I have a number of bins, but the ones that see the most use are as follows:
Leica 8x20 Ultravid -- for ultralight travel or any time I don't expect to be birding/butterflying but could end up seeing some good ones (e.g. while primarily doing photography, or while walking to work during migration).
Browning 8x32 -- for birding+butterflying on bicycle rides, carried bandolier style on a long strap or in a trunk bag.
Zeiss 8x32 FL -- for most butterflying+birding, and for most travel
Swarovski 8x32 EL, 8.5x42 EL, or Leica 8x42 Ultravid -- for birding outside the butterfly season. I like the optical quality of the big EL best but it is nonSV original slow focus version so it is only suitable for mid and distant birds such as while cruising roads in wildlife refuges. The little EL (nonSV, nice focus ratio, hydrophobic lens coating) is best for close to mid distance fast-paced birding in brushy grassland or woods in late fall and early spring and for birding in rain. The Ultravid is best for mid-winter birding since the focus is unaffected by very low temps (it is regularly below zero F where I live in MN, and I've used this Leica down to -40 degrees F).
If a full-sized alpha 8 or 8.5x bin had 5 ft close focus, open-hinge design (which I prefer ergonomically), wide FOV, flat + astigmatism free field, low rolling ball, hydrophobic coating, and fast but precise focus (even in the extreme cold), I would be tempted enough to buy it and it would become my do-all, primary bin. I'd keep the Leica 8x20 and the Zeiss 8x32 for travel, stop using the Zeiss as my usual warm-season bin, and keep the Browning for knockabout uses. All the others would become redundant. I'm still waiting for such a bin. The Swarovski SV EL and Zeiss SF come closest but they aren't perfect (esp. that slow focus ratio!) and so I'm not biting. One of those two could replace some of what I'm using now, but I'm not tempted because I already own this set. But I'd go for the SV or SF if they were revised with a more functional focus ratio.
--AP
