Book Review: The Binocular Handbook: Function, Performance and Evaluation of Binoculars by Holger Merlitz.

A technical treatise on binocular optics.

Title: The Binocular Handbook: Function, Performance and Evaluation of Binoculars.

Foreword by Neil English, author of Choosing & Using Binoculars

Publisher: Springer Nature

Author: Holger Merlitz

ISBN: 978-3031444074

218 Pages

Price UK: £39.99(Hardback)

It was with a great sense of anticipation that I finally got my hard-back copy of Holger Merlitz’s new book, freshly and expertly translated into the English language. Anyone who has expressed even a cursory interest in binoculars will be familiar with Holger’s accumulated writings on his website(, where he has built up a formidable portfolio of work covering all aspects of binocular optics, reviews and theoretical speculations. His new book, The Binocular Handbook: Function: Performance and Evaluation of Binoculars, represents the culmination of many years of work.

Holger presents a full treatise on binocular optics in this book, covering everything from the design and execution of theoretical optics and their applications to building binoculars, a detailed overview of how the eye-brain interfaces with the binocular before launching into some fascinating chapters covering the testing and evaluation of binoculars during field use. In total, 9 chapters arranged in 3 distinct parts, walk the reader through pretty much everything you need to know about the fascinating world of binocular optics.

Instead of exhaustively covering the material, I would like to highlight just a few interesting topics covered in the book. I was most impressed with Holger’s use of an aeroplane’s ride from the North Pole round the world as a way of explaining why phase coatings are needed in roof prism binoculars. I also enjoyed his inclusion of discussions on unusual, cemented prism formats, such as the Uppendahl and the Perger (page 51-54) arrangements, the latter of which doesn’t require a phase correction coating and is used in the design of the third-generation Leica Geovid. Holger believes there are no binoculars containing Uppendahl prisms, but I have heard it on good authority that the little Leica Ultravid 8x and 10 x 25 may still be using such prisms. 

I found section 4.8 to be particularly amusing when Merlitz discusses sealing and gas purging. The use of the noble gas, argon, in particular, has been touted as being superior to molecular nitrogen owing to its greater molar mass. But as Holger astutely points out on page 97, the very low ambient concentration of argon in air(less than 1 per cent) would create a powerful concentration gradient causing the argon to diffuse out faster than if it were filled with nitrogen under the same circumstances. But it’s worse than that: a binocular filled with argon will cause nitrogen to diffuse inward and increase the pressure enough to eventually damage the seals! It neatly explains why all the big European binocular manufacturers have stuck with nitrogen purging.

Chapter 5 is written by Gerhard Eller, a fellow binocular enthusiast and engineering veteran, who describes the construction of a fascinating 12 x 62mm binocular using twin Leica Apo objectives and Porro II prisms serving up an impressive field of view of 113m@1000m.

The book has full colour illustrations.

The discussion on depth perception in chapter 7 and 8 proved to be fascinating entries, especially since I’ve cultivated a particularly strong fondness for compact Porro prism binoculars over their roof prism counterparts. Merlitz discusses the Japanese made RISO-1 7 x 40 instrument which were employed by the US navy during the Korean War. Indeed, he further informs us that specialised stereoscopic binoculars used in precision range finding measurements had enormous separations in their objective lenses of the order of several metres! That said, while the enhanced stereoscopic effects of Porro prism binoculars are greatly appreciated by yours truly, Holger also discusses some disadvantages of this design, such as inferior close focus performance and an optical illusion called the ‘cardboard effect,’ which was previously unknown to me.

The human eye takes centre stage in the final few chapters. With its 3-megapixel colour camera(cones) and 120 megapixel light detectors(rods), it can respond to changing ambient light levels and even alter the spectral response of the human eye. I’ve always wondered why, for example, many older glasses I’ve viewed through have a yellow tint. In discussing the differences between regular BaK4 and BK7 glass versus their HT equivalents, for example, companies like Zeiss have been able to increase the transmittance at blue wavelengths which helps in low light observations when the human eye becomes more responsive to shorter wavelengths (so called scotopic vision).

Sections 8.2 through 8.4 discuss the interesting topic of binocular efficiency and dim target detection as well as the factors – magnification, aperture, exit pupil and eye pupil size – that determine the outcomes in broad daylight, twilight and under darkness. Magnification alone determines efficiency in daylight, but the situation becomes far more complicated during twilight and full darkness, enabling binocular enthusiasts to experimentally determine the relative importance of these factors in target resolution and detection. Indeed, I’m currently busy comparing and contrasting my two main binoculars – the 8 x 30 and 10 x 35 Nikon EII – with their similar light transmission and exit pupil size – under twilight and true darkness based on Holger’s analysis, to determine if these predictions are validated.

Section 8.7 offers an excellent overview of atmospheric scattering and I really like how the author brings some basic physics such as Rayleigh scattering into the mix. Later in chapter 9, he discusses colour bias in binocular images, explaining why many binoculars having a so-called warm tone exhibit better contrast by (Rayleigh)scattering shorter wavelengths of visible light. On the contrary, he also explains why instruments delivering a cool colour tone are often better for low light work, when the eye becomes increasingly sensitive to shorter wavebands.

These are but a few invaluable nuggets of information presented in this book. The reader will note that much of this surmising is not just based in optical theory but derives from the rich storehouse of practical experience with many fine binoculars he has amassed over the decades. In short, The Binocular Handbook will prove invaluable to keen binocular enthusiasts eager to determine the best instruments to use in their arsenal, with the author gently encouraging active experimentation under real life conditions. Like most good books, it raises more interesting questions than it answers, but rest assured, there is enough content in this timely volume that will keep you thinking and looking for years to come.

Highly recommended!

De Fideli.

Product Review: Zeiss Terra ED 8 x 42.

The Zeiss Terra ED 8x 42 Package.

A Work Commenced November 9 2023


Product: Zeiss Terra ED 8 x 42

Country of Manufacture: China

Chassis material: Polyamide, reinforced fibreglass

Exit Pupil: 5.25mm

Field of View: 125m@1000m(7.13 angular degrees)

Eye Relief: 18mm

Light Transmission: 88%

Close Focus: 1.6m advertised, 1.8m measured.

Coatings: Zeiss multicoating, LotuTec hydrophobic coatings on outer lenses

ED Glass: Yes(Schott ED)

Waterproof: Yes

Nitrogen Purged: Yes

Weight: 725g advertised, 728g measured

Dimensions:14 x 12cm

Accessories: padded logoed neck strap, clamshell case with zip lock, microfibre cloth, instruction sheet, rain guard and objective covers

Warranty: 2 years

Price(UK): £449.00

It’s been almost a decade now since Zeiss introduced their line of entry-level binoculars encompassing the Terra ED series. A few years back, I did a thorough test drive of the small pocket model and was duly impressed with its optical and ergonomic quality, I even investigated whether the quality of the original Japanese-made models of the Zeiss Terra ED Pocket were the same as their newer Chinese manufactured counterparts, finding that there was no discernible differences in performance between them. In this review, I’ll be reporting on the full-size 8 x 42 Terra ED.

During my investigation of the pocket model, I was contacted by a Zeiss Rep, who helped clarify many details about the Terra pocket binoculars but also offered some general comments on the philosophy behind Zeiss breaking into the mid-tier binocular market. She told me that their goal in marketing the new Terra ED line was to achieve ‘’best in class performance.’ She also told me that in the early days they were having some problems getting their Chinese employees to apply the coatings on the lenses to the standards established by Zeiss but that was close to being resolved. Fast forward a few years and I now feel that I have a truly mature product with all the initial manufacturing bugs having been eliminated.

First Impressions

The Zeiss Terra ED 8 x 42 is a handsome & well-appointed binocular.

I ordered up the instrument from Amazon. The package arrived in fine condition. The box was brand-new with no signs of tampering. I chose the plain, black-coloured model. Inside I found a nice quality storage box with a pretty alpine picture inside the top cover to whet my appetite. The instrument was found inside a well-made Cordura case – a scaled up version of that accompanying the pocket models. This is a far cry from the soft pouch that accompanied earlier incarnations of the same instrument.

The full-size 8 x 42 Terra binocular comes with a nicely fitting Cordura clamshell case.

