Archived posting to the Leica Users Group, 1996/10/04
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 09:13 AM 10/4/96 -0400, George R. Zachar wrote: >As light bending is pure physics, and film processing is pure chemistry, >there (by definition) is an objective explanation for the effects >sketched out above. The explanation is simple and derives from fairly basic physics. This was first thought out by Max Berek and was to remain a Leitz design philosophy into the 1980's, though newer designs are set to satisfy more traditional criteria. Berek realized that if the out-of-focus images had enhanced fuzziness, the in-focus portions would seem even sharper than they actually were. Therefore, his designs had residual aberrations to accomplish this, and the effect is to make the in-focus portion "pop out" of the print. Thus, the "Leica glow", as the Europeans name it, results. Leitz customarily tested their lens designs by a 'final image' standard and not by MTF, though this was to be adopted in the later 1980's and is now their norm. The addition of a Zeiss-trained optical engineer in the last several years as Leica's head of optical design has certainly established that all future designs will be to bench-test-performance standards. (Which may be why I'll continue cheerfully with my older lenses, as Herr Puts seems to have some problems remembering the history of Leitz and Max Berek.) Marc msmall@roanoke.infi.net FAX: +540/343-7315 Cha robh bas fir gun ghras fir!