ORIGINAL: GMMAT
First Dan....ya gotta know what sac riding is to define it (your post is a good definition
). Second....no...I'm not trying to get a rise out of him. Whena person asks a question in an information seeking thread.....and someone mentions that 8.5x50's are 100X better at low light gathering capabilities than 8x42's....I think a little clarification is in order. I'm also guessing the quality of your glass is a BIG factor in ANY of these optics threads.
In bowhunting situations....I'm not even sure larger is better (in either the magnification of the FOV numbers). Someone mentioned Matt/PA being a pretty good resource on this. I'll defer to him for clarification of what I'm attempting to say.....but "bigger" isn't necessarily better for bowhunting.
Or I may just be too old to understand all the hyperbole you kids rap at each other with these days. Highly plausible.
I'm new here.....but I was an opticalman in the navy and made a living for several years servicing optics including thousands of pair of binoculars. I know optics. The article Spearchucker posted by Mark Mazour is excellent.
I'll tell you what I use. I have an 8 X 42 roof prism bino. I live out west in NM and find few situations where the 10 X would be an advantage. 10X gives a smaller exit pupil, a smaller FOV, and is harder to hold steady enough to really make that extra power worth having IMHO. Now I know alot of ya'll have 10 X binos but my recommendation would be to go for the 8 power with the 42 or 46 mm objective. The FOV, and twilight factor, on an 8X far outweights the power on a 10X.