The box also contained an instruction sheet with warranty information, a high-quality Zeiss microfibre cloth, and a good, wide, Zeiss-logoed neoprene strap. The instrument was located inside the case with the rubber rain guard and objectives covers attached.

Bellyside up.

I was pleasantly surprised when I took the binocular out for initial inspection. Zeiss apparently gave the larger Terra models a makeover in 2017, using a thicker rubber substrate to armour the re-enforced fibreglass chassis. It’s much more grippy than that found on the pocket models, smooth on top and nicely textured on the sides of the barrels. Unlike a number of other reports I’ve read, there was no strong smell from the rubber either. The Zeiss blue logo sits pretty on the broad single bridge.

Tipping the scales at just over 700g, the instrument possesses a median weight among 8 x 42 roof models I’ve tested. The large central focus wheel is superbly tuned. It rotates extremely smoothly with no play in either direction. Just shy of one full revolution clockwise brings you from closest focus(1.8m measured) to infinity and beyond. This is a very fast focussing mechanism – ideal for birding, as I was to discover.

The right eye dioptre is sensibly located under the right ocular lens and is fairly stiff to turn – a good thing surely. I’m glad Zeiss didn’t go for one of those gimmicky plastic locking dioptres found on similarly priced $500 binoculars, which are likely to malfunction sooner rather than later. Indeed, I personally don’t consider locking dioptres to be that desirable.

The twist-up eye cups are comfortable and very well designed.

The eyecups are excellently designed. Covered in soft rubber, they are extremely comfortable to rest your eyes against.  Four locking positions are offered, quite enough for most users. Unlike the 10 x 42 model, the eye relief is plenteous enough to image the entire field easily with ordinary glasses.

The objective lenses are nicely recessed. They have immaculately applied antireflection coatings that make the lenses almost disappear when viewed head-on. The large ocular lenses make centring one’s eyes easy and intuitive too. Zeiss had the presence of mind to include their proprietary LotuTec hydrophobic coatings to the outer lenses to cause water to bead and run off the lenses during downpours. You needn’t worry about the lenses fogging up in cold weather either. The same coatings will disperse any condensation very rapidly as my own testing verified.

The nicely recessed lenses have a beautiful magenta bloom.

I like the quality of both the rain guard and objective covers. Made from high quality rubber they fit snugly onto the instrument and provide excellent protection from the elements. The neck strap is of high quality – a good step up from the cheap generic designs you get with other models in the same price class.

Check out those large ocular lenses.

In the hand, the instrument feels great. It’s grippy, robust and with a silky-smooth focus wheel, it’s very easy to engage with. Overall, the Zeiss is a very handsome binocular both to look at and to hold and seems to be robust enough to withstand anything nature is likely to throw at it. This is one place where I disagree with the reviewer in Preamble 2 above. Good job Zeiss!


Inspecting the interior of the binocular when trained on a bright torch light revealed excellent results. There were no internal reflections or diffused light around the light source, but I did detect a weak diffraction spike – a common artefact in roof prism binoculars in all price classes. This was much more subdued than in the 8x 25 pocket Terras I tested though. The spike is not intrusive on larger light sources but when I trained it on small light sources in the distance, I could see that little diffraction spike. Overall though these tests proved quite excellent and so will make a great instrument for studying cityscapes or surveillance at night.

Examining the exit pupils showed very good results too(see below). They are big, round and have very good darkening around the pupils indicating good blackening of the interior and effective baffling.

A very good result.

I was very pleasantly surprised when I looked through this binocular. The view is excellent; bright, very sharp, wonderful contrast but what impressed me above all was its exceptional glare control. Testing the instrument in all sorts of conditions from bright autumn sunshine, dull overcast, and wet drizzly conditions yielded uniformly excellent results. Many other binoculars in this $500 price class have ED glass, but this binocular taught me that not all ED glass is created equal. This Zeiss contains Schott ED glass and it really shows! Other instruments I’ve tested in this price class tend to show glare in low light conditions or when pointed toward a strongly backlit target, but this nifty little Terra stubbornly refused to show anything significant. This is one of the optical virtues that sends it right to the top of the pack in this price class in my opinion. This also explains the excellent contrast of the images garnered by this instrument. While I could detect a very slight yellow tinge against a whitewashed wall, it made the images warm, enhancing the beautiful colour of autumn leaves. Many lesser binoculars are ruined by glare and even though they serve up perfectly sharp images, their lesser contrast brings them down a notch or two in perceived sharpness.

How does your binocular handle strongly backlit scenes like this? The Zeiss Terra ED handles it superbly!

Colour correction is excellent in this unit also. I could see none on axis and only a trace near the field stops even after testing it in very severe lighting conditions. The sweet spot is generously large. To my eye about 80 per cent of the field is very sharp with the last 20 per cent or so showing some softness. Pincushion distortion is very low and only manifests itself in the outer 20 per cent of the field. These low distortion images will be useful for studying architectural features.

Collimation was judged to be spot on as evidenced by how the binocular behaved under the stars. I also confirmed that the sweet spot extends to about 80 per cent of the distance to the field stops, with some field curvature and astigmatism morphing the stars significantly in the outer 20 per cent of the field. I also witnessed moderate illumination drop off when the Moon was moved from the centre of the field to the edges.

In summary, I was frequently reminded why Zeiss put their prestigious name behind this binocular. It has very high image quality and way above average resistance to glare of all types. I’m certain that it will delight the vast majority of people who look through it and therefore I’m in full agreement with the opinions garnered in Preamble 1 above. A thoroughly delightful visual experience!

Notes from the Field

The Zeiss Terra works flawlessly in wet weather.

The Zeiss Terra ED binocular is designed to operate flawlessly over a temperature range of -15 to +60C. In one test I left the instrument exposed to sub zero night temperatures for two hours(-3C), together with my Nikon EII 10 x 35. I can report that the focus wheel moved very easily and smoothly after this two hour exposure. In contrast, the Nikon focus wheel was much more sluggish and hard to turn until the grease had softened after warming up for a few minutes of it being brought back indoors.

Some of the more animated reviews I’ve seen, seem to be confusing a thin focal plane with depth of focus. Indeed, they seem to think that different binoculars offering the same magnification can show significant variations in focus depth but this is simply not the case. The main factor that determines focus depth is magnification – the lower the better. The super fast focus means that the focal plane is much thinner than found in a slower focuser taking say two or more revolutions to get from one end of its focus travel to the other. He also mentions the flat field of the Terra but I’m sure that’s just par for the course for a roof prism binocular. In another video, he compared a 10 x 42 Terra to a 10 x 42 Conquest HD and noted the Terra’s better colour correction.

The all but absent glare in the Zeiss Terra ED 8 x 42 makes it a particularly excellent instrument to use in dull overcast or low light conditions where colours become especially vivid. Browns and reds really pop in this glass! It was head and shoulders above and beyond my control 8 x 42s in this capacity. Views of the Moon are great: tack sharp, no glare or internal reflections and very little secondary spectrum within its sweet spot. Only at the edges of the field, did the Terra show some lateral colour but all within very acceptable levels. Is there anything I didn’t like about it? Well, yes; a small matter really. When I turned the instrument on a bright star field after dark, I noted how the brighter stars showed tiny diffraction spikes compared with my Porro prism binoculars, which produced perfectly round stellar seeing disks in comparison.  However, since I generally don’t star gaze with 8 x 42 roofs, this wasn’t an issue for me. The field of view of 7.1 degrees is also a little restricting, especially if you’re accustomed to enjoying expansive 7.5 or 8 degree fields. That said, I never felt ‘ tunnelled in’ while using it.

If you’re used to a slower focuser, the super fact focus wheel on the Terra 8 x 42 might take a bit of getting used to. But once you spend a few days in the field with the instrument, it becomes very easy and intuitive to use. Just a quarter turn brings targets from just a few metres away to several tens of metres away into perfect focus. This makes it particularly suited to high-intensity birding, and in this capacity, I enjoyed many moments following migrating Fieldfares and Redwings flit from the ground to the safety of trees in large groups. Sharpness at distance is also very noteworthy in the Zeiss Terra 8 x 42. I was able to pick off a tiny Goldfinch flying at a distance of 80 yards or so against a grey, overcast sky.

Conclusions & Recommendations

A gift from Zeiss.

