Hi George, I sincerely wish I could engage in what I would consider an insightful conversation on the Merits (or lack thereof) of the themes and arguments Roger Cicalla presents in the two essays of his at the link I shared. The best I can do to argue them is say a) that Roger appears to have leveraged his comany's unique insights from having owned many multiple copies of a broad range of lenses whose 'designs' are considered High Performance Optics. And b) tied that argumentally well with theses regarding the confluence of challenges presented by the utterly flat plane of digitalimage sensors, those sensors having reached a combination of small enough pixel sites and/or pixel counts which make detecting quite minute variations in alignment of any optic used with them a straight forward proposition, and theoretical and ancedotal information regarding the cause of one customer exchanging a rented lens as unusably soft and the exact same copy of the lens being extolled by the next renter as being stunningly sharp. Please look to his essays for understanding and/or clarification. As far as how it relates to a discussion of the Zeiss Fifty f1.4, Roger directly discusses how a number of modern fast aperture lenses, especially when used in combination with high resolution sensors, are especially susceptable for tripping over the problems of manufacture variance that are central within his essays. (to paraphrase his writings). I believe he directly listed the Zeiss 85 f1.4 and the Canon 85 f1.2 L, but maybe others too. He also described how Mount Variances are affecting achieving peak performance with high quality wide angles. Sincerely & Respectfully, Richard in Michigan ____________________________________ Sent From An M8 User.... :-) ____________________________________ On Jun 6, 2011, at 4:23 PM, George Lottermoser <imagist3@xxxxxxx> wrote: > > On Jun 6, 2011, at 10:25 AM, Richard Ward wrote: > >> A key component for one of his arguments was manufacturing variability in >> both the mount on the lens and the mount on the body. > > I find this a bit odd. > If we're talking about SLR cameras. > > While the camera and lens mounts may affect the short or long (infinity) > focus ends > they sure should not affect - "focus" accuracy; > which is accomplished by a well aligned mirror and ground glass screen > in relationship to the film or sensor plane. > > Think of placing an extension tube or bellows between the body and lens > you should still be able to focus the lens accurately within the range > offered by the extension. > > Regards, > George Lottermoser > george@xxxxxxxxxxx > http://www.imagist.com > http://www.imagist.com/blog > http://www.linkedin.com/in/imagist > > > > > > ------ > Unsubscribe or change to/from Digest Mode at: > http://www.lrflex.furnfeather.net/ > Archives are at: > //www.freelists.org/archives/leicareflex/ ------ Unsubscribe or change to/from Digest Mode at: http://www.lrflex.furnfeather.net/ Archives are at: //www.freelists.org/archives/leicareflex/