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 optical perfection: 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!

To be Continued………………………….

 

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.

Product Review: Leica Trinovid BCA 8 x 20.

To establish ‘Limes.’

Back in the summer of 2019, I got the opportunity to test out a very high quality Swarovski EL Range 10 x 42 owned by a fellow villager named Ian. A keen hunter, he uses this binocular to seek out red deer and estimate their distance using the built-in laser telemetry in the instrument. A few weeks ago, I bumped into Ian in the swing park near my home, where he was looking after his young grandaughter, and we struck up another conversation about binoculars. I was returning from one of my walks,  carrying along my little Zeiss Terra 8 x 25 pocket. He was fascinated with this new instrument, being duly impressed with its razor sharp optics, generous wide field, light-weight ergonomics and decent market value. It was then that I discovered that Ian was also the proud owner of a little Leica Trinovid BCA 8 x 20, which he purchased about two years back for casual sightseeing during his summer vacations in the Scottish northwest. Keen to expand my portfoIio of tested instruments, I asked him if he would be kind enough to let me borrow it  for a wee while to evaluate its optical and mechanical performance. He agreed, but did say that he found the Terra to be very comfortable to use and was even considering acquiring one in the future! Fast forward a couple of weeks and Ian dropped by the Leica binocular at my home so that I could begin some tests, the results of which, I will divulge in this blog.

Leica is a German optical firm that has established itself as a world-leading manufacturer of high-end cameras, microscopes, camera lenses, binoculars and spotting ‘scopes for the burgeoning sports optics market. Founded in 1869 by Ernst Leitz, at Wetzlar, Germany, where the original factory remained until 1986, after which time production was moved to the town of Solms to the west of Wetzlar.  In 1973, Leitz set up another large factory in  Portugal, where it has remained to this day. With 1800 employees, Leica has an annual turnover of the order of 400 million Euro, and continues to produce state-of-the art optical equipment for private and public institutions(mostly universities and hospitals) the world over.

The Leica Trinovid line of binoculars has a long history. Leica first began to manufacture high-quality binoculars back in 1907, but the Trinovid line first appeared in 1953. Over the years, Leica has continued to develop their Trinovids, adding new optical technologies to their products where, today, they utilize some of the best glass and optical coatings available.

First Impressions

The quality of the device was immediately apparent to me as I prized the 8 x 20 from its somehwat oversized, soft carry case. Weighing in at just 235g, the Leica Trinovid BCA 8 x 20 measures just 9cm long, 6cm wide and 3.5cm deep when folded up. This makes it one of the smallest and most portable binoculars in continuous production today.

The Leica Trinovid BCA 8 x 20(made in Portugal) folds up into a tiny storage unit just 9cm long and 6cm wide. Note the unusual location of the right eye dioptre setting, which is accessed by turning the objective lens housing.

The binocular has a very traditional dual-hinge system but maintains a very classic look and feel, with an aluminium frame. Unlike their larger binoculars, the BCAs are described as ‘splashproof’, meaning that they will work fine in rainy conditions but are not hermetically sealed or dry nitrogen purged like the majority of roof prism binoculars today. The all-metal chassis is overlaid by a tough rubber armouring, which greatly improves its grip during field use and affords greater protection against accidental bumping or knocking about.

The strong and durable rubber armouring overlaying the aluminium chassis of the Leica Trinovid BCA 8 x 20.

The eyepieces are of exceptionally high quality, being made of metal overlaid by soft rubber cushions for comfortable viewing. They offer just two positions; fuly extended upwards for non-eyeglass wearers(including yours truly) or fully retracted when used with glasses. Eye relief is pretty tight though, at just 14mm, so some eyeglass wearers may struggle seeing the full field. The eyecups hold their position very well and can only be retracted by using considerable downward force. I must say that these are the finest eyepieces I have thus far experienced in my survey of the binocular market. Simply put, they are beautifully designed.

The beautifully designed eyepieces click rigidly into place.

Intriguingly, the dioptre setting(+/-3.5) is located on the right objective lens, which turns either clockwise or anti-clockwise. The focus wheel, which appears to be constructed of a hard plastic, is quite small but moves very smoothly with zero backlash. At first, it’s a bit fiddly to use but with a little practice becomes easier to negotiate, though it may present problems to those who wear gloves.  All in all, the binocular is a study in elegant design. Clearly it was created not only to look good but to feel good in active service.

The Trinovid BCA has a high-quality, somewhat elastic, neckstrap, which is affixed via clips, so can be disengaged from the binocular if so desired. It is comfortable to use. Yet again, an unusual but very nice touch.

The objective lenses are not very deeply recessed in this model, perhaps because its designers aimed to minimise the length of the instrument. Having more deeply recessed objectives serves a number of useful purposes though, including protection against rain and dust, and serving well as an effective barrier against peripheral glare.

The objective lenses on the Trinovid are not very deeply recessed.

Optical Testing

As is customary for me with the arrival of any new binocular for testing, I began by assessing its performance in suppressing stray artificial light, internal reflections and glare. This is easily done by sharply focusing on a bright internal light source – I use my iphone torch at its brightest setting – in a darkened room and sharply focus on the light. Such tests quickly revealed highly satisfactory results. Stray light was very well controlled and very clean, with only very minor internal reflections and no sign of diffused glare often encountered in lesser models. The main artefact was a reasonably pronounced diffraction spike. Indeed, using two small ‘control’ binoculars; my Zeiss Terra 8 x 25 pocket and my recently acquired Celestron Trailseeker 8 x 32 (both of which exhibit excellent performance in this regard), I judged the Leica 8 x 20 to be as good, if not a little better, than my controls. All of these binoculars employ full, broadband multi-coated optics on all glass surfaces, with prisms that are dielectrically coated for highly efficient light transmission. The results predict that the Leica will perform excellently when pointed at strongly backlit daylight scenes, bright street lights and bright terrestrial targets like the Moon. There is no such thing as absolute perfection though. Such a complex optical device will always betray some degree of imperfection under these very stringent tests. I guess, it just comes with the territory!

The high quality HDC coating makes for exceptional light transmission.

In good accord with my flashlight tests, pointing the little Trinovid at a bright sodium street light at night showed no internal reflections, glare and only a very faint diffraction spike that I didn’t find intrusive. These tests were followed up by daylight optical assessments. Looking at tree trunks and branches during bright afternoon conditions showed that this 8 x 20  has excellent optics with a good, wide field of view. The image is tack sharp with a very large sweet spot. There is only slight softening of the images in the outer 10 per cent of the field. Colours are true to form and I detected only the merest trace of chromatic aberration and then only by looking very hard for it(I honestly find this activity rather pointless) on difficult targets. Contrast is exceptional with excellent control of stray light, as judged by imaging targets nearby a setting Sun under hazy sky conditions. There is a normal level of veiling glare which can be removed by blocking the Sun with an outstretched hand. There is also some minor pincushion distortion at the edge of the field but I still judged this to be well above average.

Excellent coatings make the objectives almost disappear.

Some readers will be surprised to learn that Leica did not employ any ED elements in the objective lenses of their BCA binoculars, proving once again that such an addition is not at all necessary to create an excellent optic(the Swarovski CL pocket and larger sibling, the CL 8 x 30 Companion are yet other examples). What really matters are well figured glass elements with high-quality anti-reflection coatings. Looking up its specifications online showed that Leica has spared no expense applying their famous(patented) High Durable Coating (HDC). It purports to be abrasion-resistant with enhanced light transmission, and then there’s the solid P40 dielectric phase coating applied to the Schmidt-Pechan roof prisms. What results is a highly efficient light gathering optic; an especially important commodity for tiny binoculars like these.

The Trinovid certainly delivers optically when the light is good and strong. But it does have some issues which are important to address. Because of its very small size, it’s actually quite challenging to hold steady during field use. It’s small exit pupil (2.5mm) also makes it considerably more difficult to position one’s eyes correctly compared with slightly larger binoculars, such as a good 8 x 25( with a 3.125mm exit pupil). Comparing its ergonomics with my Zeiss Terra 8 x 25 pocket glass showed that the Terra was simply much easier to engage with even though it’s only about 30 per cent heavier(310g). It’s larger frame also gives it the edge in terms of acheiving a good, stable image. This could prove important if the owner intends to use the 8 x 20 BCA for prolonged glassing periods, as the extra effort incurred in accurately positioning one’s eyes over the small exit pupils may induce eye strain with some users, so I think it’s important that people seriously considering this tiny glass try the more popular 8 x 25 units out before making that all-important purchase. Indeed, I believe this point was not lost on Ian when he tried the Terra out in the swing park that afternoon.

In an ongoing blog on using my 8 x 25 binos, I gave mention to why I think good pocket binoculars are quite expensive in the scheme of things. I attributed this to the extra difficulty in accurately positioning the many optical components stably within a scaled-down structure. The Leica Trinovid BCA 8 x 20 seems to follow this rule of thumb. It is smaller than any 8 x 25 model but is also more expensive(about £350 to £400 UK as opposed to £270 for the Zeiss Terra 8 x 25, for example). But there is surely folly in pursuing this to its logical conclusion. For example, would it be sensible to create an even smaller, state-of-the-art 15mm model say, that can fit on two fingers and cost £500?

Of course not! That would be daft. It would be too small and fiddly to use and the amount of light it would bring to one’s eyes- even if it were 100 per cent efficient – would severely limit its use. That’s probably why the other premium binocular manufacturers – particularly Zeiss and Swarovski – have discontinued their 8 x 20 models in favour of 8x and 10 x 25mm units. Indeed, all of this has close parallels to the premium, small refractor market, where folk seem to pay exorbitant prices for tiny, albeit perfect, optics. Is that really sensible? Not in my mind – which is why I turned my back on it- but your mileage may vary!