The Zeiss Terra ED 8 x 42 was a very pleasant surprise. It has an extremely well thought-through design and seems very robust and reliable. Optically, I rate it quite highly. The images it serves up are tack sharp with well above average colour correction, contrast and glare suppression. Has Zeiss succeeded in achieving ‘best in class’ status with the Terra line? From the tests I’ve carried out the answer appears to be a clear ‘yes.’ You’re not just getting a mid-tier binocular here, it’s a Zeiss binocular and you can tell that from the moment you bring it to your eyes.

Highly recommended!

My new book, Choosing & Using Binoculars: A Guide for Stargazers, Birders and Outdoor Enthusiasts hits the bookshelves in December and is also available for pre-order.

De Fideli.

Product Review: The SvBony SA204 10 x 50 Binocular.

The SvBony SA204 10 x 50 package.

A Work Commenced September 17 2023

Product: SvBony SA204 10 x 50

Country of Manufacture: China

Exit Pupil: 5mm

Field of View: 114m@1000m(6.5 angular degrees)

Eye Relief: 19mm

Closest Focus Distance: 6m advertised, 5m measured

Chassis Construction: Rubber-armoured aluminium

Prisms & Coatings: BaK4 prisms, fully multi-coated

ED Glass: No

Waterproof: Yes, IPX6 rating

Nitrogen Purged: Yes

Dioptric Compensation: +/-4

IPD Range: 53-74mm

Tripod Mountable: Yes

Dimensions: 17.5 x 19.8 x6.4cm

Weight: 925g advertised, 875g measured

Accessories: Padded neck strap, rubber rain guard and objective covers, instruction manual, soft padded case

Price: US $84.99

Ever since its founding in 2009, Svbony has been delighting the astronomy and sports optics community with an expanding range of high-quality products offered at very affordable prices. SVBONY is an acronym which stands for Saturn(S), Venus(V), Birding(B), Optics(O), Nature(N), Youth(Y). I was first introduced to the company a few short years ago when I stumbled on their excellent SV202 ED roof prism binoculars, which have since gone from strength to strength and are now being enjoyed by an army of nature enthusiasts the world over. Not long before this time, consumers were left with very little option to shell out significantly more money for products that often left a lot to be desired quality-wise. Be sure to check out the most recent reviews of these binoculars. Since discovering the SV202s, I have also enjoyed some of their excellent spotting scopes, and regularly use some of their high-quality zoom eyepieces, like the SV191, which I’ve begun to employ extensively this season to observe Jupiter.

The impressive SV 191 7.2-21.6mm zoom eyepiece.

As a dedicated fan of Porro prism binoculars, I’ve steadily come to realise their exceptional value for money owing to great advances in technology, as well as their much simpler design compared with high-performance roof prism binoculars. Truth be told, it takes a lot of knowledge and technology to create roof prism binoculars that can even begin to approach the quality of a traditional, well-made Porro prism design. What’s more, many of the conventional objections purists have laid against the humble Porro prism binocular have now been satisfactorily addressed, including advances in anti-refection coating technology, water- and fog-proofing, and the introduction of modern twist-up eyecups with much better eye relief to accommodate eye glass wearers. In addition, advances in material science also means that good Porro prism binoculars can now be manufactured with lower mass chassis, allowing them to be carried longer in the field.

It was these considerations, as well as my own experiences with several budget-priced Porro prism models that led me to appraise one of Svbony’s newest products, the SA204 10 x 50, a traditional Porro prism binocular. Having ordered several products directly from their online store, I decided to purchase this instrument directly from Svbony too, since they’re currently not available from Amazon UK.

First Impressions  

The Svbony SA204 10 x 50 binocular.

The SA204 10 x 50 package took about two weeks to arrive from the Far East to my home. As usual with Svbony, I was extremely impressed with the attention to detail in how it was packaged during its long trip to the UK. The instrument arrived double boxed inside some bubble wrap to ensure that nothing moved out of place during transit.  All the accessories were also neatly packed away, including the ocular and objective covers, a carrying strap, lens cleaning cloth, a well-written instruction manual and a decent soft padded carry case. Inspecting the binocular, my first impressions were very favourable. The instrument is covered in a high-quality textured rubber substrate, ribbed at the sides for extra grip. The twist-up eyecups moved smoothly and were easy to adjust, keeping their individual positions firmly when clicked into place. Two intermediate positions are available between fully retracted and fully extended, so plenty of options for those who like to experiment.

Belly side up.

The aluminium central hinge is nicely tensioned, allowing you to easily adjust it to your preferred IPD. Once there, it stays rigidly in place. The rubber-covered central focus wheel has deep ridges to afford extra grip. Turning is very smooth with no free play. It ‘s quite stiff though, a consequence I suppose of the instrument being properly sealed and nitrogen purged. The focuser moves the eyepiece assembly up and down with no annoying wobbles I’ve seen in other instruments in this price class. 0.8 turns anticlockwise takes you from closest focus to jut beyond infinity. Eye relief is very generous. I was easily able to engage with the entire field using my varifocals, although I don’t wear spectacles when glassing under normal circumstances.

The dioptre adjustment is made using a small lever under the right eyepiece that rotates either clockwise or counter-clockwise, and I was easily able to find my optimal position. Once set in place, it stays there. I would say it’s very nicely engineered.

The large ocular lenses and twist-up eyepieces are easy to engage with.

The large ocular lenses have nice green multi-coatings and the objectives are decently recessed as all good binoculars ought to be. The objective coatings appear to be significantly more subdued to those applied to the ocular eyepieces and I detected a faint reflection off one of the interior lenses possibly indicative of one surface being singly coated. The rain guard and tethered ocular covers are quite basic but do an adequate job protecting the lenes from rain and dust.

The 50mm objectives have good coatings although there appears to be one surface that may be singly coated based on its appearance in daylight.

The instrument feels really nice in the hand with plenty of wiggle room to engage with my medium-sized mitts, making it easy to hold the instrument firmly. I was pleasantly surprised by the weight of the instrument without the strap and lens covers. Although the specs claim 925g, my SA204 tipped the scales at just 875g or 50 g less than advertised!  All in all, I came away with the impression that this was indeed a nicely appointed binocular, significantly better built than other 10 x 50 Porros I’ve tested in the past, including the Opticron Adventuer T WP and the Nikon Aculon.


My optical testing began by measuring the effective aperture of the instrument by directing my iPhone 11 torch into one of the eyepieces and measuring the size of the resulting circular shaft of light emerging on the other side of the objectives. By tracing a circle of diameter 50mm, I was able to show that the circular light shaft fitted snugly into the circle indicating that the SA204 was operating at its full aperture.

The SA204 10 x 50 operates at its full aperture.

In the next test, I examined how well the binocular handled a beam of bright light. Turning on a sodium street lamp after dark, I was relieved to see that only a few minor internal reflections were seen that were largely non-injurious to the image. There was no diffused light around the light ether. Consulting my notebooks, I reported a little more internal reflections for both the Nikon Aculon and Action EX Porros(both of which retailing for considerably more than the SA204) I reviewed some time back and about the same as I recorded with two models of Opticron Adventurer T, but not quite as good as that seen in the significantly more expensive Opticron Imagic TGA WP(a £200 value).

Looking at the exit pupils yielded quite good results. I recorded nice round circles but I could see some light leaks around the pupils suggesting that better blackening on the inside of the tubes wouldn’t have gone astray.

Left pupil.
Right pupil.

I had the opportunity to test the SA204 in all kinds of lighting conditions. The image is quite good: sharp, nice contrast, with a surprisingly large sweet spot. Colour fringing is very well controlled, especially off-axis.In this capacity, it’s certainly in a completely different league to the Nikon Aculons I tested, which displayed alarming levels of lateral colour to my eyes. Glare suppression is quite good too. I discovered that by retracting the eyecups one notch down from fully extended improved both the visibility of the field stops and the amount of glare I recorded. The instrument has an impressively wide field of view of 6.5 degrees with very well-defined field stops. I did perceive some peripheral softness near the field edges but it was not at all objectionable to my eyes. The instrument does display strong pincushion distortion however. I took the liberty of photographing some pink flowers at a distance of about 30 yards to give the reader an idea of how well corrected the field is:

Flowers imaged obliquely at 30 yards distance. Medium Resolution Image.

