow-orange Arcturus can be spotted just a few minutes later, rapidly approaching the meridian. Low in the north the lovely yellow light of Capella can be made out and waiting a little while longer, the soft white light of Deneb over in Cygnus peeps out to say hello. By then the sky has become sufficiently dark to reveal the magnificent asterism of the Ploughshare dominating the zenith.

During these times, I can enjoy prolonged periods with the pocket glass, capturing picturesque scenes of faint starlight winking into view over the silhouetted branches of trees. More often than not, those same scenes are temporarily interrupted by the appearance of hunting bats, frantically flitting through the field of view, as they hone in on their insect prey. Many a late evening during June and July can be enjoyed in much the same way. Still, no two twilit nights are ever quite the same. This evening, for example, I was lucky enough to spy a beautiful, slender lunar crescent very close to the northwest horizon and almost hidden by a thin veil of wispy cloud at 10.15 pm. And if that were not exciting enough, I was also most fortunate to witness a bright fireball rushing across the sky overhead, moving roughly from north to south at five minutes to 11. Indeed, it was probably one the brightest fireballs I have ever witnessed in such strong twilight!

Such are the surprises that attend an evening out with a pocket glass. And who knows how another day in May will end?

 

To be Continued………………………….

 

 

De Fideli.

Product Review: Zeiss Terra ED 8 x 25 Pocket Binocular.

The Zeiss Terra ED 8 x 25: a noble gesture from a market-leading optics firm.

October 1 2019

Preamble;

Review A

Review B

 Review C(verified purchaser):

Although I read glowing reports for these pocket Zeiss Terra ED 8×25 light carry binoculars, my previous 4 month ownership of the Swaro CL 8X25 pockets had tempered my expectations. However, I found these small glassing gems to perform optically and ergonomically within 95% of the venerable and well built CL’s (at 1\3 the price)! They, just as the CL, have handling and comfort limitations compared to compact or full size binoculars. But for quick trip non-intrusive viewing, ease of portability and very accurate powered views, these little pockets are hard to beat. Overall, they possess very nice ergonomics, have natural color presentation, crystalline resolution that is real sharp and bright, with very good contrast views. Their FOV (field of view), whose sweet spot extends to within 10% of their wide 357ft limit, has a comfortable and stereoptic DOF (depth of field) . Hinge tensions are perfect, and the focuser is fast, going from close focus (mine’s about 5ft) CW to infinity in just 1.25 turns. Eye cup adjustments lock fully in (for eye glass wearers) and fully out (non-eye glass wearers). My vision is 20\15 and with the very comfortable eye cups fully extended and resting on my brow, I can align the small EP (exit pupil=3.1) with my pupils, gaining a full unobstructed sigh picture! With its ED glass, CA (chromatic aberrations) is well controlled and I find day light\low light viewing to be bright, natural and enjoyable! Diopter is set on the front dial (for the right barrel) and has enough resistance to stay put. Made in Japan for Zeiss, they offer a lot of features and performance at a great value point. These will make great travel companions and will be back-ups for my full sized field excursion instruments!

Review D(verified purchaser):

I also read about these on an astronomy forum, where I got the “use” info below, but not the specs.
Buy these now. A best buy. Here’s why:
1. Zeiss is a world class optics company. So is Swarovski.
Compare this Zeiss Terra ED 8×25 to the world-class Swarovski 8×25 at $819 on Amazon (list price is even higher). This will show you
a) specs are same: field of view (6.8˚),
brightness (14.1 vs 14.2),
weight (11 vs 12 oz),
eye relief (16 vs 17mm), and
size in inches
b) specs favor Swaro: water resistant to 4 meters (vs 1 meter for Zeiss)
c) specs favor Zeiss: close focus 6.2ft (vs 14.2 for Swaro),
operating temperature -20 to 144˚ (vs -13 to 131 for Swaro)
d) use favors Swaro: view is said to be more comfortable to look at, ergonomically
focus has lighter touch, for those who like that
e) use favors Zeiss: view is more crisp, contrasty (Swaro view is said to be softer, more milky)
focus has firmer touch, for those who like that
f) price favors Zeiss: $293 (vs $819 for Swaro)2. Compare them to other Zeiss binos from the SAME series – Zeiss Terra ED.
– 8×25, 10×25 are made in Japan
– 8×25, 10×25 are getting great reviews, for small binos
– all larger Terra ED models are made in China
– all larger models are getting panned for poor optics and build quality
I think everybody is well aware that China optics and build quality are inferior (so far) to those from the US, Japan, Taiwan, Germany, Austria, etc.So this 8×25 model is unusual. Superior optics and build are normal for Zeiss, except for their Chinese built Terra ED line.
Luckily, the 8×25 model is made in Japan with Zeiss design. This results in typical world class Zeiss quality.What is hard to understand is how Zeiss makes a $293 optic that arguably outperforms an $819 Swarovski.For bino newbies looking at 10×25, remember: the 10×25 will have a smaller exit pupil, so your views may black out more. Also, a 10x is way harder to hold steady and actually see than an 8x. So, even though you think you want 10x, you probably really want 8×25. With the 8×25, you’ll actually see and enjoy the view more.………………………………………………………………………………………………………………………………..

What you get:

The Zeiss Terra ED 8 x 25 pocket binocular kit.

The Zeiss Terra pocket arrived double-boxed. After opening the outer packaging, the binocular kit was housed inside a very nicely presented box with a very fetching design which folds open to reveal the contents. Unlike other products I’ve received in the past, the Zeiss box has depicted on the inside, a colourful alpine scene with majestic mountain peaks soaring high above a beautiful river valley. Perhaps the team at Zeiss intended the user to explore such landscapes? Whatever the reasoning behind it, it was certainly a pleasant touch.

With Zeiss, even the packaging is premium.

Unlike customers who bought the Zeiss pocket binocular when it was first launched just a few years ago, I was relieved to see that the instrument was housed inside a small clamshell case with a magnetic latch carrying the blue & white Zeiss logo.The box also contained a lanyard, operating instructions and a lens cleaning cloth. I was surprised that the binocular itself came neither with eyepiece or objective lens caps, but I suppose they are not really necessary, as the case very effectively protects the instrument from dust and moisture.

The box has the serial number on the side, which is needed to register the product on the Zeiss sports optics website.  On another side of the box, the detailed specifications of both the 8 x 25 and 10 x 25 models are presented; another nice touch.

The binocular was housed inside the clamshell and was pristine, with no dust on the lenses, or gunk on the interior of the barrels. From the moment I prized the neatly folded instrument from its case, I was impressed. The frame is composed of a fibre-glass like polymer, with a fetching black, grey and blue livery. The sides of the binocular have a rubberised exterior making it easy to grip well while in use. The double-hinges were rigid and hold their positions solidly once the correct inter-pupillary distance is chosen for your eyes. The optics are hermetically sealed, nitrogen purged and had immaculately finished anti-reflection coatings on both the ocular and objective lenses. They are also treated with a Zeiss’ proprietary hydrophobic coating that encourages any moisture and grime that gathers on the lenses to fall off, rather than accumulating on the surfaces. The instrument is guaranteed to operate flawlessly over a very impressive temperature range: -20C to +63C, so covering almost any environment it is likely to find itself in.

The binocular is water resistant, but to what degree remained a bit of a mystery owing to the rather odd way in which Zeiss chose to present it: 100mbar.

You what mate?

Thankfully, some physics knowledge helps to clarify the reference to water pressure.

P = Rho x g x h, where P is the water pressure, Rho is the density of water, g is the acceleration due to gravity and h is the depth in metres. Rearranging to find h gives;

h = P/ (g x Rho) = 10^4/ (10 x 10^3) = 1m

Knowledge is power lol!

So, not as waterproof as a Swarovski pocket binocular(I think it’s 4m) but adequate for most purposes.

Fully folded down, the Zeiss Terra pocket is about 70mm wide and 110mm long. The oversized barrels make the Zeiss a wee bit taller when placed on its side in comparison to a classic pocket instrument, like my lovely little Opticron Aspheric LE;

The Zeiss Terra Pocket(right) is a little wider and taller than the more conventional Opticron Aspheric(left).

