A reply I gave in another thread may have got lost there, so I am posting it here again. I did an extensive evaluation a year ago, and I have since bought two binoculars. Yet, I am still very much interested in comparing the various models, in particular those I had no chance to check last time. Therefore, I grabbed the opportunity for another comparison as copied below (appologies to whoever read it in the 32 vs 42 thread):
I have just had another chance to compare a number of top-brand binoculars under low-light conditions. I concentrated on the 8x models of Swarovski (EL), Leica (Ultravid) and Zeiss (FL). The Zeiss 8x42 FL was clearly the one that came out on top, both for overall brightness and contrast. It was also clear that the x42 models were brighter than the x32 (including the FL). And the otherwise fine 8x20 Ultravid dropped off considerably. This is actually what one would expect, but as many comparisons are made under conditions of full daylight, one then finds reports that objective diameter is not critical. My test has clearly convinced me that carrying around a certain amount of extra weight is worth it.
I should add that the conditions were such that colors could still be very well seen in all glasses and also with the naked eye. Thus, these were by no means borderline conditions. Rather, conditions were about what you find while birding in the late afternoon in a forest when it is overcast.
__________________
Makes sense! I guess thats why the 40mm has always been the birders standard!
[QUOTE=Swissboy]
I should add that the conditions were such that colors could still be very well seen in all glasses and also with the naked eye. Thus, these were by no means borderline conditions. Rather, conditions were about what you find while birding in the late afternoon in a forest when it is overcast.
__________________[/QUOTE]Hi Robert
I'm still not quite entirely convinced that the extra brightness, such as it is, really affects the identification and enjoyment of birding; surely few birders follow their hobby into the deepening gloom of dusk? It's only then that any worthwhile differences are noticeable in my own experience of using the 8.5x42 Swaro, 10x32HG Nikon and 10x25 Ultravid.
I have found, equally unsurprisingly, that the 60mm Swaro scope is less bright than the Zeiss 85mm - but the difference is surprisingly little and again, is only truly noticeable at late dusk. Again, I didn't think that this affected my ability to see the gulls in the roost I was viewing (I'm pretty useless at id'ing them whatever the size of scope).
I would agree that to carry round extra weight is worthwhile on a short walk, especially at evening, but not on a hike. On balance, if I was recommending binoculars, I think I'd suggest a 32mm objective size for overall comfort.