A Work Commenced May 23 2022
Product: Opticron SR.GA 8 x 32
Country of Origin: Japan
Ext Pupil: 4mm
Eye Relief: 13mm
Field of View: 145m@1000m(8.25 angular degrees)
Chassis: Rubber armoured Aluminium & Polycarbonate
Dioptre Compensation: 5.50
IPD Range: 58-72mm
Close focus: 3.7m advertised, 2.84m measured
Prism: Porro BAK4
Coatings: Proprietary ‘N’ type differential multi-coating
ED Glass: No
Nitrogen Purging: No
Dimensions L/W: 10.1×16.0cm
Accessories: Ocular & objective lens covers, rain guard, soft leather carry case, padded logoed neck strap, instruction manual and warranty card
Warranty: 30 years
Retail Price: £199(UK) $315(US)
As I write these words in May 2022, it’s getting very difficult to source good-quality porro prism binoculars, especially in the smaller, compact sizes. Over the last few decades aggressive marketing has promoted the roof prism binocular with all its innovations, but with ever increasing price tags. That’s the road I largely followed in my exploration of the binocular market, until I decided to check out a number of porro designs from companies like Nikon and Opticron, who maintained several high-end models worth checking out. As I explained in previous blogs, it takes a lot of effort to create a roof prism binocular that can even approach the optical performance of good quality porro prism models. In this review, I’ll be demonstrating this proof of concept, by putting Opticron’s Japanese-made SR.GA 8 x 32 binocular through its paces.
Sourcing the Binocular
Perusing the Opticron UK website, I came across details about the SR.GA 8 x 32 model. Featuring a whole host of attractive features, including state-of-the art Japanese porro prim optics, a well made chassis and rubber armouring, all for an attractive retail price of £200. Incidentally, it’s available in the US for a retail price of about $315, but was discontinued as of May 2022. I contacted a member of the sales team at Opticron, Luton, and they were able to ship me out a unit. I was very excited when the package finally arrived, double boxed, with everything packed away well. What I received was the binocular inside an attractive, black leather case, together with a nice selection of high quality accessories, including a logoed neoprene neck strap, objective and ocular lens covers, a rain guard, a microfibre lens cleaning cloth, instruction manual and that all-important 30 year warranty(in the US it’s supplied with a Premier Plus Limited Lifetime warranty).
The reader will note that at one time four SR.GA models were being offered by Opticron: 8 x 32, 7 x 42, 8 x 42 and 10 x 42. The larger models appear to be discontinued and I was informed that they only had limited numbers of the 8 x 32 model available. Opticron state that these were updated versions of their earlier HR models, but I also found a source claiming that the SR.GA 8 x 32 in particular is optically identical to another model which just pre-dated the HRs, that is, the Dioptron 8 x 32. Here is the source of that information dated June 2018:
Many years ago I bought a pair of Opticron 8 x 32 Dioptron binoculars. These served me well for many years until I was seduced by the lure of roof prisms and sold them – a decision I have regretted ever since. Don’t get me wrong; I love the easy handling quality and balance of my 8 x 42 roof prisms, but I have missed being able to carry a small porro prism binocular that could be slipped into a jacket pocket.
The SR.GA is a direct descendant of the Dioptron. In fact, Opticron told me that the optics and mechanical elements are exactly the same. What has been added is better multi coating of the optical elements and the rubber armour on the outside. The result is a beautifully made (still in Japan), chunky little binocular that performs as well as a modern roof prism at three times the price.
It has bright, natural colours and that 3 dimensional image you only get with a porro prism.I would agree with another reviewer that the image is sharp for about 80% of the field of view and I couldn’t detect any colour fringing when looking at back lit objects.
Negatives? Not great for using with spectacles, no waterproofing, strap is ok, but nothing special, and while the case is nicely made, it is too tight a fit if you want to quickly take out or put away the binoculars.
In summary, high quality porro prism binoculars are pretty rare these days and you wonder how long Opticron will continue to sell this range.
Source: Amazon UK
As it so happens, I recently acquired a mid-1990s Opticron Dioptron 8 x 32, and even described some of its features and operation in this previous blog. Let’s take a closer look.
Here you can see both instruments from above;
Both instruments have the same size field of view, that is, 8.25 angular degrees. Both are also Japanese made.
In the next picture, you can see that they have the same dimensions. The Dioptron is unarmoured, unlike the SR.GA.
I reasoned the rubber armouring would add a bit of weight, so I compared the two on a weighing scale. Sure enough, the Dioptron tipped the scales at 494g, while the SR.GA weighed in at 543g.