The Terra weighs in at 310g, so about 40 grams lighter than the Swarovski-made counterpart. Lighter isn’t necessarily better however, as some individuals find holding such light glasses problematical. But once unfolded, the significantly wider barrels more than make up for its low mass, as I shall explain more fully a little later in the review.

The eyecups look a bit suspect, but once you begin rotating them, they work really well. They have no indents but do have ample friction. There are only two positions; fully retracted or fully extended. You know you’ve reached either situation by hearing their clicking into place. They are very solid and hold their positions superbly. Eye relief is 16mm and I was able to enjoy the full field with eye glasses on or without. Placing your eye on the eyecups is very comfortable, with their soft, rubberised overcoat and the large field lenses makes for very easy centring of your eye sockets along the line of sight of the optical train.

The dioptre(+/- 3) setting lies at the other end of the bridge(near the objectives), which initially presented some problems for me, as it is rather stiff and difficult to get going, but once you’re done you’re done! The focusing wheel is centrally located and is reassuringly large and easy to grip, even with gloves on. It moves very well, with the perfect amount of tension. Motions run smoothly, with little in the way of play or backlash when rotated either clockwise or anti-clockwise. The focuser requires one and a half full rotations to go from one end of its focus travel to another.

The Zeiss Terra ED 8 x 25 has a large, centrally placed focuser. The right-eye dioptre ring is located at the other end of the instrument, near the objective lenses.

The objective lenses are very deeply recessed, more so than on many other pocket binoculars I’ve used. This affords the 25mm objective lenses greater protection against aeolian-borne dust and also serves as a first-line defence against glare. Cool!

As the other reviewers showcased earlier, the Zeiss Terra pocket binoculars are manufactured in Japan, with the larger models originating in China under Zeiss supervision. You can see that quite clearly by examining the under belly of the instrument:

The underside of the binocular reveals its country of manufacture: Japan.

That said, and contrary to what the other reviewers have asserted, I don’t fully subscribe to the notion that all Chinese-made binoculars are inferior to those produced in Europe or Japan, as I shall elaborate on later.

All in all, it’s pretty obvious that a great deal of sound engineering was put into these pint-sized field glasses.

Handling: The Zeiss pocket is supremely comfortable to use, the slightly larger frame fitting comfortably in my hands. Indeed, with its wide field of view and thicker barrels, it feels like you’re peering through a larger instrument. The big eye lenses make it easy to get the right eye placement with none of the blackouts I’ve experienced on a number of other pocket binoculars. Its light weight means that you can carry it round your neck for hours on end with no neck strain. Its easy to get both hands resting on the central bridge, using my little finger to engage with the focus wheel.

Optical Assessment:

Straight out of its case, the Zeiss Terra impressed. Looking at some tree trunks just beyond my back garden fence reaveled a wealth of high contrast detail. I was immediately taken aback with the expansive field of view; not only was it wide, but the image remained tack sharp across nearly all of the field. Images snapped to a very sharp focus and I experienced no trouble focusing from just a few yards away all the way out to some trees located hundreds of yards away. Glare suppression looked excellent, even when pointed at some backlit scenes strongly bathed in sunlight. It was immediately clear to me that I was looking through a very high quality optical instrument.

As I stated in earlier blogs, I don’t really consider the inclusion of low dispersion (ED) glass as necessary in a small binocular like this, but it’s a nice feature when presented as part of a larger, properly designed system. After all, and as several other reviewers pointed out, the Zeiss seemed quite comparable to arguably the most sought-after pocket binocular on the market; the venerable Swarovski CL pocket binocular. But what is not widely communicated is that the latter achieves all its optical excellence without using ED glass. That should send a powerful message to the gayponaut propagandists. No, its all about using great glass, great coatings and solid mechanical engineering. Alas, I was not able to compare this pocket binocular with the Swarovski, but the fact that the little Zeiss was often mentioned in the same company as it speaks volumes about its optical quality.

Further daylight tests showed that off-axis aberrations were very well controlled. Even at the edge of the field pin cushion distortion and field curvature were minimal. Looking straight up at a denuded tree branch against an overcast sky showed no colour fringing on axis but as the image was moved off axis, some slight secondary spectrum was noted. Overall, I was very impressed at the Zeiss’ optical quality; it really does exactly what it says on the tin!

A niggly moment: While the little Zeiss pocket binocular fits perfectly inside its small, clamshell case without the supplied neck strap attached, I found that the addition of the strap made it very difficult to get a snug fit. Wrapping the neck strap around the central bridge simply didn’t allow the case to close properly(the magnetic latch never stuck), but after several attempts experimenting with different approaches, I finally hit on a way to get the binocular with its strap on to fit the case. The trick involves wrapping the strap tightly around the ocular lenses.The latch sticks.  Problem solved!

More discriminating optical tests:

Flare & Glare assessment:

Even if the glass used in binoculars were mined from the asteroid belt, it counts for nothing if it can’t control light leaks. My initial daylight tests showed that glare and internal reflections were very well controlled in the little Zeiss binocular, but they can’t tell the whole story. So, I set up my iphone torch at its brightest setting in my living room and examined the focused images through  the Zeiss Terra, comparing its results with my Opticron Aspheric(a nice little performer) as well as my control binocular; the Barr & Stroud 8 x 42 Savannah, which has excellent control of stray light.

The results were very interesting. The Zeiss faired better than the Opticron, but not by much. However, it was not as good as the Savannah, which exhibits exceptional control of internal reflections even though it collects far more light than any pocket binocular.

Further testing of the binoculars on a bright street light revealed some additional information. Internal reflections were well suppressed in both the Zeiss and Opticron binoculars, but the Zeiss showed more prominent diffraction spikes. The Savannah control binocular, in comparison, proved superior to both pocket binoculars. It shows very little flaring and internal reflections and much better control of diffraction spikes.

And therein lies an instructive lesson. The Barr & Stroud Savannah 8 x 42 is fabricated in China yet shows exceptional control of glare and internal reflections. So, it’s not so much where a binocular is built that counts so much as how it is constructed.

An exceptional, Chinese-made binocular; the Barr & Stroud 8 x 42 Savannah wide angle 143m@1000m.

It is all the more remarkable, since the Savannah can be purchased for half the price of the diminutive Zeiss!

All in all, these tests showed that the Zeiss binocular is very well protected against stray light, glare and internal reflections and this goes a long way to explaining why the views through it are so compelling.

Collimation and Field of View Tests:

I checked the collimation of the barrels on the Zeiss by placing the instrument on a tall fence and aiming at a rooftop, checking that both the horizontal and vertical fields correlated with each other. They matched up very well.

Field of view is best assessed by turning the binocular on the stars. Accordingly, I aimed the Zeiss Terra at the two stars at the end of the handle of the Ploughshare, now low in the northern sky. The Zeiss was able to image both Mizar and Alkaid in the same field with a little bit to spare. These stars are separated by an angular distance of 6 degrees 40′ (or 6.66 degrees). This result was consistent with the specifications on the inside of the box; 6.8 angular degrees.

Further Observations:

Comparing the Opticron Aspheric to the Zeiss Terra in daylight, showed that both instruments were about equally matched in terms of sharpness( the aspherical oculars on the Opticron certainly help in this regard), but I could discern that the image was that little bit brighter in the Zeiss. Better coatings in the Zeiss binocular throughout the optical train give it the edge in this regard. Field of view was also much more expansive in the Zeiss( the Opticron has a true field of 5.2 degrees in comparison). Colours were also that little bit more vivid in the Zeiss pocket binocular, caused perhaps by its better contrast and superior control of chromatic aberration.

Close focus is very good. I measured the Zeiss Terra to have a minimum close focus distance of 1.4 metres, so this should be a great little instrument for use as a long distance microscope, to spy out insects, fungi, flowers, rocks and the endlessly fascinating complexities of tree trunks.

The eye lenses on the Zeiss Terra pocket binocular measure 18mm in diameter, the same as the Swarovski CL pocket. But they are still small in comparison to a larger format binocular like my 8 x 42.