Close focus was measured at about 5m, less than the 6m advertised, putting it in the same ball park as a few other 10 x 50 Porro’s I’ve used. Of course, an instrument like this excels under the stars, where the 10x magnification and 50mm objectives pull in a lot of starlight. I checked collimation under the stars by defocusing the bright star Capella using the right eye dioptre while keeping the left barrel image as sharp as possible. The focused star remained well inside the defocused anulus not only in the centre of the field but also when placed to the extreme north, south, west and east edges, indicating very accurate alignment of the left and right barrels. Examining the Alpha Persei Cluster high up in the eastern sky reveals a rich cache of stars scattered across the field, I was delighted to see that they remained acceptably small and sharp across most of the field with only the outer 20 per cent of showing some mild distortion.  But even at the field stops bright stars like Vega and Altair remained quite tightly focused. Moving bright stars to the edge of the field showed little in the way of illumination drop off either. These results were most impressive for a large binocular retailing for significantly less than $100. Indeed, this instrument can be used to very good effect for general stargazing.

I estimated the field size by trying to image Alkaid and Mizar in the Plough, which have an angular separation of precisely 6 degrees 40’ or 6.66 angular degrees. I was unable to keep both stars in the same field of view but only just so, indicating that the advertised field size of 6.5 degrees was quite accurate. Views of the bright waning Moon rising over the eastern hills showed very nice results, with excellent crater detail coming through across the southern Highlands. There were a few minor internal reflections seen around the silvery orb, but they weren’t judged to be too offensive. I could detect a sliver of chromatic aberration at the edge of the Moon when centrally placed in the field  but this could be largely ameliorated by carefully reconfiguring eye placement. Off-axis colour fringing was more obvious though, but nothing I would describe as being out of the ordinary.

There was one negative however, and it manifested itself as I was imaging star fields in the vicinity of some streetlamps. Some of this peripheral light was entering the field, brightening the background sky by a tad. This disappeared however when I moved to the darkest location in my garden away from such light sources. In contrast, my Nikon E II 10 x 35(retailing at nearly ten times the price of the SA204) handled this stray light much more effectively. That said, I don’t count this as a major issue, and Svbony would do well to blacken the inside of the barrels that little bit more effectively.

Aperture Wins!

Comparing the Svbony Sa204 10 x 50(left) and Nikon E II 10 x 35(right) under the starry heaven.

Lest anyone be uncertain about the benefits of aperture, I took the opportunity to test both the SA204 10 x 50 and Nikon E II 10 x 35 under a dark country sky with no Moon during the wee small hours of September 17. Turning the instruments on the faint galaxy duo M81 & M82 in Ursa Major, I did manage to see them in both instruments, but they were much easier to see in the 10 x 50. The same was true when I moved the instrument to the celebrated Double Cluster in Perseus, now passing near the zenith at about 2.00 am local time. The view was compelling in both instruments, but the clusters were considerably richer in the larger glass. Ditto for the wondrous Pleiades and Hyades in Taurus as well as tracking down the trio of Messier open clusters in Auriga still low in the east. Indeed, I was quite impressed by just how well the SA204 managed to image the Hyades, with its constituent stars filling most of the field. I noted how well defined fiery red Aldebaran presented itself when positioned at the south-eastern edge of the field! All this to show that ‘you cannae change the laws o’ physics captain’ no matter how sexy and optically pristine the smaller, more expensive glass may be.

Conclusions and Recommendations

Great bang for buck!

The Svbony SA204 10 x 50 represents excellent bang for buck. It serves up a well corrected, sharp, bright and high contrast image with good control of chromatic aberration. It will serve as a fine general-purpose binocular, where it excels at low light observations and astronomy. I would have been thoroughly delighted with an instrument like this were I starting out in binocular astronomy again. I would however recommend using a more substantial neck strap than the generic one supplied with a chunky instrument like this. Better attention to internal blackening to improve contrast when observing under bright night lighting would also go a long way to making it an even better performer. That said, if you’re after a cost-effective instrument that does many things well, I would certainly recommend this neat 10 x 50 Porro to all and sundry.

Dr Neil English’s new 650+ page book, Choosing and Using Binoculars: A Guide for Stargazers, Birders and Outdoor Enthusiasts, caters for all budgets and will soon be published in paperback. Now available for pre-order.  

De Fideli.

An Open Letter to Oberwerk Regarding the SE 8 x 32 ED.

The venerable Oberwerk SE 8 x 32 ED.


Regarding the Obserwerk SE 8 x 32 ED

SN: 232161

Sunday September 10 2023

Dear Mr. Busarow,

After reviewing and continuing to use the 8 x 32 SE for a further seven months, I am more impressed than ever with this instrument. I’m not at all surprised that it has garnered more than 10,000 views on Birdforum alone, and an even greater number of visits on my website.  As detailed in my original review, I showcased many terrific features of this instrument which I will summarise as follows:

  1. Exceptional blackening around the eyepieces with near perfect exit pupils
  2. Complete lack of any internal reflections or diffraction spikes when directed at a bright artificial light source
  3. Exceptional colour correction from the small 32mm objectives
  4. Exceptional glare suppression
  5. Sensibly perfect images within its very large sweet spot
  6. Excellent edge-of-field performance despite its lack of field flattening optics
  7. Superb handling in all weather conditions
  8. Exceptionally well protected objective lenses
A Reminder: left exit pupil of the Oberwerk SE 8 x 32 ED.

I’ve already commented that its sharpness and colour correction are superior to the highly rated Nikon E II 8 x 30, but its optical and ergonomic excellence has also been noted by a number of other experienced observers including the Irish birder, ‘Sancho,’ who compared it to his Zeiss TFL 8 x 32 and, based on subsequent field testing, now uses it as his ‘favourite all-round’ birding instrument.  I would like to remind you of his posts here:

My Oberwerk SE 8×32 arrived today. I haven’t had much chance to “test” it, and in any case a birding bino needs to be tested over a few weeks while actually birding. Also, I am non-technical, so anything I say is “amateur user” opinion only, applying only to my eyes. I agree wholeheartedly with everything Dipperdapper says in the excellent review. Total cost to my door (in Ireland) was 368 euro, inclusive of 68 euro customs charges, plus postage. Communication and tracking details from Kevin in Oberwerk was excellent. At first, I was dismayed when I lifted the box…it felt heavy. But when I removed the packaging, and held the binos in my hand, they didn’t actually feel that heavy because the ergos and balance are excellent. Not unlike my Nikon SE 10×42, but about 50g heavier. The Oberwerk certainly is a tough, tank-like bino, feels very solid and durable. I like the longer objective barrels because I can get two fingers around them, as with the SE 10×42, and I find this helps further with stability. The objectives are deeply recessed, another feature I like because I presume they are more protected from stray light or damage. The focus wheel is stiffer than I would like, but I reckon this is the price you pay for a waterproof porro, like the Habicht 8×30. Although it is a wide wheel (see OPs photos), I find it a little difficult to get my fingers to it, and prefer the position of the FW on the Nikon 10×42. (OTOH, the diopter adjuster is on the right ocular, where the Binocular God intended….easy to adjust, but also firm enough to stay put). In any case the focusser has no play and turns smoothly. Eyecups twist in and out and have four positions. The bino came with a strap for the case, plus two straps for the bino…a lighter “stretchy” neoprene one for comfort, or a tougher fabric-type one. Try as I might, I could induce no CA, even looking against bare tree branches against a bright, high-cloud Irish February sky. In this it was the equal of my Zeiss TFL 8×32, which is excellent. The FOV (8.2 degrees) is similar, and to be honest it was sharp across most of the field, to the extent that to find any softness at all, I almost have to stick my eyeball into the bino and search sideways! In other words, the field-flattener question is a non-issue. I tried to induce flare/glare, and couldn’t manage that either, even while looking as close to the lightly-clouded sun as was possible without endangering my eyesight. I have no idea how to “measure” light transmission, but it seems plenty bright, not quite as bright as my TFL 8×32 but that’s unsurprising. I’m going to stick my neck out a bit here and say that I think the sharpness/constrast/pop (I don’t know how to separate these “concepts”) might be a little ahead of the TFL. However, this may be just because of today’s conditions, or I may be suffering from “new-bino enthusiasm”….it needs a bit more study out in the field, in different lighting conditions. The warranty is two years, but it feels like a bino that will be used by my as yet non-existent grandchildren. An interesting feature is that in the plain black box (thank you Oberwerk, no expensive fancy boxes!), there is a card headed “Quality Checklist”, with Date, Sale, SN etc., and all the features ticked off (under the headings Appearance, Mechanical, Alignment/Collimation, Resolution) and initialled “KGB” (whom I presume is Kevin rather than the defunct Soviet body). I’ll take these out and about over the next few weeks, and play with them a bit more, but I think they are a pretty stunning binocular at any price, and for 368 euro delivered a no-brainer, unless you favour roofs and very light binos.