Assorted notes:

The Leica Trinovid BCA 8 x 20 has ocular lenses just a little smaller than its objective lenses.

The instrument comes with a ten year warranty.

Each Leica binocular comes with a test certificate which claims that it was examined at various times during its manufacture prior to leaving the factory.

The Leica mini-binocular didn’t appear to come with caps, either for the objectives or eyepieces. It does just fit the small Opticron branded rainguard for compact binos however, which I use with my 8 x 25s.

It’s hard to find the ‘made in Portugal’ stamp on the Leica. But it is there, stealthily placed under the left barrel of the optic, and only accessed by fully extending the instrument’s IPD to its maximum where you’ll see: Made by Leica Portugal in good light.

The Opticron-branded rainguard I use for my 8x 25s just fits the smaller leica binocular.

More info on this package here.

Comparison with other Premium Pocket Binoculars

The Leica Trinovid BCA 8 x 20(left)versus with the Zeiss Terra 8 x 25(right). Note the latter’s larger frame and bigger focus wheel.

I spent a few hours comparing and contrasting the Zeiss Terra ED 8 x 25 and the Leica BCA 8 x 20 during bright sunny conditions(for January) and again under dull overcast conditions, as well as looking for performance differences at dusk, when the light rapidly fails afer sunset.

Under bright sunny conditions there was not much difference between both binoculars in terms of optical performance(both are excellent in this regard), except that the Zeiss has a noticeably wider field of view(119m compared with 110m@1000m). Because of its larger frame, larger focus wheel and larger exit pupil, the Zeiss proved easier to handle and  easily rendered the more comfortable, immersive view. The weight difference between these instruments is only 75g, so I don’t think many folk would quibble about the increase in bulk mass.

Under dull overcast conditions, the Zeiss produced a slightly brighter image, which became more and more pronounced as the light began to fade after sunset(around 5pm local time in the last week in January). This ought not surprise anyone, as both binoculars are highly efficient light gatherers and so simple physics dictates that the larger 25mm glass wins.

Close focus on the Leica was estimated to be about 1.8 metres, significantly longer than the Zeiss Terra at 1.4 metres.

Comparison under the Stars

The differences between the 25mm glass and its 20mm counterpart was most pronouced when aimed at the night sky. The larger exit pupil and aperture on the Zeiss Terra pocket allowed me to see significantly fainter stars around Orion’s belt and in the Hyades, compared with the Leica. At first I judged the contrast to be slightly better in the Leica than in the Zeiss but upon reflection, I attribute this to the smaller exit pupil in the former, which naturally generates a darker sky hinterland. The wider field of view in the Zeiss also helps frame objects that little bit better than the Leica. So, for casual stargazing the Zeiss proved noticeably superior to the Leica 8 x 20. I would not really recommend the 8 x 20 for such activities over a larger glass. But neither should anyone expect miracles here. The Leica is designed for daylight use in the main, although one can always enjoy the odd look at the Moon with the 8 x 20 when it is present in the sky.

Comparisons to a Celestron Trailseeker 8 x 32 Compact Binocular

How does the Leica Trinovid BCA 8 x 20 compare with a good 8 x 32 compact binocular?

Comparing a mid-sized, semi-compact binocular like the Celestron Trailseeker 8 x 32 with a diminutive 8 x 20 might seem a little out of place. But I think its inclusion is valid. The Trailseeker is very light; indeed, at just 453g, it ranks as one of the lightest 8 x 32s on the market, but still has many mechanical and optical features that only a few years ago were the preserve of premium binoculars; a magnesium alloy chassis, solid, well-designed metal-under rubberised adjustable eyecups, fully broadband multicoatings, dielectrically coated Bak-4 prisms et cetera.

Comparing the images served up by both the Celestron and the Leica in bright daylight in the open air, my wife and I both concluded that the Leica has slightly better contrast and sharpness across much of the field than the Celestron 8 x 32. With a small exit pupil of 2.5mm, the best part of your eye lens images the field. Edge of field performance is also significantly better in the Leica. But we also agreed that the Celestron was more comfortable to use, owing to its larger exit pupil (4mm). That said, we also reached the conclusion that the Celestron binocular rendered a slightly brighter image even in good light. But while there are perceptible differences between the two instruments, it must be stressed that these differences are small and subtle. Of course, that conclusion will likely upset a few of the more pestiferous premium bino junkies out there, but it is nonetheless true in our experience. The Celestron held its own very well indeed against the sensibly perfect Leica.

But there is considerably more to say about the economical Trailseeker. Move from the open air into a heavily canopied forest or copse and the advantages of the larger aperture binocular become much more apparent. Under these conditions, the Celestron fairs a lot better, delivering brighter images and more information to the eye. And as the light diminishes in the late afternoon, the Celestron clearly pulls ahead, as it ought to do, owing to its much greater light gathering power. At dusk, the differences between the two models are literally like night and day. Under these conditions, the 8 x 32 Trailseeker is vastly superior. It doesn’t matter if the optics in the Leica are sensibly perfect when you can’t see those details.

You see, the little Leica is like an elastic band – stretch it too far and it will break!

The same was true when pointing both binoculars at the night sky. After struggling to peer through the Leica, the Celestron was pure joy!  Its very efficient light transmission(~ 90 percent) and much wider field of view (7.8 degrees) brings so much more of the Universe to your eye!

These results helped us both to appreciate just how good the Chinese-made Celestron Trailseeker 8 x 32 really is. At roughly one third of the UK price(recently reduced to half its originanl market value(~£250) for clearance) of the Leica, we’d both say that it delivers 90 per cent of the bright, daytime performance of the Leica and vastly superior low light and night time performance. In many ways, this small and light-weight 8 x 32 is a more versatile performer than the 8 x 20 Leica Trinovid BCA, and those wishing to use their binoculars in more compromised lighting conditions would probably be better served with a good instrument in this size class.

And I have to ask this question again: is a weight of 453g really anathema to those who want to travel ultra-light?

nota bene: these comments regarding the Celestron Trailseeker 8 x 32 are also applicable to the previous discussion of my Zeiss Terra pocket glasss, in case you’re wondering.

These tests affirmed the excellent bang-for-buck the Celestron Trailseeker really represents. Veteran binocular enthusiast and fellow author, Gary Seronik, is dead right in highlighting these recent trends: mass produced, Chinese-derived optics are now coming so awfully close to premium performance-both optically and mechanically – that I would have reservations shelling out much more of my hard-earned cash just to get slightly better optical performance and the right to brag! For these reasons, I’m very pleased with and have no plans to upgrade the 8 x 32 Celestron; it will remain as part of my binocular stable.

Conclusions

The Leica Trinovid BCA 8 x 20: lean, mean optical machine.

The Leica Trinovid BCA 8 x 20 is a beautifully made pocket binocular that exudes elegance in both its solid mechanics and optics. It produces sensibly perfect images, rich in contrast and colour, whilst maintaining a very high degree of sharpness across the entire field. Perhaps uniquely, its advantages and disadvantages both pertain to its very small size.  Provided one knows its limitations though, it ought to provide its owners with many years of service as a high-quality, ultra-portable optical system that can be used for casual glassing at sports events, mountain climbing, hiking, birding, general sight-seeing and even some limited astronomical viewing.

I found my time with the little Leica binocular to be a particularly enriching experience. While it is expensive, it is certainly money well spent, especially if you plan to use it on a regular basis. Yet again, I know why Ian chose this little optical marvel. During the very long days of a Scottish summer, when the light is good and strong, I can imagine him enjoying this super light binocular for hours on end.

Highly recommended!

 

The author would like to extend his thanks to Ian for lending him the Leica Trinovid BCA 8 x 20 for this review.

Explore More:

Ken Rockwell’s Review of the Leica Trinovid BCA 8 x 20

Best Binocular Review of the Leica Trinovid BCA 10 x 25

Neil English is the author of seven books in amateur and professional astronomy. He has ambitions to write a full-length book on binoculars in the future to help his fellow amateurs find genuine bargains and de-bunk myths promulgated by binocular gayponauts and con artists over the last few decades.

 

De Fideli.

Product Review: The Celestron Trailseeker 8 x 32.

The Celestron Trailseeker 8 x 32 mid-size binocular.

Are you looking for a good quality mid-size binocular but don’t have £1000+ to spend on a Swarovski or a Leica or some such? Perhaps you’re looking for a nice Christmas gift for a loved one or a friend? Well, the Celestron Trailseeker 8 x 32 binocular could well be all the instrument you need!

If you’ve been following my binocular blogs, you’ll know that I have had to follow a very steep learning curve in order to bring my readers genuinely good bargains. And while it is generally true that you get what you pay for, there are always products that surprise in very pleasant ways, and this little binocular is one such instrument!

Celestron is not a name you’d normally associate with a high-quality roof prism binocular, but their optical engineers have successfully designed a great product in their Trailseeker range. The Trailseekers all feature full broadband multicoatings on all optical surfaces. The BAK-4 Schmidt-Pechan prisms are both phase and dielectricly coated to increase light transmission to the order of 90+ per cent, making it as efficient as ultra-premium models costing many times more.

The binocular measures 4.8 inches wide and 4.8 inches deep, standing just 1.9″ high; so very compact and easy to store in a backpack or small carry case. The binocular can be easily mounted to a tripod or monocular for additional stability.

