Very interesting writings Tom, food for thought. I’m in my 7x period. Bought 3 the last months: Leica UV HD (not +), Trinovid BN and -the latest member of the gang- a beautiful FL in green. It will take some years to test this three lovely optical instruments and I wouldn’t mind to add a BGAT but they very hard to find. Don’t let go of yours this time!It's now just over twenty-four hours since the 7x42 Dialyt BG/AT*P* was handed to me by my local posties — they go round in their red van in a cheerful, very helpful man and woman team; very sweet, so that got me off to a good start even before I opened the box.
Anyway, here are my thoughts after two or three hours of neighbourhood testing: yesterday in bright and hazy-bright sunlight with the sun behind and to my left, then a bit later with the sun low and in front to the left and not visible by me through a window nor through the binoculars. Also later on after dark I couldn't resist a bit of casual indoor testing aiming at a table-light fitted with a four slanting but straight-sided lampshade. This shade is semi-translucent in a warm tan colour and glows orangey from the bulb inside. On the sides of the shade are maps of London, printed in black and taken from hand-drawn work of centuries gone by. These are a great test for me of resolution, contrast and glare. The viewing is not easy, as one of the features of the Dialyt is a relatively long close focus distance of around 11 feet. Even with only a slight dioptre correction I can't focus it at much less than 20 feet — someone please tell me if there is an obvious mistake I am making!
Additionally — and I mention all this for relevant reasons — the top of the shade is open in a square shape, which gives rise to glare possibilities, and so as well as viewing mainly through the Dialyt I did find time to try a few other glasses to compare it against. Mainly though it can be a challenge to read small handwriting against the light at the end of the day, after already putting in a good few hours of glassing.
If it isn't obvious already, this wasn't and won't be a scientific test and also my observations are skewed no doubt not only by ageing eyesight but also by subjective conscious or unconscious biases.
Here goes... On first taking the 7x42 out of the box, I was struck by features I had always liked but had not always remembered clearly in the intervening time since I last held the bins: remember that this turned out to be the very same unit I had sold in 2020 or thereabouts. Foremost I noticed again how long and thin the barrels were compared with modern roofs. Second, and for me a massive plus point, the balance in hand was the best of any 42s I have held and arguably even better or at least as good as the EL 8x32 Field Pro, another open bridge design which I picked up later in the day to compare on this. Leading on from that, once I started to view through the glass the hold was never tiring, always steady. That lack of getting tired is important to me as shakes can set in quite early and are something that make most 10x instruments a no-no for me, and similarly 50/56's as I can't hold them still. The EL / Dialyt comparison made me think that possibly (I have heard this somewhere — Lee, I think) Swarovski used the Dialyt design as inspiration for their open bridge EL models. Unlike Roger Vine I have always liked the appearance of the Dialyt, probably as its form aids its function so well. I like the 8.5x42 EL open bridge binoculars as well but their forward-tipping balance is a point against it.
Along with the balance and hold I suppose eyecups and focuser and IPD should feature as part of the handling experience. I don't wear specs for binocular use though I do for almost everything else: driving, reading, and usually when out walking, or just being indoors. So the long extended hard rubber eyecups are perfect for me; no need to fold them down and they make for relaxed viewing. IPD tolerance again fits well for me and so the instrument really just stands back like a discreet servant and lets me enjoy the viewing in comfort. This became more apparent when I started looking through my two other 7x42s, both legends in their time and often mentioned on this forum: the Victory FL and the Ultravid HD Plus. Both comfortable and nicely balanced but for me in second and third, or equal second place for their ease of hold. They don't have the same feeling of weightlessness. I appreciate that this weightlessness is often taken as a negative attribute; hence many birders avoid compacts and even 32mm binoculars. Compared with a modern roof such as the FL or even more a Nikon the Dialyt's focuser needs a touch more push or pull but in the case of this unit the focuser has been greased, if not during its 'absence', then at least within the last four years as Gary Hawkins serviced the unit two or three years after I first bought it. The main thing is that it turns evenly, resistance does not vary in one direction i.e. no 'stiction', and also resistance does not alter with a change of focus direction. In use yesterday I did not notice any focus irritations as the focuser felt nicely greased. Apparently they generally do dry out eventually and need regreasing as I could tell at the first time of purchasing — hence the service mentioned above.
