Archived posting to the Leica Users Group, 2000/02/13
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]- ----- Original Message ----- From: Dan Cardish <dcardish@microtec.net> To: <leica-users@mejac.palo-alto.ca.us> Sent: Sunday, February 13, 2000 5:33 PM Subject: Re: [Leica] Apo-Summicron-M 90/2.0 ASPH tested by CDI > Are you looking at the same MTF charts that I downloaded from the Leica > site? The APO 90 MTF at f2 looks excellent, at least the way I interpret it. > > Dan C. > > At 05:03 PM 13-02-00 +0100, dominique pellissier wrote: > >> > >################ > >On the official Leica site, there are some MTF tests. > >If you see the test of the apo90, there is no doubt : at full aperture, this > >lens is not an absolute winner. > > > >Conclusion : don't buy the apo90 if you have the old90. > > ########### Yes. At full aperture, the contrast is 52 %. At 5.6 : 72 %. Great difference. By comparison (yes, i know, it's not very rigorous to compare lenses of different focal lengths) the 2.8/180 apo gives 82 % at full aperture and 82 % at 5.6. Now, let's see the CDI tests for these 2 lenses. For the apo90 : good (center), good (edges) at full aperture and excellent, very good at 5.6. For the apo 2.8/180 : very good, very good at full aperture; same results at 5.6. The 2 tests are corroborated. Leica writes : " The overall performance measures up to the legendary LEICA APO-MACRO-ELMARIT-R f/2.8/100 mm from the LEICA R system." It's true. But not at full aperture for the 90. I keep my elmarit 90...