Hi,
I have some misc thoughts going around in my head after trying out many bins in the last few months...
[1] 8x32 versus 8x42: Take any top brand 8x32. Compare it in the field with its 8x42 brother. There is no increase in magnification. The theory seems to be that the extra exit pupil is of no great advantage during the day (but admittedly it is in twilight). Assuming daytime use in various weather/light conditions, as opposed to twilight, will the 8x42 user clinch more ids in the field (particularly at longer distance) than the 8x32 user ? Feedback seems to say yes, but I don't really understand why... (there has been no mag increase and the extra exit pupil seems redundant...)
[The reason I ask is that I have an 8x32 (Leica BN) and have tried out a good few 8x42s of various brands. There is something about the 8x42 view which seems to show more detail, but am I imagining this ??? I'm not sure it's worth trading up for - although any excuses to invest in an 8x42 Ultravid gratefully received :-) ].
[2] Magnification: BVD and also this guy (http://www.birdwatchersdigest.com/optics/optics5.html) believe that a 7-8 power (let's say 8 power) reveals as much of the bird as is required for an id in the majority of situations. Do you agree ? My own testing indicates the bird is smaller but, assuming good resolution bins, can be identified in 8 power bins in most situations. The lower hand shake of the 8 power also helps. But is it my imagination or are more and more birders opting for 10 power binoculars ? Is it perhaps that the 8 power gives you the id (usually) but the 10 power gives you the better view of the bird overall (from an enjoyment/appreciation perspective)?
[As an aside I have tried several 10 powers in the last while. To my eyes, the Swaro 10x42EL had a funny rotating globe effect I just could not get used to, and both it and the 10x42 ultravid I found hard to hold still. I know others have these bins but they just did not seem right for me. Interestingly the 10 power I could hold steadiest was the Victory II 10x40. I think if I was going for a 10 it would be this one. Very sharp and bright also. Did not detect chromatic aberration (for example, when compared to 8.5x42EL Swaro where some CA was immediately visible in the same view (top of building against the sky)). Not sure about the rubberised eyecups. I thought after 20 mins testing outside the shop the skin around my eye felt itchy, but maybe it's just me.
Apologies if this has all been done to death in previous posts, but I just thought I would chip it in FWIW...
Niall
7x = wider fov, greater dof, easiest to hold 'still', less focusing required, very bright image at dusk;
8-8.5x = a good compromise = the most popular mag. by far for birders (imo).
10x = narrower fov, smaller dof, harder to hold still, less bright - esp. good if you're young.
The idea that you can see more birds with one or the other is a bit odd: it depends how far away the bird is! I should think any half-decent birder would find id'ing a bird similar with any.
Scampo beat me. I was going to say what he did, that the most important factor about focusing on the bird is how far away the bird is.
Is that you singing in that picture, Scampo?