My flashlight tests carried out indoors, as well as those conducted out of doors on bright street lighting and strongly backlit scenes showed that this model has excellent stray light and glare control. Indeed, its baffling of stray light is up there with the very best binoculars I have had the pleasure of testing. I was literally blown away by how resilent this binocular is to the intrusion of stray light! What that means in practice is that you get very high contrast images, rich in detail that would impress most anyone who tries them out!

The Trailseeker has a very robust magnesium alloy chassis; a feature often only found on premium models.

The binocular has a very strong and robust magnesium alloy chassis that is often only offered in the most expensive brands. It is also remarkably lightweight, tipping the scales at just 454g(16 oz). The strong, lightweight alloy frame also means that it will withstand knocks and bumps better than other models having cheaper plastic or ploycarbonate housings. The optics are 0-ringed sealed and purged with dry nitrogen gas to prevent internal fogging during cold-weather applications and corrosion of any metal parts used inside the instrument. The chassis is finished in a thick, rubberised green armouring that has excellent grip and which protects the main body from the elements. The underside of the binocular has neat thumb indents that make gripping the instrument very intuitive.

The underside of the Trailseeker has neat thumb indents that make handling the instrument very easy and intuitive.

The eyecups are of very high quality. They are made from solid metal with a soft, rubberised finish that makes them very comfortable to observe through. The eyecups twist up with two stops and hold their positions very well indeed, with absolutely no play. The eyerelief is 15.6mm which is adequate for most eyeglass wearers. Close focus is about 6 feet and the field of view is a very generous 7.8 angular degrees(136m@1000m).The dioptre setting is located under the right ocular lens and has just the right amount of friction to keep it rigidly in place from day to day, and from week to week.

The focuser and ocular lenses of the 8 x 32 Celestron Trailseeker.

Optically, the 8 x 32 Trailseeker packs a very powerful whallop. The instrument arrived well collimated out of the box, as evidenced by the perfectly correlated left and right eye images of a chimney located about 150 yards in the distance. The images are razor sharp with a large central sweetspot, softening as you move toward the edge, just like any other binocular. Chromatic aberration is a total non issue(I think this issue in many good quality binos available today has more heat than light). I see a lot of amateurs making bold claims about how ED glass elements make the image ‘brighter’ but in reality, the brightness of the image in the best quality binoculars has little to do with ED glass and much more to do with the quality of the coatings(particularly those of the dielectric variety) employed on the roof prism. For example, I was quite taken aback when I tested this unit out in low light conditions during dusk, when they completely outperformed a very high quality 8 x 25 pocket binocular lavished with premium ED Schott glass and dielctric coated roof prisms. There was no magic though; the very efficient light gathering capabilities of the Trailseeker’s larger 32mm objectives stole the show; it was much brighter, no ifs or buts about it!

A Curious Aside: I wanted to get to the bottom of this somewhat ‘fishy’ claim regarding ED glass, you know; that it gives brighter images and all that, so I decided to investigate some products on line. I mean, I can see why a better focused image in an ED instrument would confer a very slight advantage over a standard achromatic unit with the same coatings, but certainly not to the extent some folk have claimed in the past. Well, I didn’t have to search long before I stumbled on a comapny, Hawke, who make a few models of 8 x 32s, and out of sheer dumb luck(not really), I was able to compare the specifications of their Endurance ED 8x 32 and their Fronier HDX 8 x 32. As you can see from the specs, the Endurance ED does indeed have ED glass, while the Fronteir HDX does not. However, it is the latter that sells for a higher retail price(£259 as opposed to £199)! The one significant difference between these models is that the Endurance ED does not have dielectric coatings on the prisms while the HDX model does. And as this chap confirms, the HDX delivers the brighter image!

So there you have it!

I will further investigate these claims in a later blog, God willing.

No’ bad ken?

NB: The author has no affiliation with any of the binoculars discussed in any of his blogs.

A good design feature: the deeply recessed (9mm) objectives are well protected from rain, dust and peripheral glare.

Although not my favourite size of binocular, the 8 x 32 format is great for birding and other nature studies. Its greater light grasp and generous field of view will enable the user to work under fading light more efficiently and for longer than any pocket glass. The central focuser is well made but was a little on the stiff side when I first acquired it. But with regular use, it has loosened up nicely to allow good, fast focusing on mobile targets like birds in flight, or scurrying squirrels racing up and down a tree trunk. Going from one end of the focus travel to the other involves turning the focus wheel through one and a half full revolutions.

The Celestron Trailseeker 8 x 32 has very high quality twist up eyecups which make viewing through them very comfortable and immersive.

The little Celestron Trailseeker 8 x 32 produces very nice images of the heavens. Looking at a rising full Moon in a frosty winter sky showed very sharp, contrasty images rich in detail, with virtually no stray light that was all too easily evident in a few lesser instruments I have tested. Moving to the edge of the field does reveal some lateral chromatic aberration and some image softening but it’s perfectly acceptable to my eye. What is more, some of these off-axis aberrations can be effectively focused out. Star fields are beautiful and sharp with a jet black sky background, and the Trailseeker has served up very impressive views of some showpiece deep sky targets such as the Pleiades, the Hyades, the Sword Handle of Orion, the Alpha Persei Association and the great spiral galaxy in Andromeda. Stars stay sharp and pinpointed across the majority of the field, with only the outer 20 per cent or so beginning to show some enlargement. That said, I found this imperfection to be very acceptable. Indeed, you would have to shell out many times the modest cost of this binocular (£126) to get anything better in this regard methinks!

Unlike many other high quality binoculars, the accesories that come with the Trailseeker are also of exceptional quality. You get a very nicely made carry case that fits the instrument perfectly(shown above). You also receive a very nicely padded neckstrap with a Celestron orange logo.  That said, I discovered a slight hitch when I attached the supplied neck strap; when I tried to fold it around the binocular to insert it inside the carry case, it proved very difficult and caused the case to bulge outward a bit more than my liking. In the end, I elected to attach a lighter but lower quality strap to the binocular as an interim measure. The instrument also comes with a good quality binocular harness, though I’ve not tried it out for size yet. In addition, the binocular comes with fully attachable rubber ocular and objective lens covers, a microfibre lens cleaning cloth, and a neat user manual in five modern languages. The package is protected by Celestron’s limited lifetime warranty.

The Celestron Trailseeker 8 x 32 package.

All in all, the Celestron Trailseeker is a most impressive piece of kit and it’s obvious that the company cut no serious corners in bringing these high quality instruments to market. I think it represents exceptional value for money in a market saturated by a string of  similarly priced, but lower quality offerings. Kudos to Celestron for making these instruments available at such an incredible price(they originally retailed for over £250 when first launched but are now widely discounted)!

Disclaimer: The instrument was purchased from Tring Astronomy Centre, the staff of which proved very professional and who insured a super fast delivery.

Additional Information:

Promotional Video on the Celestron Trailseeker Binocular Range.

BBR overview of the external features of the 10 x 32 Trailseeker Binocular.

Don’t just take my word for it: read what other purchasers have said about the Celestron Trailseekers.

BBR Review of the 10 x 32 Celestron TrailSeeker Binocular.

BBR Review of the Celestron Trailseeker 8 x 42 Binocular.

 

Neil English is the author of seven books in amateur and professional astronomy, including a 665 page history of visual astronomy: Chronicling the Golden Age of Astronomy, favourably reviewed by several amateur and professional astronomers.

 

De Fideli.

Old vs New.

How does a classic Zeiss binocular square up to a modern roof prism binocular?

Unlike telescopes, which are mainly used by dedicated amateur astronomers, binoculars, for obvious reasons, are owned and used by a much broader cross section of the general population. When my students get to know me, they will inevitably have to endure my unbridled enthusiasm for optical devices of all kinds lol, and that includes binoculars. One of my mathematics students, Sandy, expressed an unusual interest in some of my instruments, and he further informed me that his parents, who run a small ferrying business at Balmaha, on the shores of nearby Loch Lomond, used several binoculars in their everyday work. My interest was further piqued when Sandy told me that his grandfather owned a big Zeiss binocular, which was inherited by his father and would eventually be passed on to him in the goodness of time. I asked Sandy whether he would be willing to bring the Zeiss binocular by so that I could have a look at it. After checking with his parents, Sandy agreed and kindly allowed me to use it for a week in order that I could assess it and give it a good clean. Naturally enough, I jumped at the opportunity!

The instrument, a Carl Zeiss Jenoptem 10 x 50W porro prism binocular, came in a lovely leather case; a far cry form anything made in this era.

The Zeiss Jenoptem 10x 50W complete with original leather carry case.

The instrument had no lens caps and so had accumulated quite a bit of grime on both the ocular and objective lenses over the years. The Jenoptem, which was manufactured in East Germany(DDR), featured a Zeiss multi-coating, which helped me to date it to after 1978, when the company apparently began to apply their anti-reflection coatings to all the lenses and prisms in the optical train. So my guess is that it was probably acquired in the early 1980s. I believe Zeiss Jena offered a higher quality porro 10 x 50 in the Decarem line around the same period, but I have not had the pleasure of testing one of these units out.

The Zeiss Jenoptem is multi-coated.

The instrument has a very Spartan look and feel about it. Weighing in at about 1 kilogram, the Jenoptem is built like a proverbial tank, with a central focusing wheel and right eye dioptre.Turning the nicely machined metal focusing wheel first clockwise, and then anti-clockwise, all the way through its trave,l showed that it was still in excellent working condition, with zero backlash and bumping that one usually encounters with cheaper porro prism binoculars.

As expected from Zeiss, the Jenoptem has a very well made focuser that moves with silky smoothness and with zero backlash.