But while the field of view is quite immersive in the Zeiss Terra, it lacks the majesty factor of a larger binocular, such as my Barr & Stroud 8 x 42 Savannah, with its whopping 8.2 degree true field and better eye relief. Larger binoculars are simply easier to engage with your eye sockets and are thus more comfortable to use than any pocket binocular on the market.

Performance under low light conditions easily show the limitations of the small objectives on the Zeiss Terra. At dusk, the 8 x 42 was vastly superior to the Zeiss, showing much brighter images, as expected. So, as good as the Zeiss pocket binocular is, it can’t defy the laws of physics.

A Walk by the River Bank

River Endrick, near my home.

One of the best reasons to own and use a pocket binocular, is that it encourages you to go outside and explore the landscape. They’re so light weight and handy that anyone can carry one. Sometimes I use the Opticron and at other times I like using the Zeiss. Their sharp, high-contrast optics deliver wonderful images of the Creation. For me, nature is life affirming; a profound source of revelation and illumination. Like a great Cathedral, it fills me with awe and wonder. The sound of the wind whistling through the trees, the babbling brook and the noisy chirps of small tree birds form part of a symphony paying homage to the One who fashioned it all. For some, the Darwinian, materialist lie has dulled or even extinguished the sense of wonder that is innately endowed to every child. Dead to the world, believing themselves to be highly evolved animals, they pose no meaningful questions and can give no meaningful answers to life’s biggest conundrums. As you think, so you are.

But it doesn’t have to be that way!

For me, being able to explore the wet and wild places with tiny optical aids is a source of unending joy. On sunny afternoons or early in the morning, I sometimes take myself off for a walk along the banks of the River Endrick which meanders its way through the beautiful valley in which I live. Stretches of shallow, fast-flowing water predominate but are also complemented by deeper pool and riffle sequences; favourite haunts of  Brown Trout, Perch and other course fish. Lanky Herons frequent these waters in search of fresh prey.  Bracken flourishes all along the river, and my pocket binocular allows me to study their shape and form in great detail. As summer gives way to autumn, their bright lorne hues transform into various shades of brown and tan. Spiders weave elaborate but deadly webs of silk with their spinnerets that sparkle and glisten in the morning sunlight, creating a wondrous decoration that I can experience up-close and personal with my long range microscope.

Towering trees soar into a blue sky by the banks of the Endrick.

Many species of tree grace the banks of the river; Ash, Silver Birch, Sycamore, Horse Chestnut and even the odd Oak. Thriving from frequent rain showers, their trunks are covered in lichens, moss and algae that reveal a wealth of intricate structure and a riot of colour that changes in accordance with the varying altitude of the Sun as it wheels across the sky. I especially delight in observing the colour of autumn leaves in bright sunlight, the ruby reds of anthocyanins and the yellow-orange hues of carotenoids. Every now and then, I watch as the fast-flowing water, dappling in weak autumn sunshine, ferries off fallen leaves, their destinies unknown. My pocket binocular shows me that every tree trunk is unique. Each tells its own story, visual scars of its past life.

On some stretches of the river bank, I can still find some late-flowering wild plants that delight the eyes with colour in unexpected ways. And as autumn continues its march towards winter, the thick brambles begin to yield their succulent fruit. What could me more pleasing and more natural than to feast on their nutritious berries?

An expected riot of autumn flowers observed along the river bank.

At some places along the river bank, there are expansive rocky stretches. And yet every stone you un-turn reveals even more of God’s Creation. A scurrying earwig, a wondrously armoured wood louse or a frolicking spider.The pocket binocular brings everything into stunning clarity. And though at first glance, each stone looks more or less the same, my little pocket spyglass shows that they too are all unique. Every crevice, every colourful grain is one of a kind.

A rocky stretch along the river bank.

This tiny corner of the world is ripe for exploration, with every day that passes presenting new adventures, new wonders to delight the eye. But so is yours!

Bird Watching with the Zeiss Terra Pocket Binocular:

Can good pocket binoculars be suitable for birdwatching?

Lots of birding websites don’t recommend using pocket binoculars for bird watching, citing their small fields of view and reduced comfort compared with larger binoculars as the most common reasons. Having used these small binoculars for a while now, I must say  that I respectfully disagree. The Opticron Aspheric has served as a good birding binocular for me, especially for quick looks at birds that visit our back garden table and the crows that nest in the conifer trees in the common ground beyond our back yard fence. Recently, a group of five magpies have taken up residence in the Rowan tree in our back yard. Each evening as darkness falls, they hunker down in the tree and don’t seem to be fazed by us turning on an outside light or noisy disturbances when it’s time to put the garbage out. During the day though, they are often seen chackering away at each other loudly(magpies don’t actually sing) as if to resolve some dispute among themselves. Further afield, there is a small pond just a few hundred yards away in the grounds of Culcreuch Castle, which attract quite a few varieties of water bird; swans, duck, water hens, heron and even the odd cormorant. Once I learned to use them properly, small binoculars like these have never presented much in the way of a problem for me.  And since the Zeiss Terra pockets have a nice wide field of 6.8 degrees, they have proven to be better suited than the Opticron in this regard because you can better track the motions of birds with a wider true field.

On the Zeiss Sports Optics website, under ‘usage’, they seem to be saying that the Terra pockets are less suitable for birding, but I wonder if this is merely a clever ploy to get folk to buy into their larger(and more expensive) models. If so, they’re lost on me. With their excellent optics and generous field of view right to the edge, they can and do serve as good birding glasses. Of course, you can only form your own opinions by actual field experience but you may discover that the little Terra is all you really need! Seen in this light, acquiring a Zeiss Terra pocket binocular can actually serve as a cost-saving measure that stops you haemorrhaging your hard-earned cash on ever bigger and more expensive models.

How About Astronomy?

A small binocular like this is not the best for exploring the night sky since its small objective lenses cannot gather enough light to really wow the observer. However, the Terra’s excellent performance both at the centre of the field and extending nearly all the way to the edges, as well as its wonderful contrast make star gazing a pleasant experience. Out here in the sticks, the sky is quite dark and rewarding, even when observed with such a small instrument. Its field of view is large enough to enjoy some of the showpieces of the sky like the Pleiades, the Hyades, and larger asterisms such as Melotte 20 in Perseus, which can be taken in with its generous field of view. Stars remain very tightly focused and pin sharp across the field. Later in the season, I look forward to exploring the winter constellation of Orion the Hunter, to seek out its magnificent nebula in his Sword Handle, as well as the many delightful clusters of stars that are framed within its borders.

On another autumnal evening, I was able to pick up the three Messier open clusters in Auriga, M34, the Messier galaxies, M81 and M82, the Andromeda Galaxy, the Double Cluster in Perseus, wide double stars like Mizar & Alcor and the Coathanger asterism in Vulpecula. Running the binocular through Cygnus and Cassiopeia will also reward dark-adapted eyes with innumerable faint stars, like fairy dust on black velvet. One delightful little project involves exploring the lovely colours of bright stars such as blue-white Vega and Sirius, creamy white Capella, brilliant white Rigel, orange Arcturus and fiery red Betelgeuse and Aldebaran.

Following the phases of the Moon can also be a rewarding and worthwhile pursuit, as the Terra’s above average glare and internal reflection control will ensure that you get nice crisp, contrasty images. Lunar eclipses can also be enjoyed. You might also like to try your hand at observing the beautiful light shows presented by clouds passing near the Moon on blustery evenings. The excellent contrast of the Terra will also allow you to see stars around the Moon which can be very arresting to observe. Capturing the bright Moon as it rises over man-made buildings will also delight the eye. Above all else, don’t let its small aperture deter you from exploring God’s wonderful creation, which fills the Universe with hope and light.

Final thoughts:

Terra: for exploring the Earth and beyond.

