August 30 2019
Pocket binoculars are a popular choice for many birders, hikers, ramblers and all-round nature lovers who want to get up-close and personal with God’s illustrious creation. If you have scenery like this right on your door step, trust me, you’ll be keen to take along some binoculars to enhance and extend what your eyes can see;
A pocket binocular usually has objective lenses less than 30mm in diameter and offer magnifications anywhere from 7x to 10x. They are small and in general fit inside a pocket, giving rise to their name. Like all other binoculars, pocket glasses come in a range of prices, starting from just a few tens of pounds right up to £1000, depending on the make and model. The cheapest models are to be generally avoided, as they often have very shoddy optics and/or mechanics, but things get very interesting once you move into the mid-priced market, where you can acquire decent optics and mechanics for prices anywhere from £70 up to a few hundred pounds. But is buying a pocket binocular from a reputable optics firm a sure way to get decent quality? I’m going to have to concede that the answer is “no.”
That’s based on my experiences mainly with two models from the well established companies: Bresser(Germany) and Kowa(Japan). Both models were acquired from amazon and possess similar optical specifications, the Bresser Pirsch 8 x 26mm and the Kowa SV 8 x 25mm DCF, which set me back £97.00 and £83.00, respectively. Both models are roof prism designs, have fully multi-coated optics and phase corrected prisms to maximise the amount of light that is transmitted to the eye, and to render colour-true images in bright daylight conditions.
The Bresser Pirsch 8 x 26mm was exciting to unpack, as it looked the bizz from the online images and the specifications promising “premium quality worthy of their prestigious lifetime warranty.” And when I opened up the case to have a look at the binocular, I must admit to being instantly impressed; here was a stylish looking instrument with a beautifully made, ‘Swarovski like’ open bridge design. The focuser was large and constructed from high quality metal. In operation, it was a joy to use, moving with silky smoothness, with no stiction when turned clockwise and anti-clockwise through its travel.
All the accessories were of high quality, which included a padded next strap, an oversized nylon case, instruction manual, rubber objective and eyepiece covers, and a lens cleaning cloth.
The twist up eyecups are amongst the best I have encountered, clicking through a number of stages from fully retracted to fully extended.They hold their positions very well, even when significant pressure is applied to them. The dioptre setting is situated in a sensible place; just under the right barrel. It is stiff and once set in place it will not easily budge.
Handling this binocular was particularly pleasurable, as the open bridge design allows for firm gripping either with or without gloves, and can easily be focused using one or two hands. The binocular is lighter than it looks: ~ 290 grams
But mechanics are only half the story of any binocular. How did the optics fare?
Collimation was tested by mounting the binocular securely on a monopod that was firmly sandwiched in place between two planks of wood on my garden fence, and examining the fields of view presented by both barrels of the instrument. This showed that the binocular was indeed well collimated, certainly within factory tolerances. I had no trouble instantly merging the images once the optimum IPD was selected. Close focus was estimated at about 6.5 feet, in line with the stated specifications. So far so good.
The quoted eye relief for the Pirsch binocular is 15.6mm. That should have been plenty good for eye glass wearers. However, I found that only by pressing my glasses hard against my eyes could I observe the full field. It was not comfortable and so I think folk that have to use eye glasses when using this binocular will struggle.
True to the specifications, the binocular offers a fairly wide field of view. I measured it as about 6.6 degrees(in agreement with its stated FOV of 117m@1000m). Compared with an entry level test binocular with no phase coating(but with fully multicoated optics), the image was better corrected for seidel aberrations across the field of view, revealing noticeably less field curvature, pin cushion distortion and lateral colour than the entry level unit. On axis, no chromatic aberration could be seen at the edges of a nearby telephone pole as seen against a bright, overcast sky, while the control did show a little bit. And while the image looked good in many daylight scenes, it wasn’t long before I discovered that the binocular was not showing the contrast I had been enjoying with my wife’s Opticron Aspheric LE 8 x 25mm pocket binoculars. Looking into brightly backlit scenes revealed a potential problem with the Pirsch; there was some flaring and internal reflections coming through. So that caused me to investigate the matter further.
