Archived posting to the Leica Users Group, 1998/11/25
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On Wed, 25 Nov 1998 AJSymi@aol.com wrote: > Tom wrote: > > snip "non-ASPH lenses, the 21-M 2.8, 35-M 1.4, 35-M 2.0, 50-M 1.0 and > 1.4, 75-M 1.4, 90-M 2.0 and 135-M 4.0, provide incredible three-dimensional > sculpting in a 2-dimensional image" snip > ----------------------------- > Tom, are you saying that a lens can't have the above qualities and score well > on 2-dimensional test charts?? > > Arturo > Arturo, Osterloh said in the previously quoted book that magazines would publish lens test results in which Leitz lenses did not rank first. He asked Leica users to not be upset, reminding them of their experiences with Leitz lenses and citing Leica's unique lens design philosophy (as of 1986). It's become well known on this listserve that the Noctilux, for example, tests very poorly on standard measures. Yes, there's some incompatibility between the characteristics the traditional Leica lens user looks for and admires and standard testing procedures. Dennis Laney in his book LEICA LENS PRACTICE (Hove, 1985) argues that an additional different type of testing is reuired for Leica lenses --one using the *edge spread width* criterion. On P. 131 he says: *The Leitz Lens Testing Laboratory ... set out to find a method for measuring the image forming properties of a lens that could be directly related to the photographic image. They started from the proposition that the subjects we photograph very rarely consist of grids of black and white lines on flat sheets of cards.* His Chapter 9 explains valid test methods for the old (and gold?) Leica lenses. P.S. I revised my e-mail because, in part, I left out in the list of lenses you snipped above what I think is the last great leica lens -- the latest 28-M 2.8. Thanks for you comment. I sure there are others who can answer your question better than I. Tom P.