The Zeiss Terra ED 8 x 25 pocket binocular is a fine, high-quality optical instrument that is easy to use and transport. If taken care of, it will give you years of enjoyment where ever you wish to take it. As I said from the outset of this blog, I believe Zeiss did something very noble in bringing this little binocular to market at the price point they set. To be honest, and as others have quipped, they could well have stuck a ‘Victory’ label on it and no one would be any the wiser. Optically, Zeiss engineers have cut no corners to deliver an ergonomic, durable and optically sound instrument that will delight anyone who looks through it. I suspect that the Zeiss Terra pocket might be one of their best-selling products. It is even available on finance and buy-now-pay later schemes here in the UK, although I would strongly advise would-be buyers to save up and pay the price in full rather than incurring more debt, where you ultimately pay more. The Zeiss is expensive as small binoculars go, but I feel that it’s worth every penny, as for me at least, it has already given me countless hours of wonderful experiences. In the world of high-quality pocket binoculars, the Terra certainly stands out in a crowd. Highly recommended!

 

Thanks for reading.

 

Neil English is the author of a large medley of essays(650pages), Chronicling the Golden Age of Astronomy, which showcases the extraordinary lives of amateur and professional astronomers over four centuries of time.

Post Scriptum:

1. The Zeiss Terra has a two year warranty, which is enacted once you register the product on the Zeiss website. Cross-checking is thorough, requiring the serial number, and the name & address of the place of purchase. After checking these details, you receive a confirmatory email from the Zeiss Sports Optics team, welcoming you to the world of Zeiss.

2. The little foldable Zeiss Terra is very suitable for those adults with unusually small inter pupillary distances (closely spaced eyes) and children.

3. The overall light transmission of the Zeiss Terra ED is 88 per cent. Source here. This is exactly the same as the Swarovski CL Pocket(non-ED just in case Pepperidge farm forgets, ken ) binocular. Source here. Zeiss Victory Pocket binocular light transmission is 91%. Source here.

4. The family of magpies came back to the Rowan tree in my garden, as they always do, just before sunset. Here is a picture of four ( I think!) individuals settled in the tree branches at 20.09pm local time on the evening of October 6 2019.

Wee magpies hunkering down for the night in my Rowan tree.

5. After a week of abysmal weather, with endless cloud and rain, I finally managed to test the little Zeiss Terra pocket binocular on a very bright gibbous Moon at 10:25 pm local time on the evening of October 10 2019, when it was within an hour of meridian passage. At the centre of the field, it delivered a beautiful, clean and razor sharp image with no false colour. The background sky was good and dark with little in the way of diffused light. Internal reflections were pretty much non-existent with the Moon in the centre of the field. Only when it was placed just outside the field did I detect some minor flaring. Moving the Moon to the edge of the field threw up some slight lateral colour, bluish at its southern edge, and green-yellow at its northern edge. These results were entirely consistent with my flashlight testing. This will be a useful Moon-gazing glass!

6. May 11 2020: This afternoon I received a phone call from the Zeiss team clarifying that the Terra pocket binoculars have indeed moved production to China, but they also reassured me that the quality of the product is identical to the original Japanese-made instrument, as is the packaging, accessories and two-year warranty. Not all employees were aware of this until recently and this was the root source of the recent confusion.

Three Good Binoculars that Won’t Break the Bank.

Three binoculars offering very good performance for a modest price.

April 14 2020

As my regular readers will know, I’ve spent quite a lot of time in recent years seeing what’s what in the binocular market. But just like the telescope market, all is not what it seems. You don’t always get what you pay for and you can find genuine bargains that offer much better bang for buck than those usually presented on internet forums frequented by amateur astronomers, birders and the like. The trouble with these forums is that they usually become hijacked by folk who insist on using and promoting premium products that are usually way beyond the price range of most enthusiasts and many good products simply fall below the radar and so never see the light of day. In this blog, I’ll be presenting three binoculars from the pocket, compact and mid-size aperture range that offer exceptional value for money, having been thoroughly tested(not the usual ‘mickey mouse testing’ seen on the internet) by yours truly in a variety of field conditions.

I’m writing this fully in the knowledge that a lot of folk are hurting financially at the moment, owing to the international crisis precipitated by the corona virus. Millions of people’s mobility has been severely restricted and so there may be quite a few individuals out there who may be looking for cost-effective products that will make life in lock-down that little bit more palatable. What better way than a good binocular to bring the world closer and to examine the beauty of the creation from the vantage of a garden, rooftop or balcony?

All of the binoculars featured in this blog are well made, coupling very good mechanics with excellent optics, all have price tags under £150(UK) and all come with a ten-year guarantee so that if you’re not fully satisfied with the product you can always return it in due course. These instruments include:

The Opticron Aspheric LE 8 x 25 pocket binocular

The Nikon Prostaff 7S 8 x 30

The Barr & Stroud Savannah 8 x 42

 

The Opticron Aspheric LE 8 x 25:

The Opticron Aspheric LE 8 x 25 has an rugged aluminium body with dual hinge design that allows it to be folded up into a very small size so that it fits inside a pocket.

Are you looking for a well-made pocket glass that you can take anywhere to deliver very sharp, high-contrast images of your environment? The Opticron Aspheric LE 8 x 25 may be all the binocular you might need. Opticron is a well established British firm with a long history of delivering high quality optical products to their customers. The unit has fully multi-coated optics, high-reflectivity silver coated, phase corrected BAK-4 prisms to maximise light transmission. My glare tests using a very intense artificial light source shows to show up internal reflections and unwanted glare revealed that not one, but two of these instruments produced very satisfactory suppression of stray light. This is a good indicator of high contrast optics even in difficult lighting situations, such as glassing artificial light sources at night and observing heavily back-lit daylight scenes. The unit shown above was purchased for my wife and was acquired before the newer model was brought to market. The only difference between the newer and older models is that the former are fully water- and fog-proof, purged internally with inert, dry nitrogen gas.

The Opticron Aspheric LE folds out to suit most anyone’s inter-pupillary distance( IPD) and has well made twist up eye cups.

Tipping the scales at about 290g, the little Opticron pocket glass has good quality, twist-up eye cups that hold their position well and possess generous, 16mm eye relief, making them well suited both for eye-glass wearers and non-eye glass users alike. The Opticron also features a built-in lanyard for easy transport in the field so there’s no need to fit a strap. Focusing is smooth and precise, and the newer unit has slightly better rubber armouring for comfortable handling in the field. Close focus is also exceptional on these units. I measured one at 1.4 metres!

The Opticron Aspheric LE  8 x 25 allows you to get to work or play quickly.

Optically, these little Opticrons serve up very sharp, high contrast images and their aspherical ocular lenses ensure that the image does not degrade appreciably even when subject is imaged at the edge of the field. The only slight downside with these units is their relatively small field of view; just 92 metres at 1000m(~5.2 angular degrees),  but the fine optics more than makes up for this small field!

The newer model comes with a beautiful neoprene carry case that perfectly fits the binoculars.

The well-made logoed carry case fits the pocket binocular exceptionally well for easy transport and storage.

Retailing for £129(UK), these pocket glasses will provide years of hassle-free entertainment that is sure to delight anyone who uses them! I’ve often employed them for limited astronomical applications too, where they have proven their worth in delivering razor sharp and glare free images of the Moon, bright planets, and with an almost flat extended field, are well suited for glassing larger star fields and bright deep sky objects.

An elegant, ultra-portable pocket binocular.

 

The Nikon Prostaff 7S 8 x 30:

The Nikon Prostaff 7S 8 x 30 compact binocular.

The next binocular featured in this blog was a very pleasant surprise! I took a punt on the Nikon Prostaff 7s 8 x 30 out of sheer curiosity, since the vast majority of comments made by their owners were very positive indeed. And I can now say they weren’t wrong!

Weighing in at 415g, the Prostaff 7s 8 x 30 is very light weight for a binocular with these specifications. The optics are fully broadband multi-coated and the prisms are phase (and silver) coated for bright and sharp images. Being significantly larger than a pocket glass, they are easier to hold and easier to engage with owing to their larger exit pupil( 3.75mm). I was very surprised to learn that the Prostaff 7s has a higher light transmission than Nikon’s more expensive offering, the Monarch 8 x 30, as revealed in my more in-depth review I conducted on this binocular earlier this year. With a length of only 12cm, it is only one centimetre longer than the Opticron pocket glass keeping it very small and tidy!