A cursory examination of the binocular review literature revealed something rather shocking to me. Very few reviewers had the presence of mind to investigate and report back on light leakage within the binocular, which can lead to very incomplete knowledge on how an instrument ought to behave under real-life situations. I consider it essential information for any savvy buyer, as it doesn’t matter how well a binocular is appointed with high-tech features if they can’t manage to adequately suppress stray light in the optical train. To me, this is Optics 101.
Fortunately, this is easily done by carrying out an indoor test using an iphone with its torch turned up to its maximum brightness and examining the in-focus images of how that light is delivered to the eye whilst looking though the binocular in a darkened room a few metres in the distance. You can also glean good information on how well a binocular will deliver by pointing the instrument at a bright street light or the full Moon(this is a considerably less severe test but an important one in any binocular assessment).
Well, the tests were very convicting. Not only was there many bright internal reflections but the Pirsch binocular seemed to be causing bright light sources to become diffused across the field of view, manifesting as a contrast-robbing, circular haze. And it was the same when I pointed the binocular at a bright sodium street light. I had not seen such terrible control of stray light since the day I tested a very inexpensive Celestron Nature DX 8×25 unit several months back. Needless to say, I was not a happy bunny! Incidentally, even my entry-level control optic showed far less flaring and internal reflections than this purportedly “premium” instrument!
As another control for these tests, I employed my most excellent Barr & Stroud Savannah 8 x 42, which shows remarkably little flare and diffusion of light under the same conditions. Indeed, as I already communicated in a previous blog, this superb instrument possesses the same level of glare and internal reflection control as a Swarovski EL Range 10 x 42 unit I recently subjected to the same tests. The reader will note however, that no roof prism binocular, no matter how well built it is, can completely eliminate such optical side effects.
A curious aside: I wonder will flare and internal reflection testing suddenly enjoy an upsurge on future binocular forums? Hmmm.
I suspect that many of these pocket binoculars are not tested for flaring and/or internal reflections because these small instruments are not recommended for night time use and so any problems they have in this regard might easily slip below the radar. I would check out your instrument to see how it fares in this regard.
For me, a binocular, no matter how small it is, should pass these tests. Remember, we’re not looking for perfection here. If you’re viewing a city scape at night or gazing at the Moon from time to time, your pocket binocular should have minimum light leak and scatter, so that it does not show up in ordinary use. Is that really too much to ask for?
I don’t think so!
Verdict: The Bresser Pirsch 8 x 26 possesses excellent mechanical features but its optics do not match its mechanics. Not recommended. Luckily I had registered the instrument with Bresser to enable the terms of the guarantee to be fulfilled.
So how did the Kowa SV 8 x 25 fare in comparison?
Here is what the company promised.
Well, the package I received came in a small box, containing the binoculars, instruction manual, carry strap and eyepiece caps but no objective covering caps. Unlike the Pirsch, the Kowa is double hinged, which enables you to fold the barrels under the bridge,. making it truly pocketable. You can get an idea of the transportable size difference of both the Pirsch and the Kowa by comparing the size of their carry cases;
My first impressions of the Kowa SV 8x 25mm binocular were favourable. It is small and rather cute looking. Kowa engineers deliberately designed the instrument to be very lightweight using modern materials. It has a very well armoured body with a tough, coarse- feeling rubberised exterior.
The eyecups twist up and down like the Pirsch but appeared to have only two fixed settings; fully extended or retracted. You can however, set the eycups at any position and they will hold their place.
The Kowa glass had what seemed to be immaculately applied anti-reflection coatings on the eye lenses and objectives, which almost disappear when examined head on. Kowa also apply a hydrophobic coating on the elements that allegedly repels water, oil etc, making cleaning the exterior optics that little bit easier.