To begin the cleaning process, I unscrewed the objective housings from the front of the binocular in order to get at the inside surface of the objective lenses, which had a significant amount of grime as well as a small amount of fungal growth. Using a good quality lens brush, I carefully removed much of the dust before using a microfibre lens cleaning cloth soaked in a little Baader Optical Wonder fluid. In just a few minutes I was able to remove the remaining grime on both the outer and inner surfaces of the binocular objectives, as well as the surfaces of the prisms in the rear module of the instrument. The ocular lenses were also given a good cleaning.

The objectives of the Zeiss Jenoptem can be accessed by uncrewing the front of the binocular from the prism and ocular housing.

I was able to verify that the prisms were indeed coated in the same way as the objectives, although I also discovered that the steel clips holding the prisms in place had rusted significantly over time. I did not attempt to clean the clips, as I judged that doing so might throw the instrument out of collimation.

Note the rusted steel clip holding one of the prisms in place, as well as the anti-reflection coating of the second prism(after cleaning).

The objectives on the Jenoptem after cleaning. Note the anti-reflection coatings.

Seen in broad daylight, I was able to verify that the lens coatings had not suffered much in the way of wearing, looking smooth and evenly applied, giving a bluish or purple cast, depending on the angle of view.

The appearance of the objectives in broad daylight after cleaning.

 

And the ocular lenses.

Optical tests:

After screwing the objective modules back into place, I was now ready to begin my optical tests of this older Zeiss binocular. I compared the views served up by this instrument with those garnered by my Barr & Stroud 10 x 50 Sierra roof prism binocular that I use almost exclusively for astronomical viewing. After setting the right eye dioptre on the Zeiss to suit my own eyes, I started with an iphone torch test to assess how the instruments fared in suppressing glare and internal reflections.

The Zeiss 10x 50W Jenoptem(right) and my Barr & Stroud 10x 50 Sierra roof prism binocular(left).

Because the Zeiss does not have the same close focus (~2m) performance as my Barr & Stroud, I had to place my iphone torch several metres away in my hallway in order to get the Zeiss to focus on its light. As usual, the torch was adjusted to its highest (read brightest) setting. Comparing the two in-focus images, I could see that the Zeiss fared considerably worse than the Barr & Stroud. Specifically, it picked up two fairly bright internal reflections, as well as quite a lot of contrast-robbing diffused light, which rendered the Zeiss image considerably less clean and contrasted in comparison to my control binocular. The difference was quite striking!

After dark, I aimed the binoculars at a bright sodium street lamp and again compared the images served up in both instruments. As expected, the Zeiss showed much more in the way of internal reflections, with a lot of diffused light that produced a fog-like veil around the street lamp. The Sierra 10 x 50 in comparison served up a much more ‘punchy’ image with much better control of internal reflections and far less of the foggy, diffused light evidenced in the Zeiss.

Next, I compared the Zeiss and the Barr & Stroud Sierra on a daylight test, examining a tree trunk in the swing park about 80 yards from my front door. Again, the difference between both instruments was striking! Although the image was very sharp in the Zeiss at the centre of the field, it was noticeably dimmer than the Sierra. That diffused light I picked up in the iphone torch test created a foggy veil that significantly reduced its contrast in comparison to the control binocular. I was also able to discern many more low contrast details in the Sierra owing to its ability to gather significantly more light than the older Zeiss. The colour cast presented by both binoculars was also noteworthy. The Zeiss threw up quite a strong yellowish colour cast  to the Sierra, which showed a much more neutral cast in comparison.

Examining the periphery of the same field also showed that the Sierra was exhibiting a larger depth of focus than the Zeiss, which was quite unexpected, as I had been given to understand that porro prism binoculars in general show more depth of focus than their roof prism counterparts. In addition, the Zeiss showed more distortion at the edges of the field than the control binocular.

The Zeiss Jenoptem has very tight eye relief, which I estimated to be just 10mm. The Barr & Stroud Sierra, in contrast, has much more generous eye relief in comparison- 17mm – making it significantly more suitable for eye glass wearers. Indeed, I found it difficult to image the entire field in the Zeiss, having to move my eyeball around to see the field stops.

In summary, these daylight tests clearly showed that the venerable Zeiss was no match optically for the Barr & Stroud 10 x 50 roof prism I had tested it against. The latter was simply in a different league to the former, no question about it!

Handling in the Field:

The Zeiss is rather big and clunky in my small hands and is more difficult to find that optimal position while viewing for extended periods. Weighing more than 200g more than the Sierra, it is also harder to hold steady. The significantly smaller frame of the Sierra roof prism binocular is much easier to negotiate, and is simply more comfortable to use. In addition, the Zeiss has no provision to mount it on a lightweight tripod or monopod, but the Sierra, like most other modern binoculars, does.

Astronomical tests:

Though the weather proved quite unsettled during the week that I tested the Zeiss, I did get a few opportunities to test it out on the night sky. Once again, I used my Barr & Stroud Sierra 10x 50 roof prism as a suitable control. My first target was a bright, waxing gibbous Moon fairly low in the southern sky. The Zeiss threw up more in the way of internal reflections than the Sierra. The colour cast of the lunar surface appeared more yellow in  the Zeiss compared with the cleaner images of the Sierra. As I expected from my iphone torch tests, the sky immediately arround the Moon was also brighter in the Zeiss, with noticeably lower contrast than the Sierra. Moving the Moon to the edge of the field also showed that the Zeiss threw up more distortions than the Sierra control binocular.

Turning to Vega high in the northwest after sunset produced good on-axis images in both binoculars, but when moved to the edge of the field, the Zeiss threw up that little bit more distortion than the Barr & Stroud Sierra. The same was true when I examined the Pleaides and the Hyades in Taurus.

Conclusions and Implications:

The Zeiss Jenoptem was a good binocular in its day but is clearly inferior in almost every sense to the Barr & Stroud roof binocular used in comparison. 40 years ago, the Zenoptem would have set the average factory worker a whole month’s salary to acquire new. In contrast, the Barr & Stroud Sierra can be had for between £100 and £120 in today’s market.  The value of waterproofing was made manifest in the observation of rusting of some of the metal internal components of the Zeiss. The Sierra, in contrast, is fully waterproof, o-ring sealed and purged with dry nitrogen gas to inhibit internal fogging and corrosion of any metallic components used in its construction.

Enormous advances in optical technology over the last four decades, particularly full broadband multi-coatings applied to all lens and prism surfaces, higher quality optical glass, as well as phase coated prisms on the roof binocular, collectively allow very efficient light transmissions to the eye. This is all the more remarkable since roof prism designs usually have many more optical components than their porro prism counterparts.

Better eregonomics in modern roof prism binoculars as well the employment of strong, low mass polycarbonate housings in their design make them lighter and easier to use than their porro prism counterparts from a generation ago. All of these add to the comfort of using them either during the day or at night when looking at the heavens.

I had a look on ebay to see what these old Jenoptems were being offered for. I found quite a few of them selling for between £150 and £200, so not the high prices demanded by other classic binoculars.

Like with all optical firms, time has marched on, with modern binoculars offering much better performance than earlier models.

This comparison test must have implications for many people who already own or use older binoculars and who have not compared them to modern incarnations. And that’s as true for Zeiss as with any other manufacturer. Indeed, I was quite shocked at how much better my first quality roof prism 8 x 42 roof prism binocular fared compared to an old 7x 50 porro I was gifted back in the early 1990s. Technology has well and truly marched on! And while I like classic instruments just as much as the next guy, I see little point in using any when even modest instruments created in the modern age are likely to perform better than similar instruments made a generation ago. It’s just a hard fact of life.

The technology of the past is certainly interesting but it would be daft to neglect the advances offered in the modern era.

 

I would like to extend my thanks to Sandy and his parents for allowing me to test drive these old binoculars. I will be advising him to use lens caps on the optics when not in use and have also provided a sachet of silica gel dessicant to minimise moisture-induced corrosion of the optic.

 

Neil English discusses all manner of classic telescope technology in his 650+ page historical work, Chronicling the Golden Age of Astronomy(Springer-Nature).

 

De Fideli.

In Search of a Good 8 x 32 Binocular.

Two mid-priced 8 x 32 binoculars compared: the Celestron Trailseeker(left) and the Helios LightWing HR( right).

The march of technology continues apace and never ceases to amaze me. This is especially true when it comes to telescope and binocular optics. You can now buy very decent optics at budget prices that display a level of quality we could only dream of a couple of decades ago. And technologies that were only available on premium optics up to fairly recently are now being offered by companies offering much more economical packages to sate the requirements of the masses.

That’s exactly how I feel about my recent foray into binocular testing. Advances in coating technology, in particular, has allowed many new optical firms to offer products that are edging ever closer to the performance levels only available on premium models until recently. Even entry-level roof prism binoculars feature decent anti-reflection coatings on all optical surfaces(which can be as many as 30 in a good roof prism binocular), as well as phase correction technology that significantly increase contrast, accurate colour rendition and image brightness. These less expensive models used either aluminium or silver coatings to boost light transmissions to as high as 80 to 85 per cent, but one can now obtain very economically priced models that also feature super-high reflectivity, broadband dielectric coatings that have increased light transmission to above 90 per cent, in touching distance of the most expensive, premium binoculars money can buy.