The Nikon Prostaff 7s 8 x 30 has good quality twist -up and down eye cups that hold their position very well.

Despite being very light weight, it’s very easy to hold steady in my hands owing to its shorter bridge which exposes a larger area to wrap your hands around the barrels. The big focus wheel is buttery smooth and moves effortlessly with zero backlash or slack from close focus (just over 2 metres) to infinity in less than one revolution. The Prostaff 7S has well-made, twist-up eye cups that offers generous (15.4mm) eye relief to suit both eye glass wearers and those that don’t. The poly-carbonate body is overlaid by a thick rubber-like armour with exceptional grip. In addition, the instrument is fully water proof (1m depth for 10 minutes according to the user manual) and being filled with dry nitrogen gas, is also fog proof.

My tests show that the little 8 x 30 was superior to the Opticron in suppressing glare and internal reflections, which came as yet another pleasant surprise to me. Optically, this compact-sized binocular packs a powerful optical wallop. Having a true field of 114m @ 1000m (6.5 angular degrees), the image is very sharp and contrasty, and retains its sharpness almost to the very edge of the field. In addition, there is very little attenuation of light as one moves from the centre to the field stop, unlike many other models I have tested(sometimes costing many times more). This level of optical excellence is achieved by keeping the field of view on the small side compared with many other 8 x 30/32 units you are likely to encounter. I found this a very acceptable compromise though, as 6.5 degrees is still plenty good enough for most applications.

Although the Prostaff 7S units don’t employ ED glass, the chromatic aberration is, to all intents and purposes, non-existent, and delivers no appreciable reduction in performance over an equivalent unit employing ED glass. Like I said before, don’t fall for marketing hype. Most users won’t be able to tell the difference between a unit with ED glass elements and one without, provided that quality optical components are properly assembled in house.

The Prostaff 7s 8 x 30 compact binocular has an exceptionally smooth focus wheel for precision focusing in the field.

Having both larger objective lenses and exit pupils, the Nikon Prostaff 7s is noticeably superior to any pocket glass in low light conditions, where it serves up brighter images at dawn or dusk or on dull winter days. But its biggest performance difference over pocket glasses comes into play when turned on the night sky, where its greater light grasp pulls in significantly fainter stars, making deep sky observing more rewarding.

A fantastic performer for a great price: the Nikon Prostaff 7S 8 x 30.

Together with a good rain guard and high quality padded neck strap featuring the Nikon logo, this 8 x 30 unit is likely to please the vast majority of users and will deliver flawless performance for many years. All in all, the Nikon Prostaff 7s 8 x 30 offers exceptional value for money in today’s market, combining great ergonomics with remarkable optical performance for its modest price tag (~£140 UK).

The Barr & Stroud Savannah 8 x 42:

The Barr & Stroud Savannah 8 x 42 super-wide angle.

Now for a very special binocular. When I started out looking at the modern binocular market, I took the advice of a number of more experienced glassers who recommended I try a Barr & Stroud roof prism binocular. Now, several years on, I’m very glad I did. Every model I have tried for their range has been impressive. But one model in particular stood out from the crowd; the Barr & Stroud Savannah 8 x 42. Having owned and tested two samples of this product, I can say, hand on heart, that it’s got to be one of the best bargains your money can buy.

Built like a proverbial tank, it sports a whopping 143m@1000m true field; one of the widest on the market for a binocular with these specifications. But unlike a string of other models in this modest price class, you get an extraordinarily well corrected field with an enormous sweet spot that keeps the object well focused even near the edge of the field.  With a larger exit pupil of 5.4mm, the 8 x 42 is supremely comfortable to use, even by complete novices, since it is very easy to get good eye placement. The body is covered with a thick rubberised armouring, which provides excellent grip even in tricky conditions. Unlike most other roof binos in this price class, the Savannah has its dioptre ring located just ahead of the focus wheel, making it very easy to access should you wish to tweak the optics in the right barrel. On the downside, its location makes it that little bit easier to knock out of place while glassing in the field and so a little bit more care should be afforded to it when removing the instrument from its hard, clam shell case.

Everything about the Barr & Stroud exudes quality. The focuser is a joy to use and one of the best I have experienced in an 8 x 42. It is buttery smooth and moves effortlessly with absolutely no backlash or bumpiness in either direction, taking nearly two full revolutions from its closest focus (under two metres) to beyond infinity. The eye cups are of very high quality and twist up to give extremely comfortable eye relief. What’s more, they remain firmly in place even when significant pressure is applied to them. The instrument is fully waterproof(1.5m for three minutes) and is dry nitrogen purged to eliminate internal fogging when used in cold, damp conditions.

My glare and internal reflections testing showed that the Savannah has exceptional control of stray light and the result is that you get very punchy, high-contrast images. Indeed, the only binocular that has produced better results than the Barr & Stroud Savannah is my little Leica Trinovid BCA 8 x 20, but at a price fully three times the asking price of the former! It has noticeably superior control of diffraction spiking (tested on night light sources) compared with a Zeiss Terra ED 8 x 25 and the aforementioned Nikon Prostaff 8 x 30 and Opticron Aspheric LE.

The Barr & Stroud Savannah 8 x 42(right) has exceptional glare and internal reflection suppression that is only just bettered by the premium Leica Trinovid 8 x 20 costing three times more.

The first model I acquired was second-hand but developed a dioptre fault. But I received a brand new instrument from the parent company who own Barr & Stroud,Optical Vision Limited(OVL) and the rest, as they say, is history. The model features fully broadband multi-coatings on all optical surfaces and phase coated Schmidt-Pechan prisms to boost light transmission and image contrast. It ‘s extremely sharp, even when compared with premium models. In one series of tests I conducted in the summer of 2019, the Barr & Stroud Savannah 8 x 42 yielded images that were only very slightly less sharp compared with an optically perfect Swarovski EL Range 10 x 42. I believe the vast majority of users will be delighted when they look through this instrument. Don’t let zealous binocular gayponauts coerce you into buying a model costing many times more before checking this unit out first!

It might be all the 8 x 42 you need!

The large well-made eyecups and buttery smooth focuser on the Barr & Stroud Savannah make for supremely comfortable viewing.

The 8 x 42 serves as one of the best all-round binoculars for a wide variety of glassing applications, whether it be bird-watching, hunting in low light and for casual stargazing. Its nearly flat, super-wide field will delight those who wish the cruise the Milky Way or  ogle large deep sky objects. The only downsides are its weight and slightly lower overall light transmission compared with premium models; at 820g the Savannah is not light by any means but I suppose that, in creating the highly impressive near-flat and super-wide field of view, it needs more optical components to execute this correctly and thus the trade-off is reduced portability and reduced overall light transmission. That said, unlike the two other binoculars discussed in this blog, the Barr & Stroud Savannah 8 x 42 can easily be affixed to a tripod or monopod for ultra-stable viewing, should you require it.

The Barr & Stroud Savannah 8 x 42; a truly remarkable value in today’s market.

This impressive binocular is always a joy to hold in one’s hand and the images it serves up keeps you coming back to it again and again and again.  And while you can pick this model up for about £120, I would rank it as my personal favourite binocular. It’s just a supremely sweet instrument made by a company that once supplied optics to the British Navy during two world wars. And that counts for something!

Storing and Transporting the Binoculars

There is further good news when you purchase any of these binoculars. They all come with good quality carry cases. I have already highlighted the nicely designed yellow and black neoprene case fitting the newer Opticron Aspheric LE(illustrated earlier in this blog). The Nikon Prostaff 7s comes with a black padded case with the Nikon logo on the front and fits the binocular very well together with its strap wound tightly around the body. The Barr & Stroud Savannah has arguably the best quality case of the lot though. As you can see form the image below, the 8 x 42 comes with a hard clam shell case that can be zipped up to seal in the binocular and keep out dust and moisture – the destructive enemies of all optical instruments. As with all of my binoculars, I highly recommend placing a sachet of silica gel desiccant inside their cases, as well as  leaving the caps for both the objective and eyepiece lenses on for added protection.