Source: Birdforum link post #17

Furthermore, Sancho followed up with this post some months later:

Hi just reporting back on the Oberwerk SE 8×32, after four months of use. You know how it is, you never “really” know until you’ve used binos in the field in various conditions. I have to say these have become my favourite “all-rounder, grab n’go” binoculars, and my closet contains original SEs and some big European badges. I thought early on there was a bit of “play” in the focus, but there isn’t, it just focusses at different speeds as you turn the dial (if that makes sense). It is the best bino I have at suppressing CA and stray light, and the image has the punch and contrast that reminds me of my old (sadly sold) Nikon EDG 8×42. I love the stereopsis (3D?) effect of porros, so that’s a plus for me. I’m sorry I don’t have the technical vocabulary for talking about optics; I just love these and am thinking of buying the Oberwerk SE 10×42 to complement them.

Source: Birdforum link post #117

Another experienced observer, ‘Paultricounty,’ also offered his opinion on the 8 x 32 SE:

“These are bright and sharp binoculars. I’m going to get in trouble here with some Nikon guys, but they are brighter and at least as sharp as the Nikon SE’s. They’re more neutral in color than the Nikons and has a much wider field of view. There is no field flattener like the Nikons , so they’re not sharp to the edge. It’s a very usable FOV with fall off starting at around 75% , but no mushy edges like the Kowa BDII 6.5 and 8x and some other MIC bins. Contrast is as good as the Nikon and I couldn’t see the slightest amount of CA, clearly superior to the Nikon in that area.”

Source: Birdforum link post #83

Swiss binocular enthusiast Pinac, had this to say about the same instrument on the Oberwerk website:

I ordered one online at Oberwerk in Dayton OH on a Thu midday, Oberwerk dispatched the same day, and I got the SE at my home in Switzerland after 3 business days – not bad (for Oberwerk customer service and UPS)! I had been forewarned by the various reviewers that the SE is quite big and heavy for a 8×32 – it is indeed, but build quality and finish are excellent, and ergonomics are superb, the bino fits snugly into my hands, a joy to use. The immediate impression is that for a 250 $ bino, the optics are really good.

My sample actually magnifies 8.2 x. The measured RFOV and AFOV values are a bit narrower than specified by Oberwerk, but still very nice.

Plenty of eye relief; spectacle wearers should be fine.

Nice extra travel of the focus wheel of ca. 5 dpt beyond the infinity position.

Given that the number of available good 8×30 / 8×32 porro binos is continually shrinking, this is a very welcome additon to the binoculars market, not only for porro enthusiasts.

Source: Oberwerk Website Review# 2

And yet another review from a gentleman named Noah Lawes, who compared it to his Leica BN 8 x 42:

I’m extremely impressed with the 8×32 SE. It provides a beautiful, sharp, sparkling view. It compares favorably with my Leica BN 8×42, and it’s even better in some ways, including CA control, ergonomics, and handheld stability (especially when using the “hat trick” resting the bill of a cap on the prism housings. I’m working on a longer review which I plan to post on one of the forums, but for now, suffice it to say that I think this is a great binocular in absolute terms, and it’s just amazing that you can get it for $250.

Source: Oberwerk Website Review#4

It was also very favourably reviewed by the experienced Italian binocular enthusiast, Piergiovanni Salimbeni, who stated that its performance was similar to roof prism models costing €1K. Be sure also to check out the extensive video footage he captured through the instrument on his accompanying YouTube presentation.

Having said all that, I must report one additional observation regarding the instrument’s field of view. It was after comparing it to the Oberwerk Sport ED 8 x 42 that I noted its smaller field of view in comparison. Indeed, I conducted a star drift measurement and found its field of view to be 7.48 angular degrees, which is actually the same as the Nikon SE 8 x 32. Curiously, this was also noted by CNer Rustler 46 in this link.

I fixed the problem I had with the wandering dioptre, simply by securing my preferred position with a drop of Loctite superglue – problem solved!

No more dioptre wandering!

Finally, I suggest a few improvements to the instrument:

  1. Reduce the overall weight of the chassis by housing the optics in a polycarbonate body. Better still, a magnesium alloy chassis would offer greater ruggedness and a reduced overall weight. These days, magnesium alloy is not confined to high-end models but is now being offered even on budget-priced instruments.
  2. The focus wheel could be tuned better. Some owners have complained that there is some slack in the focuser, while others have noted its overly stiff tension. Improving this important ergonomic feature will greatly improve its enjoyability.

Please don’t be discouraged concerning the undeserved attacks Oberwerk has endured regarding its Chinese manufacture. Is not China a sovereign nation, just like all the other nations under the sun? Does it not have people? I note that most of the negativity came from folk who never experienced the instrument first-hand. Indeed, I suspect from the sheer volume of views that many of these dissenters actually ended up secretly purchasing the instrument lol!

In summary, it’s no exaggeration that the Oberwerk SE 8 x 32 is destined to become one of the great 32mm binoculars of our time. It’s all the more remarkable that you were able to bring it to market at such an attractive price point, which resonates well with my key objective to provide the reader with genuine bargains in today’s market in order to grow this wonderful hobby worldwide.

I wish you continued success with this amazing product!


Neil English PhD.

Author of the new book, Choosing & Using Binoculars: A Guide for Stargazers, Birders & Outdoor Enthusiasts, which will soon be published by Springer Nature.

De Fideli.

Book Review: Britain’s Birds: An Identification Guide to the Birds of Great Britain & Ireland.

A Work Commenced September 1 2023

Title Britain’s Birds: An Identification Guide to the Birds of Great Britain and Ireland

Authors: Rob Hume, Robert Still, Andy Swash, Hugh Harrop & David Tipling

Publisher: Princeton University Press

ISBN: 978-0-691-19979-5

pp 576

Price(UK): £20.00

Though I certainly wouldn’t call myself old, I’m certainly old school, preferring traditional ways of doing things compared with modern ‘gee whizz’ techniques. And when it comes to birding, I enjoy the challenge of first seeing and studying a new species, taking some notes, and then doing some bookwork to make a formal identification. Up to now, I’ve been using the RSPB Handbook of British Birds, which has served me quite well. It’s packed full of details about bird behaviour, habitats and basic biological information, but the illustrations, while being decent, have sometimes lacked enough detail for me to nail the identification of many smaller birds, such as warblers and finches. But that’s where this new work, Britain’s Birds: An Identification guide to the birds of Great Britain and Ireland hits the mark. This new work is lavishly illustrated with excellent full-colour photographs – a total of 3,591 in all – of the birds of the British Isles in their various stages of life, which makes identifying species much easier. The subjects are presented in their natural habitats which can prove very important to making those final decisions on the identity of a target.

Unlike the RPSB Handbook, the accompanying text is very concise and, for me, achieves an excellent balance between providing enough information to achieve an identification but leaving out unnecessary extraneous details that can all too often side-track the reader. The field experience of this multi-author text is abundantly in evidence, with astute insights conveyed to craft succinct ‘word pictures’ that clearly reveal expert identification knowledge. Each bird species is accompanied by a map of the British Isles showing where they are most likely to be found, together with arrows conveying migratory routes from Scandinavia, central Europe and Russia, as well as where summer migrants to the British Isles depart these islands in the autumn.

A typical page.

Although Britain’s Birds is touted as a field guide, its substantial weight – a whopping 1.4 kilograms – precludes its regular use as a true resource that can be used in the great outdoors. But it has a good quality sewn binding unlike the glued pages of the RSPB Handbook, which will increase its longevity going forward.

I found one entry that genuinely confused me. On page 474, the entry under ‘Nuthatches’ shows a map of the British Isles where you would come away with the impression that this species is not actively present in Scotland. This seems to be an anomaly. Nearly every passing day I’ve recorded two and sometimes many more of these birds in many different locations throughout Scotland. Nuthatches are alive and well in Caledonia!