And here is what the objectives look like under inspection. Kowa engineers applied extra armouring around the nicely recessed objectives for added protection.
The focuser is made of a soft material that effortlessly moves clockwise and anti-clockwise. I found that it was smooth and very responsive in use, with little in the way of stiction.
Like the Pirsch, the instrument is fully waterproof and is nitrogen purged. The optics are fully multi-coated and a phase coating applied to the Schmidt-Pechan roof prisms. But at this stage in the game, I had learned not to place my hope in an instrument based solely on these claims. I recalled the story of the little Celestron Nature DX which also advertised such advanced optical treatments, but failed miserably in field use.
Like the Pirsch, the Kowa barrels were well collimated and the field of view was found to be slightly smaller than the Pirsch, at just over 6 degrees. But when I began to assess the optics of the unit, I hit my first snag. The smaller eye lenses on the instrument made it very difficult for me to accurately position my eyes and I immediately noticed that I was frequently experiencing black outs as I moved from one daylight target to another. It did have better eye relief than the Pirsch though, allowing those who wear eyeglasses to use it fairly easily.
Worse still, I noticed that when I was observing with the Kowa in bright daylight conditions outdoors, I could see a faint ghosting in the field which would only vanish when I pressed my eyes tightly against the eyecups. The contrast was noticeably better in the Kowa images though, with excellent control of colour and seidel aberrations. But I was worried about the ghosting I saw, and so decided to perform my iphone torch test to see what was what.
Such testing revealed some problems. While the horrible diffused light I saw in the Pirsch was far better controlled(but nonetheless present), the test revealed a pretty bad case of on-axis flaring. My heart sunk as I contemplated the implications of the test. This would also show up in nightime test I told myself, and I waited until the evening to find out for sure.
Turning the unit on a bright sodium lamp all too easily revealed a pretty bad dose of on-axis flaring which ruined the image. And though internal reflections were much better controlled in the Kowa than in the Pirsch, the flaring on bright nocturnal lights was, quite frankly, very annoying and downright unnaceptable. And yet again, my entry-level control binocular fared better than the prestigious Kowa in the same tests.
I really hoped Kowa, a company which enjoys a strong reputation for precision, high-end sport optics, would be able to deliver a binocular image without this degree of flaring, but alas, it was not to be.
Visibly upset, I contacted Kowa UK to report the result. They quickly responded and apologised to me for the fault, explaining that this was a very ” unusual” finding.
Well maybe. But it didn’t stop me immediately packing up the instrument and its accessories and returning it to amazon. I received a full refund, but had no interest in testing out a replacement unit. Once bitten twice shy.
Note added in proof: Control of light leakages bares little correlation to the price paid for these binoculars. For instance, my Barr & Stroud 8 x 42 and 10 x 50 roofs have a retail value of about £130 and £80, respectively, but have excellent control of stray light. If these did so well, why couldn’t the little pocket binoculars deliver?
Ich verstehe nicht.
What about the Olympus 10 x 25 WPII? I took a chance on this product also. Retailing for about £70, it offered all the same features as the Kowa binocular. Indeed it was almost a carbon copy of the Kowa, except for the magnification and focus wheel, but alas it also showed too much daylight glare when pointed at brightly backlit objects, so that went straight back to amazon as well. Though sharp in the middle of its relatively massive field(6.5 angular degrees), the Olympus binocular showed very distorted images in the outer 30 per cent of the same portal. So, not great, either.
An Old Reliable: It’s not all doom and gloom though. Compared with the three binoculars I had evaluated thus far in this blog, my wife’s Opticron LE Aspheric 8 x 25 pocket binocular is in a completely different league optically. With minimum flare, no blackouts and good control of internal reflections, the little classically styled Opticron is very well built and just works, time after time after time.
Now a few years old, the Opticron LE Aspheric features multi-coated optics and silver- coated phase corrected prisms. Aspherical ocular lenses produce a very flat field that renders undistorted images right to the edge of the field. And though its field of view is a little restricted at 5.2 angular degrees, it’s a nice tidy portal with very well defined field stops.