All three binoculars featured in this blog come with good quality carry and storage cases. On the left, the original Opticron Aspheric LE had a simpler padded case to the one now being offered. the Nikon Prostaff 7S case is featured in the middle, followed by the hard clam shell case of the Barr & Stroud 8 x 42 Savannah(right).

Well, I hope that you found this short blog useful. Above all, I hope you’ll agree that you don’t have to spend a small fortune to get good optical and mechanical quality. Indeed, those days are well and truly behind us!  And if you take reasonable care of your binocular it will provide flawless performance for many years to come.

Thanks for reading!

Neil English is the author of seven books and several hundred magazine articles in amateur and professional astronomy. He has many decades of experience testing and evaluating all manner of astronomical equipment. You can help him continue this work by purchasing one of his books. 

 

De Fideli.

Product Review: Nikon Prostaff 7S 8 x 30.

The Nikon Prostaff 7S 8 x 30.

In recent years, a flood of high-performance 8 x 30 roof prism binoculars have hit the market to cater for the demands of birders, hunters and nature enthusiasts looking to blend the comfortable and immersive performance of larger 42 and 50mm models with the smaller and lighter frames usually only found in compact or pocket binoculars. For example, Swarovski have successfully launched their CL Companion in 8x and 10x 30mm formats and Nikon have introduced a range of 8 x 30 models varying both in price and quality. While their flagship model – the HG 8 x 30 – retails for about the same price as the CL companion(£800 to £900 UK), Nikon also offer a number of more economically priced units in their Monarch 7 and Prostaff 3S, 5S and 7S models.  Curious to test out one of these models, I took a punt on the Prostaff 7S 8 x 30 model, which I was able to buy at a cost of £139 including delivery. Was it worth the cost? Absolutely yes! To see why, read on.

The package was boxed away nicely and included the 8 x 30 binocular, a quality padded neck strap, an instruction manual in a number of different langauges, and plastic rainguard and objective dust caps. The Prostaff 7S also comes wth a 10 year (non-transferable) warranty.

The Nikon Prostaff 7S 8x 30 package.

My decision to purchase this unit was not entirely blind however. I became most intrigued by a very favourable review of this binocular from Allbinos.com as well as a string of positive reviews posted on amazon.co.uk.  Allbinos have cultivated a good reputation with die hard binocular enthusiasts owing to their impartiality and stringent testing regimes. That this binocular did so well in their tests is not surprising(in retrospect), as you’ll soon discover!

First Impressions: The binocular arrived in perfect condition. From the moment I first prized the instrument from its soft, black carry case, I was very impressed with the fit and feel of the instrument. The Prostaff 8 x 30 is exceptionally light weight; just 415g in fact, thanks to a tough, polycarbonate body overlaid by a thick, textured rubber overcoat with excellent grip. That makes it even lighter than the 8 x 32 Celestron Trailseeker(453g) I have been using in recent times. The focus wheel is exceptionally smooth with absolutely no backlash when racked clockwise or anti-clockwise from one extreme of focus travel to the other, and is also overlaid by the same thick rubber that attends the body armouring, making it wonderfully easy to manouevre either with or without gloves. From end to end, the focus wheel rotates through about 340 degrees (so less than one revolution), which translates into a very quick and responsive way to get from close up to far away with very little effort.

The Prostaff 7S 8x 30 has high quality twist-up eyecups for comfortable use with or without eye glasses.

The dioptre adjustment is located in the standard position for most binoculars offered at this price point; that is, under the right ocular lens. It is rigidly held and has a mark on it which enables the user to precisely record the optimum position for one’s eye. The unit is water proof(10 minutes at 1m depth), O-ring sealed and nitrogen purged to prevent internal fogging and corrsion of any metal parts housed inside the barrels. The eyecups are of high quality, rubber-over-metal and have four positions from fully down to fully up. They hold their positions very well, even when considerable pressure is applied to them, and stay rigidly in place in routine use. I found that the most comfortable position for my eyes was to extend them fully upwards, where they provide a comfortable 15.4mm of eye relief. That’s good enough for both eyeglass wearers and those(like yours truly) who prefer to view without glasses. The instrument is 11.9 cm long(with the eycups fully down) and 12.3 cm width(fully extended)

The black and gold livery of the Prosfaff 7S 8x 30 is very eye-catching.

The bridge has a single central hinge that enables one to adjust the IPD with just the right amount of tension so that once adjusted, they maintain that position very well.

The Nikon Prostaff 7S 8 x 30 comes with a plastic rain guard to cover the eyepiece lenses and plastic objective caps that clip tightly into the recessed part of the objectives. Some folk have cried foul of these because they are plastic but I’ve not had that experience. I actually prefer them to the regular synthetic rubber caps since they remain tightly in place and so do their intended job  perfectly well.

Ergonomically, this little bino was a very pleasant surprise! I have always found the Celestron Trailseeker 8 x 32 quite tricky to hold in my rather small hands(for a bloke) well owing, to its very large central bridge. As you can see from the photo below, compared with the Celestron, the Nikon Prostaff 7S has a shorter bridge which enables me to wrap my hands firmly ’round the top end of the barrels much more effectively, whilst enabling me to focus using my left index finger.

The Nikon Prostaff 7S 8 x 30(right) has a significantly shorter central bridge than the Celestron Trailseeker(left), making it much easier to grip with both hands. Note the absence of a tripod stalk on the Nikon, which also frees up some space.

Another good design feature of these Prostaff 7S binoculars is their deeply recessed objective lenses, which affords protection from dust and rain, as well as serving as a barrier against the contrast-robbing peripheral glare.

The objective lenses on the Prostaff 7S are deeply recessed.

Optical Testing

The specifications supplied by Nikon state that the Prostaff 7S is fully multi-coated with a phase coating applied to the roof prisms. Light throughput is boosted by a mirror coating(possibly aluminium but more likely silver). By itself, these statements are meaningless unless one assesses the optical performance of the binocular in person. Indeed, I had learned from previous acquisitions that you don’t always get what you pay for.

But right from the get go, this little Prostaff impressed. As is my usual custom, I started by testing how good the binocular handled stray light and glare but performing my iphone torch test. This involves turning my torch up to its brightest setting and aiming the binocular directly into the light from just a few metres away. The result was excellent! Compared with my control binocular; the 8 x 42 Barr & Stroud, it showed an equally clean image, with no diffused light and only the merest amount of internal reflections. The Prostaff 7S did exhibit a fairly prominent diffraction spike though – which is common in roof prism binoculars –  much more than in my 8 x 42 control, which shows only the merest trace of a spike in comparison, but less intense than in my Zeiss Terra pocket glass. Testing the binocular on a bright sodium street lamp at night also showed excellent results, with no annoying internal reflections, excellent control of glare and a very modest diffraction spike. These results convinced me that the binocular ought to produce excellent contrast in daylight images, especially when pointed at strongly backlit subjects.

The Nikon Prostaff 7S 8x 30 passed my iphone torch test with excellent results. The Barr & Stroud 8x 42 control binocular(right) was used as a suitable control owing to its superb suppression of stray light.

Glassing a variety of targets in the open air yielded impressive results too. The image was tack sharp, with great colour rendition and contrast, and it remaiined very sharp from the centre to the very edge of the binocular field. The binocular exhibits very mild pincushion distortion as judged by examining a telephone pole moved from the centre to the edge of the field stop. The brightness of the image was also noteworthy. Despite its lack of the highest reflectivity dielectric coatings, the binocular completely outperformed my 8 x 25 Zeiss Terra(a first-rate pocket glass) in low light conditions at dusk, but was very comparable to the brightness served up by the Celestron 8 x 32, which does have those dielectric prism coatings.

