In order to stimulate more technical, intellectual discussion on the optical properties of lenses on different formats, I have started this thread stemming from the initial discussions here:
https://www.pentaxforums.com/forums/general-photography-industry/209882-next-...pentax-16.html
Now, aperture on a lens, let's say a FF lens like the FA 31mm f/1.8, should theoretically be constant between all the formats used to shoot with this particular lens. i.e. an f/5.6 setting on the lens should mean f/5.6 despite using the lens on an APS-C, Q or FF format. The crop factor alters the apparent aperture according to the FoV, increasing DoF with smaller formats than FF (considering the crop factor of FF is 1.0). But the actual aperture of the lens remains the same.
Is there any more to the optical qualities of the lens than this, or does the different sized formats actually somehow change the lens's characteristics?
Last edited by Ash; 01-06-2013 at 07:54 PM.
Reason: spelling