Originally Posted by spdrman
I've been looking alot into spotting scopes and cant decide what I want, it will mainly be used for backcountry mule deer hunting, Price isnt an issue and I was set on buying a Swarovski 20-60x65 but I've also been considering the Zeiss Dialyt 18-45x65 because it looks like it would be easy to stuff in a pack with its straight body design, both scopes are within a 1/2" on length and are within 2 ounces on weight
My concern is the max 45 power on the Zeiss? Am I going to regret not having 60 power when trying to judge mulies between 700-1200 yards? or will the 45 power be enough?
Or should I not even worry about size and weight and just buy the Swarovski 20-60x80? Is the bigger objective worth packin around another 10-12 ounces??
think mof it this way: Divide the lense diameter with the power. This gives you the actual light transmission you'll see. Ideally you want a factor of three. An 82mm lense divided by 27x gives you 3.03. The same lense divided by 45x gives you 1.82. Ok, but getting somewhat marginal. Kowa is now selling an 88mm lensed scope that will still only give you 1.95, but still better. A 20x scope with a 60mm lense will give you about 3.0, but with a field of view loss in that matters a lot. I use an 82mm lense with a 27x eyepiece, and that's a very bright scope to look thru. It has all the resolution I ever could use.