The Allbinos review measured the light transmission of the Prostaff 7S 8 x 30 at about 87 percent; which seems very credible to me. But what’s even more interesting is that it had a higher light transmission than the more costly Monarch 7 – measured at 85 per cent – which has ED glass objective elements.  This provides further evidence against the commonly parroted notion that ED binoculars produce brighter images; they do not! Brightness is much more strongly linked to the quality of the coatings applied to the lenses and prisms in the optical train. The Monarch 7 does have dielectric coatings however, so the Allbinos test result was a little surprising. There is a rational explanation though; having a significantly larger field than the Prostaff 7S, the Nikon Monarch 7 likely has a more complex optical design. And that usually means one or more extra optical components are needed to produce its very large (8.2 degree) field of view.  Indeed, if you look at the transmission data for a variety of ED and non-ED binos made by different manufacturers tested and published by Allbinos, you’ll soon see that ED glass does not, in itself, equate to brighter images.

As the reviewers on the Allbinos website remarked about the Prostaff 7S’  light tramsmission;

They didn’t stint on coatings, though. A transmission level in a wide range of the spectrum not much worse than 90% is something you don’t see often when it comes to roof prism binoculars sold at this price point.

The reader will also note that the state-of-the-art Swarovski CL Companion 8 x 30 has a transmittivity of 90 per cent(as published on  the Swarovski website), so the Prostaff 7S 8 x 30 will more than hold its own against it in low light conditions.

The larger exit pupil (3.75mm) on the Nikon Prostaff 7S makes for much easier positioning of one’s eye sockets than in smaller pocket glasses, which results in very comfortable, immersive glassing, even during prolonged field use. The silky smooth focuser makes this instrument particularly nice to use. Indeed, this little Prostaff has re-kindled my interest in both 30 and 32mm formats because of their sheer versatility. All of these findings raise an interesting and legitimate question: how can Nikon produce such a great performing binocular and market it at a relatively low price point? The answer, to some degree, pertains to its smaller field of view –  just 6.5 degrees. Most binoculars with these specifications have significantly larger fields – usually from about 7.5 to 8.3 degrees. Nikon obviously decided to restrict the field of view so as to maintain excellent image sharpness from the centre to very near the field stop. And that’s entirely understandable. I would personally prefer a smaller, sharper field than a larger one which blurs significantly as one moves out of the central sweet spot. And 6.5 degrees is plenty wide enough. I certainly don’t subscribe to the philosophy that once you regularly experience a 8+ field, there’s no going back. Besides, I already have a most excellent wide angle 8 x 42 binocular which delivers a very expansive 8.2 degree(143m@ 1000m) true field.

Another cost-cutting measure is to use a synthetic polymer to house the optics. This is quite acceptable too, as polycarbonate frames have been tried and tested with many other binocular makers over the years. It also shaves off additional weight to render the instrument lighter and more portable.

Many binoculars display a marked drop off in brightness towards the edges of the field. Not so with the little Nikon Prostaff 7S 8x 30! Indeed, I could detect little or no attenuation in brightness around the periphery of the field during daylight hours, which does add more aesthetic punch to the image garnered by this lightweight roof prism binocular that will certainly appeal to almost anyone who uses it. Chromatic aberration is very well controlled, but like most any quality instrument of this nature, it does show a trace when examining a high contrast object like a telephone pole against a bright background sky and only if you go searching for it. Like I said before in other binocular reviews, any discussion on chromatic aberration in well-made modern glasses like these amounts to little more than drivel.

The underside of the Nikon Prostaff 7S 8 x 30 binocular.

So, to sum up the daylight performance of these 8 x 30 binoculars, I would agree wholeheartedly with the concluding comments proferred by the reviewers at Allbinos:

For a quite moderate amount of money you get an optical instrument without any serious flaw. Due to its physical dimensions it might become your loyal and efficient companion on different trips……………….. we are very pleasantly surprised by the performance of the small Nikon – let’s hope there are more and more such good instruments available on the market. 

Note added in proof: My hunches regarding the lower light transmission of bigger, more complex binoculars appears to be corroborated in this Allbinos review of the Vortex Viper HD 10 x 42. But there are many other examples one can point to by means of illustration.

Ad Astra

Having in my possession a modest collection of binoculars from 20mm up to 60mm aperture, I can say, hand on heart, that 30mm is about the minimum that I would be happy with for regular stargazing. This, of course, does not at all detract from my ongoing blog using smaller pocket glasses, where I wrote (and continue to write) about using these small instruments on the basis of, ” what if these were your only binocular?”

Yes, a 30mm aperture binocular will be vastly superior to a 20mm or 25mm glass when it comes to viewing the heavens. The larger aperture of the objectives and the larger exit pupil render this possible. The Prostaff 7S 8 x 30 pulled in significantly more starlight on virtually all objects I tested the glass on. Views of the showpiece objects, such as the M35, M36 to M38, the Pleiades and Hydaes, the Double Cluster, the Beehive Cluster(M44) and the Coma Berenices Cluster were very nicely rendered in this binocular with excellent contrast, while scanning the late winter Milky Way was a very pleasant experience indeed. Because of its nearly flat field, stars remain sharply focused nearly all the way to the field stop, and I was able to verify the true field of this binocular as being very close to the manufacturer’s published figure of 6.5 angular degrees. I was only just unable to image the two stars at the end of the handle of the Ploughshare(Big Dipper) – Alkaid and Mizar – within the same field. These stars are separated by 6.67 angular degrees.

Overall Conclusions

Worth the price: the Nikon Prostaff 7S 8 x 30 does what it says on the tin.

By most anyone’s standards, the Nikon Prostaff 7S 8 x 30 provides excellent ergonomics and optics given its very modest retail price. And now that the media has decimated the world economy through shameless scaremongering over the coronavirus, this would be a good binocular to acquire if you’re on a tight budget. Personally, I prefer it to the 8 x 32 Celestron Trailseeker(now bequeathed to my my eldest son) because of its superior handling, lower weight, better corrected field and similar light transmission. It’s a joy to use and should give its owners plenty to crow about for many years. In an age of deceptive advertising and influential binocular shills, the Nikon Prostaff 7S 8 x 30 could be all the binocular you might ever need.

 

Highly recommended!

 

Dr. Neil English is the author of seven books on amateur and professional astronomy. Taking no prisoners, he has dedicated much of his writings to de-bunking scientific and obsevational myths promulgated by fake gurus and armchair amateurs who wouldn’t know the North Star from Uranus.

 

De Fideli.

8 x 42 vs 8 x 32; Which is More Versatile?

Two good binoculars: The Barr & Stroud Savannah 8 x 42(left) and the Celestron Trailseeker 8 x 32(right).

Many binocular enthusiasts will often recommend a good 8 x 42 as the near perfect all-round instrument for birding, hunting and astronomy. This recommendation seems sensible enough given their medium size, weight and decent light gathering power for use in bright daylight, low light conditions and stargazing. But the increasingly popular compact 8 x 32 has also earned a respectable place in the hearts of many birders and sightseers owing to its lighter weight but greater light gathering power over a pocket binocular. But that raises an interesting question; which model is more versatile in the long run?

To begin to answer that question, I’ve spent some time comparing and contrasting the efficacy of two binoculars in these size classes; a Barr & Stroud Savannah 8 x 42, which I have written enthusiastically about in a past blog, and more recently, a Celestron Trailseeker 8 x 32, described in more detail here.

Let’s first look at the specifications of both models at a glance:

The Barr & Stroud 8 x 42

Fully multi-coated

Phase coated(probably silver or enhanced aluminium)

8.2 degree FOV(143m@1000m)

5.25mm exit pupil

18mm eye relief

Dry nitrogen purged

Waterproof

810g

Retail Price: £120 UK

The Celestron Trailseeker 8 x 32

Fully broadband multi-coated

Phase coated(high reflectivity dielectric coatings)

7.8 degree FOV(137m @1000m)

4mm exit pupil

15.6mm eye relief

Dry nitrogen purged

Waterproof

453g

Retail Price: £125(recently reduced for clearance owing to the discontinuation of the model)

Performance in Bright Daylight Conditions

Both instruments serve up  very sharp, high contrast images of well-illuminated targets with virtually no chromatic aberration(this is widely exagerrated by many reviewers but is actually not really an issue in any realistic situation. Indeed, in my comparison of smaller high-quality ED and non-ED instruments there has never been a target that I have imaged where ED glass made any meaningful difference to the viewing experience). The Celestron has a narrower field of view and a smaller ultra-sharp sweetspot. The Barr & Stroud displays a wider, flatter field with a noticeably larger sweetspot. The larger exit pupil on the latter makes viewing that little bit more comfortable, since positioning the eye over a larger shaft of light is easier to achieve. Both instruments generate images that are about equally bright under these conditions though. Near equal too is their ability to suppress glare and internal reflections owing to good baffling and high-quality coatings applied to all optical surfaces. The objective lenses are also deeply recessed in both binoculars, offering protection against rain, wind-blown dust, as well as serving as an effective barrier against peripheral glare.

