Kahles is an Austrian optics manufacturer that's been around since 1896, but in the bird watching world it seems virtually unknown. The company had been owned by Swarovski since the '70s but apparently operates independently. Their website makes great claims for their in-house capabilities, but for the binoculars at least, I suspect there might be some common ground.
I've been been curious about this make for some time but never seen them at usual optics shops I visit or birding shows. I've been fortunate to borrow a 8x42s for a couple of weeks for evaluation along with two comparably priced models from other brands which are also generally hard to find in the UK. Individual reports on those are also in the review section but a more detailed comparison will be posted in the general binoculars forum.
Kahles produce only three binoculars, an 8x32 and both 8x and 10x42. There is nothing on the Kahles website to indicate it, but it looks like the range was revamped around 2012, reducing weight, increasing transmission and adding 'oliphobic' coatings. I've no information on what oliphobic means but imagine it's something to do with keeping the lenses clean. There is nothing on the binocular either to indicate a version but from it's weight it is the latest model I have. I've not found a recommended retail price either but it looks like the x42s are around the 800 mark but advertised prices vary quite a bit, but it's not always clear if it's for the pre or post 2012 update.
The 8x42 looks quite a classy binocular in 'Loden Green' with grey rubber eyecups and focus covering. Apparently Loden is the the colour of a traditional Bavarian fabric, but looks very similar to the colour Barbour uses for it's jackets
The design is reasonably compact and light for a binocular of this class and very much in line with my personal tastes. The slim tapered barrel design is a particularly good fit for my hands, with plenty of finger overlap, specially on the focus, which is important as I'll explain later. The strap lugs are well positioned and did not interfere with the grip like they can on some models. The surface design on the armour is low profile and simple and I imagine the sculpted indents on the underside might be useful for thumb positioning for some, but didn't quite work with my hands and settings. The armour material has a fine textured finish has a good secure feel to it but I've avoided trying it in the wet. There is probably going to be a lot of composite plastic in the construction at this weight but still has a very robust feel.
The eye relief is listed as 19mm and I think all of that is available. That's more than I need with my glasses. There are no intermediate steps on the twist up eye cups, but there is enough resistance to hold position so far, though I'd probably fix the correct position with an O-ring. Not unusual as I generally need to do this with most binoculars. Without glasses the fully extended standard eye cups are too short but still sit comfortably on the edge of my brow feeling secure and stable. Alternative winged eye cups are supplied which might provide a better fit and light shielding for some but I didn't find them particularly comfortable.
My main ergonomic niggle is, out of the box, the focus tension was far too stiff. It makes what should be a reasonably fast focus seem slow and hard work. It fact it was a two finger job to start with. It has eased up a lot with a few days of use, and seems likely to get better still but still has a way to go to satisfy me. Other samples may be better. The dioptre adjustment, on the other hand might be more secure if it was a little stiffer.
Now the really good point. I particularly value binocular sharpness, and this is where the Kahles does shine. It really is at least as good and probably better than a number of examples of premium models I've tried and certainly their second tier offerings. There are candidates from other brands what might match it, (as my other reports show), but clearly better than the majority of mid-priced models I've tried. My resolution testing confirms it's in the top league.
The colour neutrality and vibrancy is also very good. Perhaps this is where the relationship to it's Austrian parent is most evident. In common with their models it did make certain straw coloured subjects in particular appear whiter than the other models compared and very reminiscent of the Swarovski EL and SLC I've tried, but I've not done a direst comparison so take that with a pinch of salt. Some might describe it as brighter but I suspect it's just due to differences across the transmission spectrum, although it did seem to do marginally better than other pairs in my possession in one low light comparisons, but in others it was indistinguishable. Their literature claims over 90% transmission, optimised for 500 to 550nm. I don't have access to spectroscopy but there are indications that the coatings are very good indeed.
The field of view is listed as 6.3, 110m/1000m though my estimate was a fraction better. This is a narrower apparent field of view than the 8x32 and 10x42 they offer. With many 8, 140m 8x binoculars on the market this does sound unusually narrow for a binocular at this price level. In practice there is little field curvature and the view retains good sharpness to the edges. As a consequence the view didn't feel particularly narrow at all, in contrast to several cheaper models I've tried with similar specifications. They also have a very good resistance to glare. I could get a little veiling at the edges of the view at angles very close to the sun, but I really couldn't detect any contrast reduction. Stray light control appears very good.
Although the Kahles doesn't feature ED glass I would still have expected lower chromatic aberration (colour fringing) in a binocular at this price. The great majority of the time it was not evident at all but in a occasional high contrast conditions it could occasionally be a bit troublesome. Careful eye positioning would keep the centre fringing free but it could be quite pronounced in the periphery. I should emphasise that I only found this noticeable at specific occasions. Users do vary in their sensitivity to CA and some users might find it more acceptable than other.
I estimated the near focus on this sample to be 2.06m, a bit better than listed, and it takes about 1.1 turns anticlockwise to infinity. This would normally equate to a fast focus, but it didn't fee that way with stiff focus on this sample.
Kahles offer an 11 year warranty with both parts and labour covered for the first five years
It's tempting to consider comparisons to the Swarovski models. I've not been able to look at them side by side but there are clearly a number of design decision intended to place the Kahles at a lower price point than the EL and SLC. A set of compromises that I personally think are well judged, keeping a couple of the best bits.
At the price, some will expect the technical bell and whistles claimed by some competitors, but It's sharpness, size, weight and colour rendition are very much to my liking. However, for birdwatching, I'd certainly want a lighter focus and ideally lower CA than I found on this sample. In spite of the niggles, overall I found this binocular very appealing and desirable binocular.
Obviously there are other candidates at this price level, particularly from Germany and Japan, that are worthy of consideration as well. I'm posting reports on a couple of them.
I have checked out this model only to satisfy my own curiosity and there has been no incentive from any source to do so, though I do need to thank the person who generously loaned this model.
David
Link to comparison: http://www.birdforum.net/showthread.php?t=272946