The Amazon reviewer stated that the optics were identical in both models but the SR.GA had improved anti-reflection coatings. I can personally attest to these findings, as I’ve compared both in side by side tests.
In the next image, the coatings on the objectives of both binoculars are compared. The Dioptron shows a bright blue anti-reflection coating in normal daylight, while the more recent SR.GA shows much more subdued coatings, a good first sign that more light is being transmitted in the latter model.
Finally, you can clearly see the effects of adding the rubber armouring on the SR.GA compared with the unarmoured Dioptron. The latter is less well ‘padded out’ compared with the former:
And though there are small differences in the texture of the focus wheels in both instruments, I believe they are built round the same mechanism. The eyepieces are also pretty much identical in both models. In sum then, I think it’s a good bet that the SR.GA is indeed an updated version of the Dioptron 8 x 32.
The SR.GA is a very finely made instrument. In the hands, it feels very solid, with the rubber armouring helping the user maintain an excellent grip. The oversized focus wheel is covered in fine rubber and is exceptionally fast, moving from close focus to just beyond infinity in less than half a turn(actually about 160 degrees). Some super fast focusers make it easy to overshoot by accident, moving past the ideal focus position too easily. This is never a problem with the SR.GA 8 x 32 though; the gearing and tension is just perfect for high speed focusing. There is no backlash or free play either. In short, this is one of the nicest focusers I have had the pleasure of using in a binocular in this size class!
The dioptre compensation ring is located under the right ocular. It’s adjusted by rotating it slowly clockwise or anti-clockwise. It’s not quite as well tensioned as the Nikon E II 8 x 30 I recently showcased, and, as a result, it does tend to wander a wee bit in field use. This can be easily remedied by wrapping a small elastic band round the ring. For me, I just remember my preferred position and make slight adjustments every now and then when required.
The eye relief on all these classic, compact porros is poor, it has to be said. It has a value of just 13mm on this model. That’s not an issue for me, as I don’t wear eyeglasses while using binoculars but those who must wear eyeglasses will find viewing the entire field problematic. I checked this by turning down the rubber eyecups. I could not image the outer part of the field while wearing eye glasses. Just like the Nikon E II, spectacle wearers will benefit from using more contoured glass lenses with high-index glass.
Just as the thick rubber armouring will help protect the instrument against knocks and light rain, the deeply recessed objective lenses also confer quite a bit of protection against aeolian-derived dust, rain and stray light.
All in, this a very delightful instrument and a real joy to use.
As always, I began my optical testing of the Opticron SR.GA 8 x 32 by turning my IPhone 7 torch up to its brightest setting and examining the images as seen visually from across my living room. The results were good. There were no diffraction spikes and only a few slight internal reflections in evidence, with only a trace of diffused light observed around the light source. Compared with the older Dioptron 8 x 32, it was a far cleaner result. Later, I turned the binocular on a bright, yellow sodium street lamp and did manage to detect some very weak internal reflections. In this capacity, it was a notch down from the excellent Nikon E II porro prism binocular previously tested. Turning to a bright gibbous Moon low in the southeast, I was pleased to see that these internal reflections were quite well subdued. This will be a good instrument to follow the phases of the Moon with, and for observing cityscapes at night.
My next test was to photograph the light emerging from the exit pupil in both binocular barrels.
As you can see, the pupils are round and untruncated, with only minor light leaks around them.
Testing under the stars showed the binocular to be very accurately collimated. Just focus on a bright star like Vega, and defocus the right barrel image using the dioptre ring. The focused right barrel image of the star was seen very near the centre of the de-focused anulus, indicating very good alignment. I detected a modest drop in illumination as a bright gibbous Moon was moved from the centre of the field to the extreme edge, but all within design tolerances.
The Opticron SR.GA 8 x 32 serves up a really good image during all daylight conditions. It’s bright, with excellent sharpness across about 70 per cent of its very large field(8.25 angular degrees). The outer 30 per cent of the field shows progressively more field curvature and pincushion distortion, but not to the extent that it is distracting. Contrast is excellent, as is colour saturation. I found comparing it to the older Dioptron model to be eye opening(excuse the pun). The latter image was quite yellow and less bright in comparison to the much more neutral colours served up by the SR.GA. This probably indicates that its light transmission curve as a function of visual wavelength is flatter and brighter in comparison with the Dioptron. The other thing that was noticeably improved was glare suppression while looking near a setting Sun. The SR.GA was far superior to the Dioptron in this regard, and the same was true when testing for veiling glare. That said, the SR.GA was not quite as good as the Nikon E II 8 x 30 in similar, side-by-side tests.