I also noted slight differences between these instruments in colour tone when observing brightly illuminated daylight targets. The Celestron had a more neutral colour tone, whereas those of the Barr & Stroud were ever so slightly yellower and darker in comparison.

The focusing wheels on both instruments are notably different in field use however. The Barr & Stroud possess one of the best focusers I have personally experienced(indeed they have been very good in a number of other instruments marketed by the same company). It is buttery smooth and very easy to adjust in situations where rapid changes of focus are necessary. The Celestron focuser has much more tension in comparison, even after using it for a considerable number of hours in the field. When rapid focusing is required, the Barr & Stroud Savannah is clearly superior, which makes a significant difference when scanning fast-moving targets like birds flying across the field of view.

There is also a significant difference in eye relief between the two instruments. The Barr & Stroud has a whopping 18mm eye relief whereas the Celestron Trailseeker only exhibits 15.6mm in comparison. What this means in practice is that the latter is far more comfortable to use while using eyeglasses. I can see the entire field of the Savannah if I use my eyeglasses but it’s a lot more challenging with the Trailseeker.

The weight difference between the models is considerable however; with the Celestron tipping the scales at just over half the weight of the Barr & Stroud. Indeed the latter is one of the heaviest  8 x 42s currently available, while the Celestron Trailseeker is one of the lightest models in its aperture class. This has a significant  bearing on  prolonged use and transport in the field, where neck strain is effectively eliminated in the light-weight Celestron.

Low Light Performance

On paper, one would reasonably expect that the significantly larger 8 x 42 would prove better in low light conditions, such as those experienced at dawn and dusk, but my testing revealed some surprising results! In a nutshell, the Celestron Trailseeker proved to be much closer to the Barr & Stroud under such conditions! Immediately after sunset on several late January evenings, I found that both instruments produced very similar performance in terms of the brightness of the images garnered of a heavily lichen-adorned tree branch located some 50 metres off in the distance. Indeed, the 8 x 42 only pulled noticeaby ahead well into twilight when the last light of day was ebbing from the landscape. This seemed genuinely puzzling to me, as I fully expected the results to be well, like night and day.  But why though?

The first significant difference between the models relates to the coatings used on the roof prisms in both instruments. The Celestron Trailseeker has state-of-the-art dielectric coatings that significantly improve its light transmission over a similar sized model with lower reflectivity aluminium or silver coatings. Maybe the Trailseeker has better anti-reflection coatings applied to the lenses making up the objectives and the eyepieces? The second thing that I noted is the significantly larger frame of the Barr & Stroud Savannah, which will have commensurately larger prisms than the smaller Celestron, with the implication that more light will be absorbed while traversing the former. That said, I still couldn’t understand why an instrument with 42mm objectives was not pulling very far ahead under such low light conditions than an instrument with only 32mm aperture objectives. Quite frankly, it still didn’t add up!

It was then that I realised that the best explanation possibly pertained to the size of the exit pupil under the same conditions. As any amateur astronomer worth his/her salt will tell you, the pupil of the eye is designed such that it dilates in low light conditions to allow more light to reach the retina. Indeed, this is one of the ABCs in telescopic deep sky observing, where a fully dilated eye pupil shows you much fainter objects than eyes that are newly accustomed to the dark. But while some dilation certainly occurs under low light, I wondered whether there was a limit to how much dilation actually occurs during early twilight, when the differences were observed to be most similar in both instruments. If my eyes only extended from say 2.5mm during bright daylight to a liitle over 4mm in early twilight, the extra millimetre or so offered by the 8 x 42 would be of no significant benefit. Maybe my eyes were just not capable of using the 5.25mm offered up by the larger 8 x 42 under such conditions?

I also noted that the tests on both binoculars were carried out more or less simultaneously for the duration of about 15 minutes, so not long enough to induce big changes in the ratio of rhodopsin(which reaches higher concentrations in darker conditions) to retinal(which exhibits higher concentrations in bright light conditions) In addition, the eye takes quite a long time to effect these biochemical changes, and most certainly longer than the 15 minute duration over which these tests were conducted. Moreover, rhodopsin is still rather labile even in low light conditions such as those encountered during the twilight sessions. However, these findings were quite in keeping with the subsequent experiences I had with both binoculars under well-adapted dark conditions; specfically under a clear night sky with no Moon.

Dark Sky Performace Compared

Donning some dark sunglasses I sat out in a deck chair for about 25 minutes after leaving a bright indoor environment to accelerate dark-eye adaptation. By then I was sure that my eye pupils had dilated to their maximum extent and the process of rhodopsin biosynthesis was well under way. Examining the region centred on Orion’s belt stars, I immediately noted a very significant difference between the glasses; this time the clear winner was the 8x 42 Barr & Stroud binocular. It was easy to see that it was pulling in more numerous and fainter stars in Collinder 70 than the smaller 8 x 32. The same was true when I critically examined the Sword Handle of Orion, and in particular, the marvellous gaseous nebula of M42. The 8 x 42 was very much superior, indicating that my eyes were indeed gathering in more light( as they should do) owing to its larger exit pupil of the 8 x 42 binocular.

That said, the 8 x 32 was more comfortable to hold over prolonged periods(several minutes), owing to its much lower weight and transmitted a surprising amount of light; far more than any pocket glass (25mm aperture or less) I had recalled from memory, yielding quite impressive views of star fields and open clusters like the Auriga Messier trio, then very high overhead in the winter sky. The slower focus wheel on the Celestron was far less of a problem under these viewing conditions owing to the relatively tiny focus adjustments required when viewing astronomical targets, and especially when moving from the zenith to objects imaged nearer the horizon.

Overall Implications

The Barr & Sroud Savannah 8x 42(left) gets my winning vote over the Celestron Trailseeker 8 x 32(right).

So which instrument is more versatile? Unsurprisingly, this is a deeply personal choice and, as such, there are no absolute answers. If you don’t mind carrying around the extra weight, then the 8 x 42 would get my vote. I just love the way the instrument feels in my hands, its solid, Spartan construction, wonderfully sharp, super-wide field of view and spectacular bang for buck. The 8 x 42 is exceptionally easy on the eyes with its very comfortable 18mm eye relief(compared to the considerably tighter 15.6mm on the Celestron) and larger exit pupil, so pulling well ahead as an astronomical instrument, or when glassing under deep twilight conditions. It’s only significant downside over the 8 x 32 is its lack of dielectric coatings on the Schmidt-Pechan roof prisms, but it more than makes up for this with its fine optical quality and sturdy mechanical design. Indeed, the 8 x 42 Savannah remains this author’s personal favourite binocular!

But if weight is a big issue and you like to do all or nearly all of your glassing during daylight hours, then a high-quality 8 x 32 will certainly deliver the readies and thus deserve serious consideration.There are some other models in this binocular size class that are as good, if not better than the Celestron, and at prices that won’t leave you out in the cold; the Vortex Diamondback HD 8 x 32(with its famous ‘no questions asked’ VIP warranty), the Nikon Monarch 7( 8 x 30) and the Hawke Frontier X HD, immediately come to mind, all of which retail in the UK for between £200 and £300 and well worth checking out. If possible, you should try before you buy to avoid disappointment.

 

Thanks for reading!

 

Neil English is the author of several books on telescopes and astronomical observing, but does not endorse bling. He is seriously considering writing a similar text dedicated to binoculars in the future.

PostScriptum: I intend to have my fully dilated eye pupil size measured on my next visit to my optician.

De Fideli.