Archived posting to the Leica Users Group, 1997/12/07
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>So generally the effective resolution is lower than the theoretical >resolution because the effects of optical aberrations are more destructive >than the diffraction effects, even at smaller apertures!! >Erwin I knew it! Some years ago there was a letter to Pop Photo. The photographer asked if they could suggest an explanation for why an old Tessar (on a view camera, I think) looked sharper at small apertures than some super expensive new lens of the same length. PP dragged out the tired old diffraction limit. There can't be any difference-end of story. I have seen other claims in print that by the middle apertures lenses all perform about the same. I never believed it. I know there are aberrations which are not affected by aperture, and that contrast differences influence sharpness as much or more than resolution. Have you (or anyone) found differences between lenses used at small aperture openings which would be noticible in regular use? Nick Hunter