Although published by Princeton University Press, 40 pence out of each purchase is donated to the RSPB. Undoubtedly, the RSPB, which is now approaching the 130th anniversary of its founding, has done a great deal of good in raising awareness about bird conservation and initiated many schemes across the country to conserve endangered species, there are worrying concerns that this charity has recently been infected by woke ideology, recently launching a scathing invective against the British government. I for one do not want any charity or public institution becoming politicised and promoting climate change alarmism and other ridiculous scaremongering claptrap. I don’t want to see the RSPB go down the dangerous road of virtue signalling- a path that has ruined numerous other charities. If you go woke, prepare to go broke!

That being said, Britain’s Bird’s is a tremendous work that deserves great success. Now in its second(2020) edition, it’s an indispensable guide that birders and naturalists will find invaluable. And at a retail price of £20, it’s an absolute steal!

Highly recommended!

De Fideli.

Product Review: Oberwerk Sport ED 8 x 42.

The Oberwerk Sport ED 8 x 42 package.

A Work Commenced August 21 2023

Product: Oberwerk Sport ED 8 x 42

Country of Manufacture: China

Exit Pupil: 5.25mm

Chassis: Rubber Armoured Magnesium Alloy

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

Close Focus: 2m advertised, 2.36m measured

Eye Relief: 15mm(Useable)

IPD Range: 57-74mm

Coatings: Full Broadband Multicoated, Dielectric coatings on BaK4 prisms

ED Glass: Yes FK-61

Waterproof: Yes

Nitrogen Purged: Yes

Dimensions: L/W: 14/12.5cm

Weight: 671g advertised, 728g measured

Warranty: 2 years

Price: $329.95

In previous reviews I expressed my great admiration for the new Oberwerk SE Porro prism binoculars, which offer exceptional optical performance for their modest price tags. These experiences got me very intrigued about the company’s Sport ED roof prism binoculars, offered in the popular formats of 8 x 42 and 10 x 42. Could these deliver the ‘Wow Factor’ I had experienced while using the SE Porros?

Admittedly, this was going to be a tall order to pull off, especially in light of the many similarly priced models now available to the consumer offering many of the same features, at least on paper. Moreover, my love of high-quality Porro prism binoculars had somewhat dampened my enthusiasm for roof prism binoculars in general. But after putting the 8 x 42 Sport ED model through its paces in a variety of favourable and adverse lighting conditions, I think the answer is a confident Yes!

Ergonomic Features

An exceptionally handsome binocular.

I contacted Oberwerk owner, Kevin Busarow, who agreed to send me a unit for review. The instrument arrived well packed and double-boxed together with its standard accessories. My first impressions were certainly very favourable. While I’m not a fan of garish colours, I have to make an exception for this binocular. This is one handsome instrument, with its very fetching dark green rubber armouring and black, twist-up eyecups complemented by the cherry apple red anodized aluminium focus wheel and right eye dioptre ring.

The textured rubber armouring is exceptionally grippy without being overly thick, keeping its overall weight down. Even in wet weather, your fingers will not slip up. The focus wheel is truly excellent. The deeply knurled edges make it exceptionally easy to turn with one finger, rotating smoothly in both directions with zero free play. Indeed, this is probably the very best focus wheel I’ve personally encountered in a roof prism binocular! 1.75 turns anticlockwise takes you from closest focus to beyond infinity.

Ditto for the right eye dioptre ring. It’s very hard to rotate but you get there in the end. Once set it will stay in place!

Belly side up.

The rubber-clad metal eye cups have two intermediate positions between fully retracted and fully extended. Moreover, after clicking into place, they hold their positions very firmly indeed. And there’s plenty of eye relief for the bespectacled among us too. I was easily able to engage with the entire field while wearing ordinary eyeglasses.

The objective lenses are unusually well recessed(~12mm)  from the end of the barrels, helping to protect the coatings from the vagaries of the weather as well as acting as a protective barrier against stray light. The large(23mm) eye lenses make centring your eyes child’s play.

Note the very deeply recessed objective lenses.
Large eye lenses make for very easy centring of your pupils.

Being very compact at just 14.5cm long and 11cm wide, the Oberwerk Sport ED 8 x 42 feels great in my medium sized hands. My right-hand fingers comfortably fall on the bridge and can wrap around the right barrel, while my left index finger naturally rests on the large focus wheel rendering an exceptionally secure handling experience. All-in-all I would rate the ergonomic features of the Oberwerk Sport ED as superb; easily as good as anything I’ve seen from the top European manufacturers.   

Optical Assessment

I began my optical testing by looking for internal reflections and diffused light around an intensely bright light source. Setting my iPhone torch to its brightest output, and examining the image from across a room, I got an excellent result. I detected only a couple of very feeble reflections, no diffused light around the light source and no diffraction spikes. The same was true when I turned the binocular on a bright sodium streetlamp after dark.

Next, I photographed the images of the exit pupils. As you can see below, the results are very good; perfectly circular with plenty of darkness immediately around them. There is some light leakage set well away from the pupils but even with fully dilated eye pupils, you’re unlikely to be affected by it.

Left Pupil.
Right Pupil.

Now for the juicy bits. When I first set the Sport ED 8 x 42 to my eyes, I assumed the optimal position of the eye cups was in their fully extended position, as they usually are. But that yielded a slight tunnelling effect which prevented me from viewing the field stops clearly, but I quickly found my ideal setting by retracting the eyecups one notch down.

How are the views? In a word; excellent! But to elaborate, the Sport ED served up tack sharp images from centre to edge. Indeed, testing the binocular alongside my Svbony SV 202 8 x 42 ED ‘control’ I was able to resolve finer grain detail on the wooden beams on a climbing frame located about 80 metres in the distance. This instrument has a remarkably large sweet spot, and while the field of view is already generously large(8.1 degrees), it feels even more expansive by virtue of the sharp field edges. This is a remarkable result given that the instrument does not employ field flattening optics! Pin cushion distortion is also very well controlled in this instrument being noticeably milder than that observed in the Svbony control instrument. Colours are bright and true to life with a slightly warm tone which I very much enjoyed.  

Glare control is decent in the Oberwerk Sport ED 8 x 42. Only in the more severe lighting situations did I detect some. Colour correction is also WAY above average, even for its ‘ED’ billing. Indeed, after conducting many hours of testing on a variety of high-contrast targets, I could only detect the merest trace of off-axis chromatic aberration, and only at the extreme edges of the field of view. Those who find colour fringing annoying will find the Oberwerk Sport ED to be a refreshing break from the norm!

Notes from the Field

A wonderful companion in the great outdoors

One of the first tests I performed was to check collimation under the stars. This is easily done by turning the right eye dioptre so that it defocuses a bright star in the right barrel while the left barrel keeps the star tightly focused. The focused star stayed in the centre of the defocused anulus, not only in the centre of the field, but also when the star was moved around the field, checking as I did for possible detachment. The star remained centrally placed, irrespective of where the anulus was positioned inside the field. This confirmed that the instrument was very accurately collimated.

Excellent collimation also explains why I’ve been able to enjoy prolonged panning activities with this binocular, its soft eyecups being very comfortable to place your eyes against. The view is very immersive, almost as if you’re sitting in the image. Contrast and resolution are excellent, especially over longer distances. For example, I could easily pick off the variegated colours of a Goldfinch in flight over 150 metres away. The Sport ED 8x 42 has that crystal clear clarity reminiscent of high-end European binoculars like the Zeiss Conquest HD but with a significantly larger field of view.

Just a half a turn of the ultra-smooth focus wheel covers the vast majority of targets from about 8 metres out to infinity.  Closest focus was measured at 2.36m, a little longer than advertised but plenty close enough for viewing insects or other targets at proximity.

The excellent sharpness of the image was abundantly in evidence when I turned the Oberwerk Sport ED 8 x 42 on the stars. Aiming the binocular on the Alpha Persei star cluster, I immediately noticed the very fine pinpoints of starlight served up by the instrument. The stars making up this celebrated cluster were incredibly fine, with the subtle colour differences among its members easily discernible. The fineness of the stellar images were unquestionably better than any roof prism binocular I’ve tested in this price class.