Unfortunately, many amateurs who enjoy using quality binoculars mistakenly conflate high-level optical performance with the introduction of extra low dispersion (ED) glass, but the truth is that such an addition contributes little to the quality of the optical experience. Much more significant is the use of higher quality coatings that significantly increase both the brightness and contrast of the images, which in turn enables one to see those finer details, thereby boosting resolution(perhaps this is why the Helios has HR in its name?). Of course, many(but not all) premium binocular manufacturers use a combination of ED glass elements and the finest dielectric coatings, making it all the more difficult for the user to assess the relative importance of either component. But I was able to explore and confirm the dramatic effects of the latter by putting a couple of  mid-priced 8 x 32 compact roof prism binoculars through their paces; a Helios LightWing HR and a Celestron Trailseeker(both pictured above), both of which feature premium quality dielctric coatings on the prism surfaces as well as high-quality broadband anti-reflection coatings on the multiple lenses and prisms used in their construction. Neither instrument contains ED glass elements however. For more on this, check out this short youtube presentation by an experienced glasser and binocular salesman describing one of the models I will be evaluating in this blog(the Helios LightWing),  and who formed the same conclusions as this author.

Both instruments were acquired from the same source, Tring Astronomy Centre. Their friendly and knowledgeable staff have offered exceptional service with a number of past purchases and I had thus no hesitation approaching them again for the acquisition of these 8 x 32 compact binocular models.

The first model I acquired was the Helios LightWing HR 8 x 32, which set me back £127 plus £5 to ensure an expedited delivery of the package within 24 hours of ordering. As soon as it arrived, I inspected the contents, which included the binocular with a rain guard, soft carry case, a lens cloth and generic(read single page instruction sheet) and padded neck strap. Within minutes of its arrival, I had the binocular out of its case to perform my iphone torch test in my living room to see how well an intense beam of white light behaved as it passed through the instrument. As I outlined in a few previous blogs, such a test is extraordinarily sensitive, showing up even the slightest stray reflections in the field of view and revealing how well the optical components suppressed the tendency of the light to diffuse across the field, reducing contrast as it does. Well, to my great relief, the result was excellent! Despite the torch being set at its highest setting in a darkened room, the Helios LightWing HR showed only the feeblest level of ghosting on axis. What is more, there was no difraction spikes or diffused light in the field! The image was exceptionally clean. Indeed, comparing the result to my control binocular, a Barr & Stroud Savannah 8 x 42, which also exhibits exceptional stray light control, the Helios was providing even better results!

To put this in some additional context, the torchlight test result for the Helios 8 x 32 was better than my Zeiss Terra ED 8 x 25 pocket binocular and a Swarovski EL Range 10 x 42, as I recall from my notes!

I now had a new standard by which to measure all other binoculars!

The same was also true when I placed the light beam just outside the field of view. Only a very minimal amount of glare was seen in the field.

The Helios LightWing HR 8x 32 revealed exceptional control of stray light and annoying internal reflections.

Wow!

This told me that the binocular ought to produce very high contrast images in even the most demanding conditions, either by day, glassing in strongly backlit scenes, or at night, when looking at bright light sources, such as artificial street lighting or a bright Moon. No doubt, this is attributed to a variety of factors including excellent multi-layer coatings on all optical surfaces, as well as a sound knowledge of how to adequately baffle the instrument.

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Note to the reader: My pet peeve is seeing excessive glare and strong ghosting from internal reflections in a binocular image. Indeed, I am quite intolerant of it! Moreover, I usually dismiss any reviews that do not test for this phenomenon. Unfortunately, that also entails taking the majority of user reviews I read online with a large dose of salt!

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Examining the Helios, I noted the unusual colour cast of the anti-reflection coatings on both the objective and ocular lenses. They seemed to be immaculately applied! I also noted how the objectives were recessed very deeply; with ~ 10mm of overhang. This is a very good(and often overlooked!) design feature, as it cuts down on peripheral glare during bright daylight observations and also affords considerable protection from dust and rain.

The unusual colour cast of the anti-reflection coatings of the Helios LightWing objective lenses.

Mechanical assessment: The Helios is very well constructed. The chassis is fabricated from a magnesium alloy which combines light weight(500g) with good mechanical strength. This is an unsual offering in such a low-cost instrument, with cheaper polycarbonate or even ABS plastic being the rule rather than the exception on models offered at this price point. The central hinge had enough tension to maintain my particular IPD but I would have liked it to be just a little bit stiffer(just like my wonderful Barr & Stroud Savannah 8 x 42). I found handling the binocular to be unusually tricky, as the rubber eyes needed to attach the neckstrap protrude from the barrels a little too much, making it rather more awkward to get the binocular comfortably placed in my hands while observing.

The focus wheel is very large in relation to the overall size of the instrument. Indeed, I thought it was a little too large! Although I could get a good grip, rotating it showed that it was somewhat clunky and offered unusual resistance to movement. In contrast, the dioptre ring moved with silky smoothness, and you can actually see the right ocular field lens moving as you rotate it!

The buttery smooth right-barrel dioptre ring is a joy to adjust.

The eyecups are rather stiff but do extend upwards with two clickstops. With an eye relief of 15.6mm, eyeglass wearers will find it difficult to image the entire field. Fortunately for me though, this wasn’t a problem, as I don’t wear eye glasses while glassing. The cups are made from quality metal covered by a soft rubber-like material. They are very firm and hold their positions securely even when undue pressure is applied to them. Overall, a very nice touch!

The chassis is covered by a rather thin rubberised skin, which was somewhat thinner than I’ve seen on a variety of other binoculars I’ve sampled. As a result, it has slightly less friction while man handling, which can prove important, especially if used for prolonged periods in the field. It also means that it would wear down that little bit faster after extended use.

The Helios can be attached to a tripod or monopod for increased stability via the built-in bush located between the barrels, toward the front of the instrument.

Optical daylight testing: Scanning some autumn leaves in my back garden confirmed what I had witnessed in the torchlight test. The image was very bright and tack sharp with wonderful contrast and colour fidelity. There was nary a trace of chromatic aberration( which continues to affirm my belief that ED glass is unnecessary: -a marketing gimmick? – for such small, low power binoculars). However, this was only true in the central 50 per cent of the field. The outer part of the field became progressively softer with the edge being out of focus. Examining a telephone pole about 25 yards in the distance unveiled very strong field curvature as it was moved from the centre to the edge of the field of view.

I hit another snag when I attempted to image the Fintry hills about a mile in the distance. The focus wheel was racked to the end of its natural focus travel but I still could not quite reach a sharp focus. Adjusting the dioptre ring on the right barrel allowed me to just get there but the left barrel was still not sharply focused. After dark, I did a test on the bright star Vega, which unfortunately confirmed my daylight tests. Although I could achieve pinpoint sharp images in the right barrel, the left barrel showed that the star was badly bloated. Another test on the Moon showed the same thing. The right barrel gave a razor sharp image with exceptional contrast and no internal reflections or diffused light around it, but the image at the edge was badly out of focus.

The whole experience left me somewhat bewildered. Why expend so much effort into applying state-of-the art coatings into a binocular with nice mechanical features, only to see excessive field curvature in the outer part of the field? It just didn’t make sense! I mean, Helios could have made the field a little smaller(it has a true field of 7.8 degrees) with sharper edge definition and I would have been happy.  In reallity you see, I had been spoiled by the nearly flat fields presented by my Barr & Stroud Savannah 8 x 42(and over a larger field to boot- 8.2 degrees), as well as those presented by my Zeiss Terra pocket and my other models with aspherical ocular lenses. Needless to say I was disappointed and decided to contact the staff at Tring the same evening, explaining my findings.

Next morning, they contacted me, apologising for the defective optic, as well as suggesting that I could have a replacement Helios LightWing, or try a Celestron Trailseeker 8 x 32, which apparently had very similar specifications to the former. Now, I had a bad experience with an 8 x 25 Celestron Nature DX(an entry-level roof prism binocular) which showed far too much glare and internal reflections for my liking. But I had a good look at the specifications on the Celestron Trailseeker models, which were recently discounted by 20 per cent and were now being offered at the same price as I had paid for the Helios LightWing. After some deliberation, I decided to accept their offer of trying the Trailseeker. And to their credit, Tring shipped out the binocular, together with a return label for the Helios, the same day, and I received it less than 24 hours later!

How about that for customer service!

The Celestron Trailseeker 8 x 32 package.

With some trepidation, I opened the package and inspected its contents. First impressions looked good. I received the binocular, a much higher quality carry case, a binocular harness, tethered rubber objective caps and rain guard, a decent quality padded neck strap, a lens cleaning cloth and a comprehensive instruction manual dedicated to the Trailseeker  line of binoculars( in five languages).

The Trailseeker binocular specifications looked very similar to the Helios, which included the application of premium-quality phase and dielectric coatings, a 7.8 degree field (136m @1000m), Bak-4 prisms, o-ring sealed, dry nitrogen purged, making it fog proof and water proof(though to what extent was not revealed). And just like the Helios, the Trailseeker can be mounted on a tripod or monopod.

As with the Helios, the Trailseeker has very deeply recessed objectives (again about 10mm) but the anti-reflection coatings looked different in daylight;

The Trailseeker also has deeply recessed objective lenses but the coatings appeared different.

Just like the Helios, the Celestron Trailseeker has a rugged magnesium alloy chassis but the focus wheel is significantly smaller. Weighing in at just 450g, it is 50g less bulky than the Helios. The Trailseeker build quality is excellent; rugged, much easier to handle than the Helios and overall having better ergonomics. The tough, rubberised covering has better grip than the Helios too, and small thumb indentations on the belly of the instrument makes it that little bit more comfortable to hold in the hand.

Nicely placed thumb indents on the underside of the Trailseeker make handling that little bit more intuitive.

Well, you can guess what I did next; yep, I set up my iphone torch, turned it up to its brightest setting and placed it in the corner of my living room with the curtains pulled to cut off much of the daylight. With a good close focus of about 6.5 feet, eagerly I aimed the Trailseeker binocular at the light and examined the image.