The eyecups have just two positions; up or down. With 21mm eye relief, the instrument is extremely comfortable to view through. The double-hinge design does allow the barrels to fold up to pocket size though;
It has its own built in lanyard so there is no need to fiddle about attaching a neckstrap. The original Opticron Aspheric LE (with the green logo) is a bit on the urbane side though; it is not weatherproof and the outer armouring is smooth and non-texturised. But a few years back, Opticron gave this pocket binocular a bit of a makeover; the new Aspheric LE is waterproof and purged with dry nitrogen, making it that little bit more versatile than the first generation model. Eye relief is reduced to 16mm, which should still be plenty good for all users. It also has new eyecups and a re-designed focuser. Details can be found here.
The instrument is more expensive than the Pirsch and Kowa models though; ~£120. But that extra cost does buy you peace of mind, or so I’m led to believe.
I”m going to order up the new model to determine how consistent the quality is. I will report back in a wee while to tell you how I get on with it.
Watch this space!
September 10 2019: Well the new Opticron pocket binocular arrived safely today. So, what was in the goodie box?
The binocular was purchased from Tring Astronomy Centre, and I elected to have it shipped to me via expedited 24 hour delivery. The cost, including postage, came in at £120. Like everything else I have received from Tring in the past, the product arrived in perfect nick. It was double boxed, witth the package including the pocket binocular, an instruction manual, lens cleaning cloth, and warranty card, and a stylish padded carry case with the Opticron logo on the front. I even received a £75 wine voucher!
Unlike the original model, the make and specifications on the new model are embossed on the upper bridge. The armouring is also slightly more texturised than the sleeky, first generation model.
The original model had plastic eyecups, but the newer incarnation has what appears to be a slightly more comfortable rubberised overcoat.
I rather like the simplicity of the eyecups on this instrument. There are only two positions: fully extended or fully retracted. The 16mm eye relief is plenty good enough for eyeglass wearers(verified by my own tests).
The focus wheel is larger and a little easier to work with than the original model.That will make it easier to use with gloves on. I did find it to be a wee bit on the stiff side though, but I figure with more use, it will became easier to negotiate.
The ocular lenses are the same on both models; good and large and easy to engage with.
The neoprene carry case is very nicely made and fits the pocket binocular perfectly:
You can probably guess by now what I did first: yep, I performed my torch test to see how well stray light was being controlled inside the barrels. Well, it passed with flying colours; not perfect, but perfectly acceptable! Indeed, it was very similar to the results I obtained for the original model. Later, I performed a test on some sodium street lights and the results were very good. Only very slight ghosting and no annoying glare.
What a relief!
Conducting some observations during the day also delivered very pleasing results.The images are very bright, sharp and colour-pure, thanks to good quality glass, anti-reflection coatings and a silver mirror coating on the prisms. Like the original model, backlit scenes show excellent control of glare and certainly enough to satisfy the vast majority of users. The aspheric ocular lenses did a great job maintaining a very flat field nearly all the way to the field stop. Close focus was astonishing! I measured it at just 51 inches (~1.3m), so significantly less than the advertised 2 metres. A nice bonus!
Clearly the quality control on these instruments appears to be very good indeed.
Weighing in at just 291 grams, and with its double hinge design, folding it up and storing it in your pocket is a breeze. It’s nice to have a pocket binocular that does exactly what it says on the tin.
Alas, I was unable to perform my last test on the bright Moon owing to the presence of a weather system (the remnants of hurricane Dorian) passing over Scotland, but the results on stray ligt control gives me no cause to be concerned. It will pass the full Moon test with flying colours!
A Curious Aside: Here’s a binocular review posted on September 11 2019.
The reviewer even conducted tests for glare and flaring etc!