My subjective impressions of a large sweet spot were also confirmed under the stars. In a sense, the eye can deceive during daylight hours. The ‘trickery’ of visual accommodation and all that….. Centring Altair and moving it across the field, I noted that the image of the star stayed tight and pinpointed most of the way to the field stop. To my eye, it only showed noticeably bloating in the outer 15 per cent of the field, where slight refocusing restored the image to a tight pinpoint of white light. Conventional wisdom has it that field flattening optics are necessary for observing pristine star fields right out to the edges but the very mild field curvature in the Sport ED show that excellent results can be achieved without such optics.

Conclusions & Recommendations


Test driving the Oberwerk Sport ED 8 x 42 has been nothing short of a revelation. Just when you thought you’ve seen it all, along comes an instrument like this that upsets the apple cart. Oberwerk has really hit the ground running with the Sport ED roof prism binoculars, as the many other reviews also attest. This is a seriously good piece of kit. For a very reasonable price you get an extremely well-made instrument that functions beautifully in field use. It has superb resolution, contrast, ergonomics, and engineering, and in my opinion, there’s nothing to touch it in this price class with a fit and finish more reminiscent of a £1k instrument. But that seems to be the siren call of Oberwerk in general. Not only has it made its name in high quality large aperture binoculars, the company’s new lines of compact binoculars are also making heads turn. And that’s great news for the consumer and the hobby in general.

Dr Neil English explores the fascinating world of binoculars in his up-and-coming book, Choosing and Using Binoculars: A Guide for Stargazers, Birders and Outdoor Enthusiasts due out in late 2023/early 2024.

De Fideli.

Lights in the Sky- Seeing Through The UFO Phenomenon.

At the end of June 2021, after months of hype all over the internet and a string of sensationalized reports by the main stream media, the Pentagon released a 9 page report1 on the subject of 144 Unidentified Flying Objects (UFOs)or Unidentified Aerial Phenomena(UAP) documented in recent years by the US government. Millions of people all over the world anxiously awaited the findings from that report but were ultimately left disappointed and frustrated because the same report was completely inconclusive and never even mentioned the word ” extra-terrestrial” or ” alien.” Instead, the report merely stated that,

“Most of the UAP reported probably do represent physical objects, given that a majority of UAP were registered across multiple sensors, to include radar, infrared, electro-optical, weapon seekers and visual observation1.

But the Pentagon report was presaged by further hype fuelled by Harvard Astronomer, Avi Loeb, who released a sensational book, Extra-terrestrial: The First Sign of Intelligent Life beyond Earth2, in February 2021, in which he claimed that an asteroid nicknamed Oumuamua, which passed through the outer solar system in a highly unusual orbit in late 2018, displayed signs of artificiality, both in terms of its of movements and physical properties. Since then, several natural explanations have been forwarded by scientists to explain the behaviour of Oumuamua, but predictably, those were largely ignored by the media. A few months earlier in December 2020, Haim Eshed, a retired army general and former head of Israel’s Defence Ministry’s space directorate, claimed in an interview that Earth has been contacted by a “galactic federation” of extraterrestrials,3 and that “they have been waiting until today for humanity to develop and reach a stage where we will understand, in general, what space and spaceships are.”

Then on July 26 2023, the US Air Force officer and former intelligence official David Grusch appeared before the House Committee on Oversight and Authority, giving testimony on the government’s alleged coverup of evidence of Unidentified Anomalous Phenomena (UAPs), relating to the congressional committee that the US government were in possession of physical alien spacecraft since the 1930s, with evidence that included not only large components of the spacecraft but “biologic material” as well.

Stories such as these form the basis of a multi-million-dollar industry in the form of books, documentaries, the internet and Hollywood Sci-Fi blockbusters, entertaining countless millions of curious individuals across the world. But why are some people captivated with UFOs and extra-terrestrials and on what basis do they believe in their existence? Furthermore, how should we, as Christians, respond to such events?

 Test everything; hold fast to what’s good4

That famous quote from St. Paul, writing to the Church in Thessalonica, provides a great place to start. The secular world has been fed a staple diet of evolutionary ‘science’ that powerfully affects the way many people think. The reasoning sounds both rational and straightforward, at first glance; life evolved on Earth and our planet is one of countless quadrillions scattered across the Universe. Life therefore must have taken hold on many worlds, and in many epochs, so it’s reasonable to expect that intelligent spacefaring aliens exist.  Unfortunately, though, the latest science is casting severe doubts on this worldview.

For one thing, there are now serious doubts that evolution, as described by biologists, really happened. The origin of life is a profound mystery and given the astonishing complexity of even the simplest living cells, there is effectively zero chance that it happened by accident5. Indeed, it is arguably true that understanding how the first living cells came into being represents the greatest scientific problem of all time. Added to this, the explosive origin of most of the advanced animal body plans in existence today which emerged within a geological ‘blink of an eye’ in an event called the Cambrian Explosion, has still not been explained to any degree of satisfaction by evolutionary biologists.  Furthermore, the fossil record, which scientists have now unearthed in great detail, doesn’t show any evolutionary progression over the 3.8 billion years or so since its inception. Instead, it reveals many extirpation events followed by equally rapid speciation episodes, in contrast to the expected gradualism of Darwinian evolution. Simply put, we can be reasonably confident that if a scientific theory approaches the truth, the uncertainties become smaller over time. The problem with the evolutionary paradigm is the opposite – the error bars are increasing… and rapidly.

Coupled to this is the growing realization that most of the planets orbiting other stars, both within our galaxy and in myriad other galaxies scattered across the cosmos, are now considered very unlikely to harbour habitable worlds. For example, as much as 80 or 90 per cent of all the stars that exist are cool red and brown dwarfs that would require their habitable planets to be located far too close to their surfaces to be warm enough to allow liquid water to exist. Yet the same stars are highly unstable, firing off dangerous high energy flares and ferocious stellar winds that would damage fragile living systems5. What’s more, when you factor in all the other requirements for a viable biosphere, Earth stands out like a proverbial sore thumb as being very special indeed!

We therefore suffer somewhat from what scientists call observational bias;  because we see our planet teeming over with life, we naturally assume the same thing happened on countless other worlds.  But, as the distinguished organic chemist, James Tour, quipped.

 “Life should not exist. This much we know from chemistry. In contrast to the ubiquity of life on Earth, the lifelessness of other planets makes far better chemical sense5.”

In addition to these problems, there are real issues trying to explain how physical beings could traverse the vast distances of interstellar space, as well as surviving the enormous forces they would encounter in manoeuvring in the spectacular ways they do in recorded video footage. Indeed, there is a real possibility that these recordings are part of some greater, overarching deception.

Biblical Guidance

If there is life out there, and intelligent life in particular, it must have been placed there by God. Yet the Biblical narrative gives us other clues about whether space-faring ETs exist or not.  The secular world view posits that humans emerged from other lifeforms accidently, but the Bible makes it clear that the Earth was first prepared before humankind was placed here. Living things made Earth habitable for humans and continue to provide a life-support system for human flourishing. Would God create worlds packed with life without placing sentient beings on them? That’s a good question, but I suspect not.

Similar conclusions are reached by the Christian astronomer and young earth creationist, Danny Faulkner(PhD Astronomy Indiana University), in his book, UFOs & ETs; a Biblical and Cultural Exploration of Aliens.6 Faulkner squarely lays the blame with the brainwashing of the general public in accepting evolutionary thought:

“We must realize that nearly all discussion about such matters has been within an evolutionary framework. That worldview assumes the plurality of worlds-that life has arisen on many other planets in the universe, and that life on at least some of those planets is intelligent. Hence, in the evolutionary worldview one might expect that extra-terrestrial aliens will visit Earth from time to time. However, Christians ought not to adopt an evolutionary worldview. Instead, we ought to base what we think about on the Bible, not the ideas of men. Evolution is clearly contrary to Scripture, and so life only exists where God created it. While the Bible does not explicitly state that God created life only on Earth, the clear implication from Scripture is that God made life only on Earth and that man is the centre of God’s attention. Therefore, within a Biblical worldview, one would reject the plurality of worlds idea and would not expect extra-terrestrial aliens to have visited Earth(or even to exist)6.”