Drum roll……………………………………….

An excellent result! Internal reflections were minimal, diffused glare was all but absent and diffraction spikes were very subdued. Comparing the Trailseeker to my Barr & Stroud Savannah 8x 42 control binocular showed that it was on par with it. What a relief! To be honest, I had some reservations about the Celestron, owing to my unfavourable experience with the cheaper Nature DX model, and so I half expected that they might skimp on this important process. But no, they did a very good job! So far, so very good!

I was also impressed with the mechanical attributes of the Trailseeker, which is difficult to ascertain vicariously without man handling it. Though quite conservative in design, the eyecups are of high quality(metal over rubber) but have a nice feel about them. They twist up much more easily than those on the Helios and have two settings. Like the Helios, the eye relief is pretty tight(15.6mm) for eye glass wearers but is plenty good enough for those who observe without glasses.They do not budge even when considerable force is applied to them. I would rate their quality as very high, so much so that I don’t think I will have much in the way of problems with them going forward.

The metal-over rubber eyecups of the Celestron Trailseeker are a good step up from the Nature DX models and feel very secure while glassing.

The focus wheel has a ‘plasticky’ feel about it but unlike the Helios, infinity focus does not lie at the extreme end of the focus travel. This is actually useful for ‘focusing out’ some of the aberrations at the extreme edge of the field. Unlike other user reviews of the Trailseeker, the focus wheel on the unit I received was quite stiff to operate out of the box but this will surely loosen up with more use. Rotating the focuser both clockwise and anti-clockwise revealed little or no backlash or bumpy spots that you often encounter on cheaper binoculars. Some users balk at the idea of using a plastic focuser but I cannot for the life of me understand why it would make much difference. I mean, if it works, it works! What’s to give?

The focus wheel on the Trailseeker is nothing out of the ordinary but does work well in field use.

The dioptre ring is located under the right eyecup. It rotates smoothly with just the right amount of friction.

Optical daylight testing: As I’ve illustrated above, good mechanical design and great control of stray light don’t count for much if the images don’t deliver. So I was eager to see how the Celestron Trailseeker behaved when looking ’round the landscape. Accordingly, I examined the same autumn leaves in my back garden set a few tens of yards away. This time, the results were very much more encouraging! The leaves focused beautifully, throwing up excellent brightness, contrast and sharpness with a much wider sweet spot than in the Helios, which I estimated to be about 70 per cent of the field.  I could immediately tell that there was much less field curvature in this binocular than in the Helios, allowing me to sharpen up the edge of field definition with only minor tweaking of the focus. This much reduced field curvature was also apparent when I examined the same telephone poll I observed with the Helios. Instead of the strong off-axis distortions I encountered with that instrument, as the pole was moved from the centre to the periphery of the field, the Trailseeker proved much more forgiving.

What a relief!

Having said all of this, there was more off-axis field curvature in the Trailseeker than in my Barr & Stroud Savannah 8 x 42, which, in comparison, throws up a wider and flatter field nearly all the way to the edge. As I’ve said many times before, the Savannah is a phenomenal operator given its very modest price tag. Perhaps some of the drooling gayponauts reading this blog right now could get off their fat backsides and confirm it!

Nah, probably too much to ask!

The Barr & Stroud Savannah 8 x 42 wide-angle binocular; an existential threat to the hubris of thieving gayponauts.

Nightime testing:

After dark, the Trailseeker delivered excellent results on artificial street lights, just as my torchlight tests reliably anticipated. There was no annoying glare, internal reflections and the diffraction spikes were small and very subdued. Turning the instrument on a low Moon skirting the horizon showed wonderful sharpness on axis, with well above average contrast. And when I placed the Moon at the edge of the field, it remained quite sharp, though visibly softened by a small amount of field curvature. Needless to say, it was in a completely different league to the Helios in this regard!

Later in the night, with the Moon having set, I examined the appearance of the large and sprawling Alpha Persei Association located nearly overhead at the time. This provided an excellent test of how its many bright stellar members would behave from the centre of the binocular field to the field stop. To my relief, the stars remained acceptably small and sharp across the entire field, with the stars at the edge of the field requiring only a small tweak in focus to improve their definition. They did not balloon to stupidly large sizes like I observed in the Helios.

Turning the binocular on the Hyades in Taurus gave very pleasing results too. Contrast was excellent with its many colourful stellar components remaining acceptably small and crisp even at the edges of the field.

I considered these results to be very acceptable. This is one small binocular that can be used profitably for nightime observations!

A Walk in the Countryside with the Celestron Trailseeker 8 x 32

Although the Celestron Trailseeker 8 x 32 is a small, high-quality and lightweight instrument, it is not readily pocketable, unless you have a coat that has rather large and deep receptacles. Having tried a few 8 x 32 binoculars, I personally find them a little awkward to use in comparison to my two favourite pocket binoculars like my Opticron Aspheric LE and my Zeiss Terra(both of which are 8 x 25 formats) or a larger instrument such as my 8 x 42. I just find the 8 x 32 format a bit kludgy in my rather small hands. That said, the 8 x 32 seems to be a popular choice for birders and other nature enthusiasts, who tire of schlepping around a larger instrument for hours on end. In good light, there’s no real advantage in using a larger format binocular and so I tend to use my pocket binos most often. But if you are observing in low light conditions, such as a dull, overcast winter day, late in the evening or early in the morning, the 8 x 32 would definitely be a better choice. I have verified this wisdom by comparing the views through my  8 x 25 Terra and the 8 x 32 Trailseeker at dusk, where the brighter images served up by the latter are plainly in evidence. And because you have a relative abundance of good quality light to play with, you can see more details in the image. Shimples!

Choosing a small binocular is a deeply personal choice that you can only decide on after trying them in the field.

The consensus view is that larger binoculars are more comfortable to use since their larger ocular lenses make it easier to place your eyes in the correct position to see and immerse yourself in the field of view. I believe there is definitely some truth in this, but in the end it’s really about what you get used to. I personally have no trouble lining up my eyes with the smaller eye lenses on my pocket binos, so I never see this as being much of an issue.

Enjoying the rich colours of autumn on a hill walk overlooking Fintry.

All that having been said, the Trailseeker 8 x 32 is a very handy companion on my daily two-mile ramble ’round Culcreuch Castle Estate, which has some extensive wooded areas, a fast-flowing river, numerous small brooks, open fields which extend towards the surrounding hills and a small pond, where I enjoy watching the antics of a variety of water-loving avian species. The field of view is very generous at 7.8 degrees, which is quite large as most 8 x 32 binoculars go, though some models sport still larger fields in excess of 8( ~ >140m@1000m) angular degrees. The razor sharp optics on the Trailseeker has given me many wonderful views of golden autumn leaves glistening in weak November sunshine. I especially love to stand under a tree and glass the branches above me, focusing in on their wondrously complex contours. The low autumn Sun this time of year illumines the trunks of the trees in the wooded areas around the estate, highlighting the wonderful texture of the tree bark and the play of light upon the lichens and mosses that live symbiotically with it.

If time is not against me, sometimes I like to stop and focus in on a stretch of water flowing from the numerous small streams that feed into the Endrick, imaging the contours of rocks laden with fallen leaves and closing in on the foamy organic bubbles that swarm along the fast-flowing stretches. And when the Sun shines on the water, I can feast my eyes on the beautiful and intense reflections emanating from its surface. This is where glare control is paramount, as even a small amount of light leakage can ruin an otherwise compelling binocular scene.

Binoculars have come a very long way since their founding days. I find it amazing that one can acquire quality optics and durable mechanics like this at such keen prices. The Celestron Trailseeker 8 x 32 has been a very pleasant surprise, combining wonderful ergonomics with state-of-the-art optical science. I think a lot of people will enjoy it.  And now that its price has come down significantly, this is a good time to grab yourself a real bargain and enjoy the wonders of nature up close and deeply personal.

Just in case……………..

 

Thanks for reading!

 

Neil English has fallen in love with what binoculars have revealed to him, and is seriously thinking of compiling a larger portfolio of  binocular experiences for a future book-length treatise on their various applications.

 

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. Streches 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 unturn reveals even more of God’s Creation. A scurrying earwig, a wondrously armoured wood louse or a frollicking 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 birdwatching, 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 10:25pm 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!

De Fideli.

Product Review: The Opticron Aspheric LE WP 8 x 25 Pocket Binocular.

A fine compact binocular at a fair price.

Tiny little pocket binoculars have grown on me.They can be supremely useful to those who value or need ultra-portability, when larger binoculars simply are unworkable. Their tiny size ensures that they can be carried in a pocket or a small pouch, where they can accompnay hikers, hunters, sports enthusiasts, bird watchers and nature lovers who delight in seeing the full glory of God’s created order. Frustrated by a lack of any credible reviews of a variety of models, I began a ‘search out and test ‘ program that would teach me to select models that offered good optical and mechanical performance, as well as good value for money.  As you may appreciate, this was far easier said than done, but in the end, I did find a model that I could trust to deliver the readies; enter the Opticron Aspheric LE WP 8x 25 binocular.

Retailing for between £120 and £130 ( ~$175 US), the little Opticron pocket binocular didn’t come cheap. But good optics and mechanics are worth having, especially if the user intends to employ the instrument on a regular basis. As I explained, I chose this model based on the performance of a first generation Opticron Aspheric that I had purchased some time ago for my wife, possessing identical optical specifications to this newer model, but without having the additional advantage of being nitrogen purged, as well as being water and fog proof. In truth, I chose the original model without much in the way of research and with very little experience of what the market offered; Opticron is a good make, trusted by many enthusiasts for delivering good optical performance at a fair price.