Optics. Some optics work for me right from lifting the bins to my eyes; others need a bit of settling in time; and either way that can change from day to day depending on how much close viewing work I've done in reading, using the computer, and so on. The Dialyt worked for me immediately. It just seemed such an easy view. Only when making a direct comparison with the FL could I tell it probably lagged a tiny bit behind, but to my eyes (still good but not as good as they were) the difference was very hard to pin down, perhaps just as in those discussions about perceived or not perceived differences between UVHD (white print logo) Leicas and the later Plus (red print logo) Leicas. Considering that the Dialyt presumably does not have FL/HD glass even in the latest T*P(*) version this is very impressive. ADDENDUM: just after completing this write-up I tried the BGAT again alongside the FL and the UVHD Plus 7x42s and while I stick by my very positive impressions of the earlier glass I can see that the newer instruments are ahead, though this is only apparent to me in direct comparison.
Chromatic aberration. I'm going to duck this one but since Roger Vine says in his review that external focusing binoculars are less affected by CA I'm happy to say I didn't notice any, recently or in the past with this binocular. In general I tend only to notice it in any instrument when panning, which doesn't happen often in my usage, or when looking at a print of a photograph. Similarly I am not a connoisseur of rolling ball (Globuseffekt).
Easy view. I'd have to say that so far I have found the view even easier (though I wouldn't say better) than with the Leica UVHD Plus, which is famous for its easy view, at least in the 7x42 model. This could be for various reasons: one, same as the FL it has a wider view than the UVHD series; two, I'm probably a bit carried away by the joy of suddenly finding myself back with the one glass I really wished I hadn't ever parted with; and three, though I never found the Leica a glare monster (after all, most binoculars will get glare in some circumstances), yesterday's testing later in the afternoon as the sun came round from behind the shoulder to front-side set off a little bit of obstructive and resolution-dampening glare in the Leica that didn't show in the Dialyt. This is one area though where I used to think the EDG 7x42 was a clear winner. I say 'used to' as it had minor flaws in other respects and I was happy to part with it before it needed any service attention.
Indoor findings, using the lampshade mentioned above. Standing back a good 18-20 feet in order to keep on the right side of the Dialyt's minimum focusing distance, it was fairly easy to focus the glass on the black impression of rivers on the lampshade's straight-but-slanting-sided map. Some of the words and place names would have been hard to read even at that distance as they are reproduced with varying degrees of contrast and legibility on the map but as I already know what they say, even allowing for flexible old English local spelling, I could discern them at least satisfactorily and by taking the chance also to focus on other objects in the room such as curtains, book bindings, cushions, and various textiles I could clearly make out textures and colours in sharp definition. Of course these binoculars are all designed with hunting, birding and general outdoor use in mind, so these findings are in some ways irrelevant. Just to say that the modern 7x42s FL and UVHD Plus definitely showed they had the edge in this situation, though glare was still a small problem and the Dialyt's behaviour was perfectly acceptable. Contrast seemed to be stronger in the FL in particular; I couldn't decide when it came to the Leica though in indoor use as well as outdoors I particularly like the Leica's rounded and vivid colour representation.
At this point everything is starting to whirl round in my head so I'll bring this to a close. In a nutshell this 7x42 Dialyt BG/AT*P* is a fine instrument, in very good cosmetic and optical condition for its age (mid to late 1990s) and I'd say a definite keeper for its balance and ease of handling, its sturdy construction and focuser, rugged good condition rubber armouring, easy bright 7x42 optics with Abbe-König prisms, and simple dioptre setting by means of a rotating sleeve just below the right-side eyepiece. There is nothing flimsy: no squishy imprecise eyecups HT-style, the dioptre sleeve is solid and smooth turning, the armouring is robust and strongly fitted.
The rainguard is a masterpiece: a one-piece hard rubber inverted tray that just lands easily on top of the eyecups when allowed to drop down along the slotted through straps on left and right. No clicking or squeezing on or off.
In summary I'd say that for me the combination of good points outweighs the few areas where the Dialyt design has to concede to modernity. Dust can get in as it's not a sealed unit; in fact some (though not much at all) has got in, and — in theory but I hear not so often in practice — water and damp can make ingress and therefore there is a risk of mould if attention isn't given to careful storage and atmospheric conditions when it's not in use. But in actual use right into dusk I can't believe anybody really needs much more for enjoyable birding and successful ID'ing. Am I going to start selling the more modern bins? On the whole, no. I might let go one or two, such as a 10x42 that I can't hold too steady, but otherwise this has been a very enjoyable reunion and re-addition alongside some more modern glass that is already of proven ability and usefulness. And I enjoy the ones I have.
By contrast I wonder if any of you have had this model and just not got on with it. It would be interesting to hear your story and why you moved on and looked for something to replace it with.
Corrections made 24/2/23 at 20:30 GMT for minimum focus distance typos. If this were my only bino I'd find the lack of close focus a drawback but not a dealbreaker.