I was wondering if someone would be able to help me understand the statements quoted below, which are at BVD, where a 60/65mm scope can outperform an 80mm in "bad" conditions. I think I understand how lower magnification may help regarding the appearance of the view, but don't understand the science behind the smaller aperture. If I placed a piece of cardboard with 60mm opening on the objective of the 80mm scope, would it help in "bad" conditions?
Thanks in advance for any insights.
Jason
Thanks in advance for any insights.
Jason
Nikon Fieldscope III ED & 20-60x Zoom | Better View DesiredI remain convinced that in 95% of birding situations, an exceptional 60 mm scope will show you all there is that you need to see. In a very few situations (dirty air, unstable air, or fog) the 60 mm scope will actually outperform the the bigger scopes at equivalent powers.
The Ultimate Birding Scope! (2 of them) | Better View Desired"My feeling is that 65mm is a kind of threshold; that, in fact, a 65mm scope may provide all the detail and brightness the human eye can use in all but the most extreme conditions. It would have to be nearly dark for the 80mm scope to show a clear advantage. Then too, in terrestrial viewing where some combination of heat haze, fog, and dust...dirty, wet, unstable air...is too often the real limiting factor in the view you are able to get, going from 65mm to 80mm is not going to help and may, in fact, hurt. A smaller scope, as I have pointed out before, can actually outperform a larger one in bad “seeing” conditions."