Colour correction is excellent: I detected none on axis and only a trace when examining high contrast objects, like a telephone pole set against a bright, leaden sky.
As I’ve come to expect from a high-quality porro prism binocular like this, the instrument manifests vivid 3D images of the landscape over short and medium distances. Like the superlative Nikon E II I recently showcased, there is very much a sense of ‘focus and forget,’ especially when trained on targets beyond about 30m or so. I measured its close focus- 2.84m – to be significantly better than the advertised 3.7m. Just like the Nikon E II, scanning large swathes of landscape with this instrument is supremely comfortable, with no blackouts to mention and no rolling ball effect.
As a stargazing binocular, I enjoyed lying out on a recliner in my back garden in the wee small hours of an early May morning, scanning the summer Milky Way through Cygnus. Stars show up as lovely pinpoints of light across most of its expansive field, against a dark sky background. Though not the best instrument for binocular stargazing, it still showed me pretty views of the Coat Hanger asterism in Vulpecula, the great globular cluster M 13 in Hercules, and some lovely views of the colour contrast binocular double O^1 Cygni. This will make a rather good instrument for enjoying the up-and-coming Perseid meteor shower when truly dark skies return to our shores in early August. It has also presented some lovely, high-contrast images of the crescent Moon and earthshine, as well as tack-sharp images of crater fields and the lunar maria.
In summary, this will make an excellent general purpose instrument for my needs. Though it’s not waterproof, it’s most certainly a tough little binocular, and ergonomically is very easy and intuitive to use. I have already enjoyed many hours with this instrument, surveying the hills around my home, exploring woods and forests, rivers and ponds, and also for scanning trees and bushes for small, passerine birds.
Comparisons Between the SR.GA and the Nikon E II
One might legitimately ask why one would use the SR.GA in preference to the Nikon E II and vice versa? Optically, the reader might be surprised to learn that the views are much more similar than they are different. Both instruments have excellent central sharpness with nice big sweet spots. Both have excellent colour correction and very similar colour tones. Both have really good control of glare. If I were to nail it down, I’d just say that optically, the Nikon E II does everything that little bit better than the SR.GA. But optics are only half the story. I prefer the handling on the SR.GA. It just fits my hands that little bit more securely. I favour the super-fast and precise focuser on the SR.GA over that accompanying the Nikon E II. Indeed, I think the Opticron makes for a better birding binocular than the Nikon for this very reason. The SR.GA also has better ‘hang’ than the E II, meaning that it sits more flatly against my chest than the Nikon wonder bino.
So, for me, it’s not really a question about which instrument I prefer. I’m a little old-fashioned and just a little bit sentimental. A cursory perusal of the literature of 20th century birders and naturalists, shows the 8 x 30 emerging as a spiriting gestalt, connecting very different people in very different circumstances, across the fields and the years. So, I count myself extremely lucky to own both and hope to use the SR.GA pretty much routinely, while the Nikon E II will be reserved for more special occasions, when the mood takes me. Indeed, I hope to write extensively about my experiences with both these neoclassical porro-prism beauties in future blogs and elsewhere…….
A Note on Storing the Instrument
While the case that accompanies the SR.GA is very nicely made, it’s a bit of a squeeze to get the instrument into and out of, especially if I want to be out the door fast. I’ve thus decided to store both my compact porros in small air-and water-tight plastic tubs. Lining the inside with a plastic bag, I have also included several sachets of activated silica gel. By activated, I mean the sachets are placed in a low power setting of a microwave oven for several minutes to drive off the absorbed water from the silica gel pellets. When the blue coloured crystals turn orange-green, you’re good to go. I’m also in the early stages of experimenting with a possible fungicide; camphor, which has well established fungus killing properties. I think the instruments might well benefit from a ‘camphor bath’ every few months or so for 7 to 10 days to curtail any fungal growth which may set in over the long term. For travel and vacation though, the black leather Opticron carry case should serve me fine.
It’s a great pity that quality, Japanese-made porros like these are becoming as rare as hens’ teeth. I for one have been won over by their optical and ergonomic charms and would heartily recommend them to anyone. And while great roof prism binoculars will always have their place, the world is big enough for both families. In this capacity, I have submitted a proposal to pen a brand-new literary work – Choosing & Using Binoculars – showcasing the many and varied binoculars now available on the world’s stage, a work that will help as many people as possible make good, informed decisions on choosing and using the right model for their intended purposes. There will be plenty in it for everyone: birders, hikers, general nature enthusiasts, mariners and astronomers….and for all budgets. The proposal has now been approved and will be published as a fully-illustrated, stand-alone text by Springer Nature in late 2023.
I hope you will support the author in this project.
Thanks for reading!