Opticron began trading back in 1970, founded as a small British family firm, and offering binoculars, spotting scopes and other related sports optics for the nature enthusiast. Since those founding days, Opticron has continued to innovate, where it now is a major player in this competitive market, offering well made products catering for the budgets of both novices and discerning veterans alike. And while some of their less expensive models are made in China, many of their high-end products are still assembled in Japan.

What you get.

What your cash buys you: The Opticron was purchased from Tring Astronomy Centre. It arrived double-boxed and with no evidence of damage in transit. You get the binocular with both ocular and objective covers, a high quality neoprene padded case, a comprehensive instruction manual & warranty card. The details of that all-important warranty are shown below:

Details of the warranty.

After a few days of intensive testing I was satisfied that I had received a high quality instrument and so I elected to register my binocular on the Opticron website.Owners are not obligated to register the instrument in this way however, as all that is required is proof of purchase, should any issue arise with the instrument in normal use.

Binocular Mechanics: The Optricron Aspheric LE WP 8 x 25 is a classically designed pocket binocular with a double-hinge designed allowing the instrument to fold up into a very small size that can be held in the palm of your hand. The hinges have just the right amount of tension, opening up and holding their position even if held with one hand.

The focuser is slightly larger than the first-generation model, and has better grip, allowing you to use it even while wearing gloves. The barrels and bridge of the binocular are made from aluminium, overlaid with a tough, protective rubberised armouring. Compared to the first-generation model,  the new incarnation induces more friction with your fingers, an important feature if it is to be used for extended periods of time.

The New Opticron Aspheric LE is now water and fog proof.

Initially, I found that turning the focuser to be a bit on the stiff side, but after a few days of frequent use, I became used to it. Turning the focuser either clockwise or anticlockwise showed that there was no backlash, moving smoothly in either direction. The instrument has an integrated neoprene lanyard which can be wound up around the bridge while being stored in its case. I very much like this rather understated feature, as there is no need to fiddle about attaching a strap. Out of the box, it’s ready to use!

Using the Optricon Aspheric LE WP is child’s play; just twist up the eyecups and they click into place. There are no intermediate settings. If you wear glasses, leave the eyecups down.

The twist-up eyecups have a soft rubberised overcoat which are supremely comfortable on the eyes. There are just two positions; fully down or fully up. Once twisted up, the cups lock in place and rigidly stay in place with a click. Eye relief is very generous(16mm), allowing eye glass wearers to engage with the entire field. I don’t use glasses while observing through binoculars, so I always pop the eyecups up while viewing through them. Optimal eye placement is very easy to find quickly, thanks to the large field lens, with none of the annoying blackouts I experienced on a few lesser models.

The dioptre setting is located in a sensible place; right under the right eyecup. A small and very elegantly designed protruding lever on the dioptre ring makes it very easy to rotate either clockwise or anti-clockwise. It works well and stays in place even after repeatedly removing the instrument in and out of its small carry case.

An elegant design feature; a small protruding lever under the right eyecup makes it easy to adjust the dioptre setting.

I measured the interpupillary(IPD) range to be between 32 and 75mm, ample enough to accommodate most any individual. Moreover, the well designed dual hinges on the bridge ensure that once deployed they stay in place with little or no need to micro-adjust while in use. The Opticron pocket binocular weighs in at just over 290 grams.

If the Opticron Aspheric pocket binocular were a car, it would surely be an Aston Martin.

Optical Assessment: Although this tiny binocular does not have a stalk to allow it to be mated to a monopod or tripod, I was able to assess how well collimated it was by resting the binocular on a high fence, and examining the images of a rooftop some 100 yards in the distance, checking to see that the images in the individual barrels were correlated both horizontally and vertically. This was sufficient to affirm that the binocular was indeed well collimated.

During daylight hours, the binocular delivers very bright and colour-pure images thanks to a well made optical system which includes properly applied multi-coatings on all optical surfaces, good baffling aginst stray light and silver coated prisms(boosting light transmission to 95-98 per cent). The binocular also has correctly executed phase coatings on the prisms to assure that as much light as possible reaches the eye. Sharpness is excellent across the vast majority of the field, with the aspherical optics minimising off-axis aberrations including pincushion distortion and field curvature. I wouldn’t be surprised if the overall light transmission is of the order of 80 to 85 per cent(revised in light of the tranmissitivity of the Zeiss Terra ED pocket glass with a light tranmsission of 88 per cent).

One of my pet peeves is seeing glare in the image when the binocular is pointed at a strongly backlit scene. I was delighted to see that apart from very slight crescent glare  when pointed near the Sun, the images generally remained stark and beautifully contrasted. These good impressions were also confirmed by more stringent tests conducted indoors by aiming the pocket binocular at my iphone torch set to its maximum  brightness. These tests showed that although there was some weak internal reflections  and flare, they were well within what I would consider acceptable. At night, I was able to see that when the binocular was aimed at some bright sodium street lamps, only very slight ghosting was evident. Finally, aiming the 8 x 25 at a bright full Moon revealed lovely clean images devoid of any on axis flaring and internal reflections. Placing the Moon just outside the field did show up some flaring however, but I deeemed the result perfectly acceptable. You can chalk it down that these results are excellent, especially considering the modest pricing of the instrument.

Colour correction was very well controlled in both daylight and nightime tests on a bright Moon. On axis, it is very difficult to see any chromatic aberration but does become easier to see as the target is moved off axis. That said, secondary spectrum was minimal even in my most demanding tests, affirming my belief that a well-made achromatic binocular can deliver crisp, pristine images rich in contrast and resolution.

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An interesting aside: My former colleague at Astronomy Now, Ade Ashford, reviewed a larger Opticron binocular- the Oregon 20 x 80 – for the October 2019 issue of the magazine. In that review, featured on pages 90 through 94, he confirmed what I had previously stated about larger binoculars with powers up to 20x or so; there is no need to use ED glass if the binocular is properly made and this goes for both daylight viewing and nightime observations. Below is Ashford’s assessment of the 20 x 80’s daylight performance:

And here are his conclusions:

Moreover, Ashford offers this sterling advice to the binocular enthusiast:

” …..don’t get hung-up on ED glass instruments. A well-engineered achromatic model will perform well, particularly if it uses Bak-4 prisms and its optical surfaces are multi-coated throughout.”

pp 91

Having ED glass counts for nothing if the binocular is not properly made. I would much rather have a well made achromatic instrument than have a poorly constructed model with super duper objective lens elements.

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A fine quality pocket binocular in the plam of your hand.

My Little Aston Martin:

The little Opticron has already accompanied me on a few hill walks, a Partick Thistle FC( sad, I know!) testimonial and numerous rambles near my rural home, where it has delivered wonderful crisp images that never fail to delight. The field of view(5.2 degrees) is a little on the narrow side as pocket binoculars go, but its plenty wide enough for most applications and besides, the distortion free images nearly from edge to edge quickly override any perceived handicap of having a restricted viewing field.

Its tiny size and lack of garish colouring make it the ideal instrument to bring along to sports events, where it doesn’t attract attention from fellow crowd members. The Opticron is also a most excellent instrument to examine colourful flowers, butterflies and other marvels of nature near at hand, thanks to its excellent close focus; measured to be ~51 inches.And because its waterproof, it would also make an excellent companion while sailing or fishing.

The Opticron pocket binocular comes with a very high quality padded pouch to protect the instrument from any kind of rough handling.

Of course, the power of a small, high-quality pocket binocular quickly dwindles as the light begins to fade in the evening, or during the attenuated light before dawn, where a larger field glass really comes into its own. A little pocket binocular like this is far from the ideal instrument for viewing the night sky, but it can still be used for the odd look at the Moon, a starry skyscape or brightly lit cityscape.

I consider weatherproofing to be a sensible and worthwhile addition to any binocular and is certainly welcome on this second generation Opticron Aspheric. The instrument is purged with dry nitrogen gas at a pressure slightly higher than atmospheric pressure. This positive pressure helps to keep out dust and marauding fungi, and the sensibly inert nature of nitrogen ensures that internal components(including the silver coated prisms), will not tarnish or oxidise any time soon. This will only serve to increase the longevity and versatility of the binocular in adverse weather conditions, especially in my rather damp, humid climate. When not in use, I have taken to storing all my binoculars in a cool ( ~60 F) pantry with silica gel dessicant inside their cases. Yep, all my instruments are in it for the long haul.

Quality you can wear.

The Opticron Aspheric LE WP 8 x 25 is an excellent example of how a well made, achromatic binocular can deliver wonderful, sharp and high-contrast images. It is more expensive than many other pocket binoculars, but you most certainly get what you pay for.

 Thanks for reading!

Neil English’s new title, The ShortTube 80; A User’s Guide, will hit the bookshelves in early November 2019.

 

De Fideli.

N=2: Why I’m the Very Proud User of a Barr & Stroud Savannah 8 x 42 Binocular.

An alpha binocular in many ways, except for the price.

Semptember 9, 2019

I’ve said it before, and I’ll say it again: there is something in a name.

In my ongoing investigation into binoculars, I’ve discovered that, like telescopes, you don’t always get what you pay for. In particular, if a product offers advanced optical features like a full multi-coating on all air to glass surfaces, ED elements, or phase corrected roof prisms, it doesn’t necessarily translate into a solidly functioning optic. I’ve tested products purported to have premium optics but upon inspection, did not deliver all the goodness that they were promising in cleverly devised youtube promos and fancy specification sheets etc.

