Archived posting to the Leica Users Group, 1996/09/04
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> I just looked into the plastic tub my 1972 Russian 85/2 LTM lens came in > and there was a certificate in the bottom, which calmly states that the > central resolution is 33 lines/mm and edge resolution is 18 lines/mm. > I haven't seen the results of this lens in real life yet, but this > cetificate makes me wonder about it. Even medium format lenses seem to > typically have about 90-100 lines/mm central resolution. Even the > Lubitel in Amateur Photographer tests got 90 lpm for the central area... > I think I must be comparing different testing methods. Any comments? Are your sure to compare camparable figures ? Maybe the Russian 85/2 is refering to pairs of lines/mm. I agree that even in terms of pairs of lines/mm, 33 and 18 are quite poor results, but I highly doubt that a Lubitel reaches 90 lpm. 90-100 pair of lines/mm is an exceptionnal figure, obtained only with top quality lenses (most of the 50mm from all brands, some Canon, Nikon lenses and - of course - Leitz lenses). -- Francois Jouve (Francois.Jouve@polytechnique.fr) Centre de Math. Appliquees, Ecole Polytechnique, 91128 Palaiseau (France) http://blanche.polytechnique.fr/users/www.jouve/jouve.html