Furthermore, we read in the passages of Scripture that Jesus died “once for all7.”  If there are other civilizations out there, did Jesus die for them too? Some theologians have suggested that these beings might have not fallen, as Adam and Eve did in the Garden of Eden, and so were in no need of a Saviour. But we read that the entire creation is groaning8 and that God has reserved this current Universe for a fiery destruction9. If those putative civilisations exit elsewhere in the Universe, they too will perish and that would make God a monster, which is clearly a theological non sequitur!

 Occult Connections

But there appears to be a more sinister façade to UFOs(or UAPs) and ETs. Many in-depth studies conducted over many decades have shown a strong connection between these phenomena and the occult, and which often involve narratives that serve to undermine Christianity in particular. In their now classic work, Lights in the Sky and Little Green Men: A Rational Christian Look at UFOs and Extraterrestrials9, astronomer Hugh Ross, theologian, Kenneth Samples, and political scientist, Mark Clark, showcase many studies linking the obsession of the New Age movement with extra-terrestrials and flying saucers. They conclude that, while most of these sightings can be discounted by natural phenomena, hoaxes or human-made technological devices, a small number of residual cases cannot be explained away and display properties that suggest that they are real but non-physical in nature, that is, these events are demonic in nature and represent deceptions by fallen angels who can move inter-dimensionally, at one moment looking real and the next, vanishing into thin air. In this capacity, The UFO phenomenon could well be part of an End Times deception.

To my mind, our culture’s fascination with spacefaring aliens merely represents a post-modern form of pagan idolatry, a convenient distraction from the things we ought to think about. Unwilling to accept the reality of an omniscient Creator, they resort to imagining beings far in advance of our own as new gods who will solve all of humanity’s problems. Yet, as I’ve explained earlier, this is little more than fanciful thinking that has no basis in scientific reality. In short, we simply don’t expect such agencies to exist! I suspect that, in the end, the only aliens we’ll ever meet are our human neighbours. So, as Jesus taught us, we ought to love our neighbours as ourselves!

  2. Loeb, A., Extra-terrestrial: The First Sign of Intelligent Life beyond Earth, Houghton Miffin Harcourt, 2021.
  4. 1 Thessalonians 5:21
  5. English, N., Origin Stories, Why Life is Beginning to Seem Very Special Indeed, Salvo #50
  6. Faulkner, D., UFOs & ETs; a Biblical and Cultural Exploration of Aliens, 2015, Answers in Genesis Press.
  7. Romans 8:28
  8. Romans 6:10
  9. 2 Peter 3: 7
  10. Ross, H, Samples, K., and Clark, M., Lights in the Sky and Little Green Men: A Rational Christian Look at UFOs and Extra-terrestrials, Nav Press, 2002.

Dr Neil English has a wide academic background in biochemistry, physics, astronomy and classical studies. He’s the author of seven books in amateur and professional astronomy. His new work, Choosing and Using Binoculars: a Guide for Stargazers, Birders and Outdoor Enthusiasts, hits the shelves later this year.

De Fideli.

Product Review: Hawke Frontier ED X 8 x 42.

Hawke Frontier ED X 8 x 42 Package.

A Work Commenced July 30 2023

Product: Hawke Frontier EDX 8 x 42

Country of Manufacture: China

Chassis: Rubber armoured Magnesium alloy

Exit Pupil: 5.25mm

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

Close Focus: 2m advertised, 1.94m measured

Coatings: Fully Broadband Multicoated, high resolution phase corrected BaK4 prisms 

Eye Relief: 18mm

ED Glass: Yes

Water Proof: Yes

Nitrogen Purged: Yes

Weight: 692g advertised, 701g measured

Accessories: custom zip-closed clamshell carry case, rubber rain guard and objective covers, lens cleaning cloth, neoprene neck strap, instruction manual and warranty

Warranty: Hawke World Wide Lifetime warranty

Price(UK): £449.00

In a previous review, I tested the Hawke Endurance ED 8 x 42, finding it to be a solid performer for the money. In this review I wish to report on the company’s more expensive Frontier ED X binocular, an 8 x 42 unit kindly lent to me by Steve at First Light Optics.

While the Hawke Endurance ED line offers very decent optical performance, their more expensive Frontier ED X range is a good step up in both optical and ergonomic quality. I spent a few months test driving the 8 x 42 and very much enjoyed the experience. What follows is a summary of what I found.


The magnesium alloy chassis on the Frontier ED X is drop dead gorgeous: small, light-weight (701g) and covered in textured rubber for excellent gripping. I elected to test a grey coloured unit, although you can opt for a more traditional green armoured chassis if you prefer. The focus wheel is the dream ticket; silky smooth, perfectly tensioned, accurate and precise, taking just over one full revolution anticlockwise to go from closest focus(~2m) to infinity and completely controllable with the lightest touch of one’s finger. Indeed, I would rate this particular focus wheel as one of the best in the industry! Kudos to Hawke.

The grey armouring and the red ‘X ‘logo make for a visually striking chassis.

The twist up eye cups are a good step up in quality from the Endurance ED models too. They have one intermediate step between fully extended and fully retracted and rigidly lock into place with a loud clicking sound. Eye relief is adequate for eyeglass wearers, as I was able to engage with the entire field with my varifocals on. The right eye dioptre is nicely grooved for easy adjustment but once set maintains its position well. Like the Endurance ED models, the strap lugs are quite large and protrude a bit more than I would like, but in my tests I didn’t encounter any such issues. The objective lenses are nicely recessed and treated to Hawke’s hydrophobic coating causing rainwater to bead and run off the lenses during inclement periods. Of course, it goes without saying that the optics are o ring sealed and nitrogen purged making it both water and fog proof.

The large central focus wheel is exceptionally smooth, with no free play or backlash.

The interior of the Hawke Frontier ED-X is immaculately presented, very clean and dust-free. I detected only a few very minor internal reflections when I pointed it at an intensely bright light source. There were no annoying diffraction spikes or diffused light around the same light source suggestive of the use of high-quality optical components. Comparing these results to those obtained with the lower-priced Endurance model, the Frontier ED X is certainly a step up in quality. Examining the exit pupils produced excellent results too, with nice round pupils and no light leaks in their immediate vicinity.

Left pupil. Note the very slight truncation at the upper right.
Right pupil.

Optical Assessment

The daytime views through the Hawke Frontier ED-X are very impressive: bright, sharp across most of the field and I was delighted to see well-defined field stops. Chromatic aberration is pretty much non-existent in the centre of the field, and I was only able to see an occasional flash of lateral colour near the field edges when glassing the highest contrast targets. The view is good, wide (a full 8.1 degrees) and engaging, thanks to excellent contrast and colour rendition. Star testing revealed mild field curvature off axis but even at the field stops, the images of stars were not greatly distorted. Those used to glassing with the Endurance ED models will immediately see the higher quality optics on these Frontier ED-Xs. The colour tone of the images garnered by the Hawke Frontier ED X is definitely on the warm side, with an emphasis on reds and browns. Closest focus is a very respectable 1.94m, so good for viewing butterflies, rocks and other targets in close proximity.

The twist-up eyecups stay rigidly in place and offer good eye relief for those who wear eye glasses.

The fast focus on this high-performance Hawke model makes it ideal for birding. Its excellent handling and the stable, relaxed views at 8x will bring you back again and again to this delightful instrument.  It’s obvious from a few minutes using this instrument that you’re dealing with a high-quality instrument with excellent ergonomic features.  The accessories are of very high quality too, with an excellent corduroy carry case, a test certificate and wide, neoprene neck strap and the company’s excellent no-fault lifetime warranty.

Any downsides? Well, I did notice some issues with glare when the binocular was aimed at strongly back-lit scenes which could be a deal breaker for some. The strap lugs stick out a bit more than most other models I’ve tested too.


Is it worth the £449 price tag? I’m in two minds about that. On the one hand, it’s a very nice instrument to handle, with well above average ergonomics, but optically I’ve seen as good or better performance from less expensive models. Finally, for those who desire the best centre-to-edge optical performance, you might want to consider Hawke’s flagship model – the Frontier APO – with built-in field flattening optics.


Neil English reviews hundreds of binocular models in his up-and-coming book: Choosing and Using Binoculars: A Guide for Stargazers, Birders and Outdoor Enthusiasts, which will be published later this year. He would like to thank Steve from First Light Optics for kindly sending the instrument for review.

De Fideli.