One company that has bucked this trend is Barr & Stroud, a once prestigious optical and engineering firm, established in Glasgow, Scotland, that at one time supplied all manner of optical instruments to the British navy during two world wars. Like many other large optical firms established in Britain, it underwent considerable re-structuring over the decades. Today, the brand name is owned by Optical Vision Limited(OVL) and began producing binoculars for the civilian market in 2011, moving production to China.

My enthusiasm for the brand began just a year ago(2018), when I initiated testing a variety of their binoculars in different price ranges. Like many others who have looked through their instruments, I was duly impressed by the incredible bang for buck of their offerings, with optics that punched well above their modest price tags.

Of particular note is the Barr & Stroud Savannah 8 x 42, which delivered wonderful, wide-field, high-contrast and colour pure images of the Creation. Unlike other brands in the same price range, which offered so-so performance, especially off-axis, these binoculars maintained excellent control of the same aberrations. The massive 8.2 degree field of these 8x glasses is sharp across the vast majority of the field, with only the extreme edges showing significant distortion.

My first Savannah was actually purchased on the second-hand market, and that out of sheer curiosity. Expecting such a wide angle binocular to show average optical quality as one moves off axis(like so many others I’ve tested), I was very pleasantly surprised to discover that this excellent image quality was being maintained to the extreme edge of the field. Indeed, the view, in retrospect, was almost too good to be true. Unfortunately, the dioptre ring, which is situated in a very unusual place on this binocular (just ahead of the large focus wheel) developed a fault, which necessitated its return to OVL for repair. What I actually received was a brand-new instrument and so I was able to asess the performance of two samples of the Barr & Stroud Savannah that inspired the writing of this blog.

Two great performers: the Barr & Stroud 8 x 42 Savannah(left) and the 10 x 50 Sierra(right).

Built like a proverbial tank, the fully weatherproof and nitrogen purged Savannah 8 x 42 is heavier than many competing models on the market. Indeed, at 819 grams, it even weighs more than my 10 x 50 Barr & Stroud Sierra binocular (which also delivers excellent optics and mechanics for the buck). Outwardly, the Savannah has a rather Spartan look and feel about it, with features that are simple and rather understated. The eye cups are of very high quality, which can be set to three positions, and with a very generous 18mm eye relief, is ideal for eye glass wearers and those who like to observe without glasses. When twisted up, they click into place with a reassuringly loud “thwack” sound, and which remain in that position even after excess pressure is applied. Indeed, I rate these eyecups very highly and amongst the best that I have sampled thus far in my binocular education.

The high quality multi-coatings on the 42mm objective lenses of the Savannah. The reader will also note how deeply recessed the objectives are. This helps suppress glare in bright, daylight conditions.

The focus wheel is large and moves smoothly without any stiction, either clockwise or anti-clockwise, making it easy to change the position of best focus from as close as 2 metres to beyond infinity. The tension is just right; not too stiff and not too slack.

All the accessories that come with the Savannah are of high quality; including a hard black clamshell case, a padded neck strap with the B&S logo and rubber objective and eyepiece lens caps that can be affixed to the binocular and so are not easily lost in routine field use. The instrument also comes with the company’s 10-year warranty.

The large and responsive focus wheel on the Barr & Stroud Savannah 8 x 42.

The new binocular turned out to be every bit as good optically than the first one I returned! Indeed, it could even be that little bit better! Images are bright and razor sharp, rich in contrast and colour pure. Though it contains no ED elements, the instrument shows only a trace of chromatic aberration, and only if you go looking hard for it. Like I said before, I don’t consider the presence of ED glass as a feature that is necessary on binoculars of this specification. Crank up the power nearer to the resolving magnification, and it’s a different story. But in this realm, what I’m more interested in, and which is far more important in the scheme of things, is how well the binocular is put together.

Roofs are complex instruments, requiring engineering skill and very careful assembly of the components. Some firms know how to do it well, others don’t…..methinks.

The high quality twist up eyecups on the Savannah click securely into place with a loud “thwack” sound. Note the tough, texturised rubber amouring covering the instrument.

My assessment of binocular optics involves the usual procedures employed by other reviewers, but I have also devised much more demanding tests to learn how well the light is being transmitted though the optical train.  What I have discovered is that many purportedly high-end roof prism binoculars (based solely on their recommended retail price) often show considerable flaring and annoying internal reflections when observing strongly backlit daylight scenes. In addition, night time testing on bright artificial street lights and the full Moon also provide solid clues as to what is going on inside the test binocular(which unfortunately, are all hermetically sealed!!).

One particularly stringent test is to direct an intensely bright beam of light from my iphone into the binocular to see how it deals with glare and internal reflections. No roof prism binocular, no matter how well made, can completely pass these tests;

All fall short:- but what astonished me was how well they were suppressed in the Savannah 8 x 42. Unlike many other models, which reveal too much glare and bright ghosting across the field, both my 10 x 50 and 8 x 42 Barr & Stroud instruments came out with truly excellent results! In particular, the degree of glare suppression and control of internal reflections present in the Savannah was fully the equal of a world class binocular: – in this case, the Swarovski 10 x 42 EL Range:. Where you will often pick up diffraction spikes and flaring from bright street lighting in an inferior instrument, as well as contrast-robbing diffused light around such artificial light sources (not to mention internal reflections), my new Savannah 8 x 42 shows up very little. This is easily seen in regular daylight testing, where the images thrown up by the instrument show very high contrast, allowing very fine details to be easily discerned.

Performing a small, bright light test in the comfort of my living room. Note the small amount of daylight left in the room to asist imaging objects immediately behind and around the light source(my iphone torch).

I thought long and hard about why such an economical instrument offered such unreasonably excellent control of stray light, and then I remembered how the same company made high-quality optical instruments for the British navy. Out at sea, where sunlight is strongly reflected off the water, glare suppression would have been a high priority for any optic used for long distance surveillance. Although it remains an interesting conjecture on my part, it could be that the technicians who assemble such binoculars have specialised knowledge on how to keep those internal light leaks at bay. Afterall, once upon a time, not doing so might well have made all the difference between life and death!

Some important details coming through on the focussing wheel. The ocular lenses are hard coated for extra durability.

Whatever the reasons for such optical excellence, the wonderful colour correction, contrast and suppression of stray light make the 8 x 42 Savannah binocular an excellent choice for birders and naturalists. I cannot think of a better instrument – without dropping an additional few grand – to take along with me to observe the deluge of autumnal colours that are only just emerging, as the trees shut down for a long, winter nap. But, as I’ve discovered, the 8 x 42 also delivers knock-out views of the celestial realm!

As I recall, it was with some trepidation that I decided to try the Savannah. I was leary of the advertised field of view -143m@1000m or 8.2 angular degrees. I had learned of other binoculars delivering such enormous fields of view but having disappointing off-axis performance. Better to have a binocular that delivers a smaller field of view with tightly focused stars near the edge than suffer the indignation of seeing those stars swell up in the outer part of the field. It’s just not tennis!

But my fears were completely allayed once I tried them out on the night sky.  I was literally blown away! Not only was the field of view enormous, but it was very well corrected, right to the edge of the field. Believe me, I have experienced some real howlers, where stars are pinpoint sharp in the centre of the field but when moved off axis, the same test stars balloon into enormous blobs when positioned near the field stop. Starfields remain crisp throughout the field of the Savannah binocular making it an excellent choice for casual star gazing.

Although the binocular can be mounted on a monopod for increased stability, I have rarely used it in this capcaity. Instead, I enjoy hand-holding the instrument where the 8x magnification makes it considerably easier to hold steady over a 10x instrument. That said, if I wish to push the instrument to see the very faintest stars, a monopod is a good way to go. Some binocular authorities I have read suggest that you can gain up to 1 stellar magnitude deeper if the image is stabilised.

The very well corrected, ultra-wide field of the Barr & Stroud Savannah  8 x 42  provides stunning views of large clusters of stars. For example, it provides knock-out views of Melotte 20, otherwise known as the Alpha Persei Association, where the field is littered with several dozen hot, white stars varying in glory from the third to the 10th magnitude. But perhaps my fondest night time experience with this wonder binocular was seeing the entire Sword-Handle and Belt stars of Orion in the same field on a cold, dark December evening.  And where my 10 x 50 Sierra binocular can just frame the Hyades, the Savannah frames the same picturesque asterism with plenty of room to spare!

The large, sensibly flat field of the Savannah has proven excellent for watching meteor showers. I just aim it at the radiant and watch to see if some shooting stars flash across the field. I also love exploring the interface between land and sky. Indeed, as described in this blog, the Savannah is my instrument of choice to explore Moon and starscapes rising above trees and buildings near my home. The Savannah has re-kinded my interest in observing the full Moon when the clouds pass over it. I adore the play of light and colour the binocular serves up in its enormous field of view.

The 8 x 42 is always by my side while using my backyard telescopes. It has greatly increased the speed and efficiency of finding faint fuzzies. Once I locate the target with the binocular, the telescope is pointed at the same spot of sky where I can rapidly hone in on the object.

A binocular that doesn’t want to go inside its hard case.

Readers will forgive my rather vaunted praise of this amazing instrument. But I feel it is justified. In an age of con artists and let downs, this instrument is nothing short of a ray of sunshine. It offers exceptional value for money and has sated my desire to acquire anything else in this mid-sized binocular class. I can hand-on-heart recommend it to other observers looking for an excellent all-round binocular for day and night time use. You’ll not be disappointed!

Thank you for reading!

 

Neil English is the author of several books in amateur and professional astronomy.

 

 

De Fideli.