It does apply but only to exit pupil not to actual light transmission of different glass which is what actually matters and totally different.
Take two scopes with same exit pupil now decrease the light transmission of one glass or add a coating that works for one eyes wavelengths and not anothers and you have a different story.. As mentioned the eye can only use so much light as can enter the pupil.
I know that per the formula and the transmission of glass that I have unusable light coming in from my scopes which is far better than not enough.
I agree with adjusting your scopes power setting to give you the best light performance at that exact time of day or daylight available.
Last edited by Strick9; 09/10/15.