Don’t take my word for it; look at some other reviews of the Opticron Aspheric LE pocket binoculars to better establish a consensus:
Conclusions and Lessons Learned:
It is clear that good optical performance cannot be gleaned from checking the specifications of a pocket binocular. Claims of a product offering fully multicoated optics and phase corrected prisms etc count for nothing if they cannot suppress glare and internal reflections to an acceptable degree. In this blog I have sampled but a few models that fell short of my expectations. In the end, only the Opticron Aspheric LE 8 x 25 delivered the readies.
The best way to proceed with acquiring a pocket binocular is to test it out in person, if at all possible, before handing over your hard-earned cash. The reader should also be leary of any binocular review that does not mention or test for glare, flare and internal reflection. This is an essential feature that must be controlled if you are to derive the best performance out of your pocket optics.
Life’s too short to look through bad glass!
Opticron also manufacture a series of more expensive pocket binoculars in their BGAT PC Oasis series. These will also be a good bet, but you’ll have to cough up another £100 to acquire one. I may test one of these models out in the future.
I did consider a few ED models in my quest. For example, the Hawke Endurance ED 8x 25 has a wider field of view and retails for 20 per cent less than the Opticron(which has no ED glass), but is it as well built? And how do the optics fare? To be honest, I don’t know, as there wasn’t any discriminating reviews available for me to make a decision, but they might be worth a punt. I did contact Hawke asking them how well they suppress glare in their small pocket binocular and received a very quick reply. Here is a copy of my correspondence with the company:
I am writing to inquire about glare suppression and internal reflections in your Hawke Endurance 8x and 10x 25mm pocket binoculars.
I have been testing a few brands and some show very annoying flare and/or ghosting when pointed at a bright street lamp or a bright Moon.
Will your products pass such tests?
I appreciate that no binocular can completely eliminate these but all I am asking for is no obvious ghosting when pointed at the moon or strongly backlit scenes in daylight.
Thanks in advance of your reply.
|from:||Hawke UK firstname.lastname@example.org|
Thanks for your email and interest in Hawke Optics. The internal components of our binoculars are treated to be as glare resistant as possible. We use a combination of matte finishes and ribbed surfaces to prevent a flat reflective surface. However, it will never be possible to completely eliminate reflections like you are talking about and so even with these countermeasures, our binoculars will show some white out when looking towards a bright light source.
I wonder if any of you have tested the Hawke model? If so, I’d be very keen to hear from you. Failing that, I might just go ahead and purchase one to do a full review; warts and all.
I would also trust the optics in the Pentax AD bocket binocular, which also retails for about £100. But that’s not based on direct experience with this model, only an inference made from using two other binoculars from their line.
For a few hundred pounds more you can acquire excellent pocket binoculars from the ultra-premium end of the market from Zeiss, Leica and Swarovski. However, I don’t think you’ll notice any big optical differences between the Opticron and these though. The value lies more in their mechanics than anything else.
For me, I feel the Opticron delivers everything I could wish for in a pocket binocular; both mechanically and optically. It’s a quality product that will stand the test of time if looked after properly.
Well, I hope you found this blog to be informative.
Good luck with your quest to find a good pocket binocular!
Neil English’s newest title, The ShortTube 80: A User’s Guide, hits the bookshelves in early November 2019.
Post Scriptum: Shortly after local midnight on September 12 2019, I ventured outside to see if I could gain a glimpse of the bright and nearly full Moon, that had just past the meridian and about 17 degrees above the southerly horizon. I compared the Bresser Pirsch 8 x 26 to the Opticron Aspheric LE WP 8x 25. A brisk westerly breeze was blowing, quickly shifting the clouds over and then away from the Moon. During one such clear spell I pointed both instruments at its silvery white face and studied the images.
Result: The Pirsch showed annoying glare and some obvious internal reflections in the field. The glare also brightened the backround sky around the Moon, reducing contrast. However, the Opticron unit showed no visible internal reflections and only slight flaring when the Moon was placed just outside the field. The backround sky around the Moon was much darker to boot, showing clearly superior image quality to the “premium” Pirsch.