Thanks for the information guys. I have a good pair of 10x42 ELs that are about 10yrs old now, great for open country, bright skys and longer range viewing, but not optimal for winter skies, early and late, in/around woodland and crop field edges.... I do find the 10x42 fatiguing to use under these conditions at times, which I can't fully explain, but suspect that it is due to a combination of magnification, field of view and exit pupil size.
I can't decide whether the solution is to get something with lower magnification e.g. 8x which would increase exit pupil size and supposedly be easier to use, but lose on detail definition due to a smaller image scale. Or whether to stick with 10x and get a bigger objective, like a 10x50. Or whether to do both and go for something like an 8x56.
I am pretty sure that I want the largest field of view that I can find, which is basically higher than I have now:
10x42 - 4.2mm EP and 112m FOV.
The models that I have found that most closely meet these criteria would appear to be
8x42 - 5.3mm EP and 130m (Leica HD), 135m (Zeiss FL) or 136m (Swaro SLC HD) FOV 8.5x42 - 4.9mm EP and 133m FOV (Swar EL) 8x50 - 6.3mm EP and 117m (Leica HD) or 123m (Swaro SLC - discontinued) FOV 8x56 - 7mm EP and 130m FOV (Zeiss FL) 10x50 - 5mm EP and 115m (Swaro EL) or 117m (Leica HD) FOV 10x56 - 5.6mm and 110m FOV (Zeiss FL) I haven't had a chance to check models from Nikon or other makers yet.
Any thoughts?
You can tell that its been raining more or less solidly for 2 weeks now, can't you!