Archived posting to the Leica Users Group, 2005/01/26
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Feli, I think that if you shoot at full aperture where even a flawless, recently CLA'd DR can produce some flare, you can find a bit of "glow". Seth ----- Original Message ----- From: "Feli" <feli2@earthlink.net> To: "Leica Users Group" <lug@leica-users.org> Sent: Wednesday, January 26, 2005 2:26 AM Subject: Re: [Leica] adhesives > > On Jan 25, 2005, at 10:33 PM, Frank Dernie wrote: >> Adhesives are widely used in almost every engineering discipline now. It >> is lighter and cheaper and plenty strong and accurate enough. I do not >> agree that the recent lenses are necessarily better than older because of >> modern machining though. They certainly no longer need massively skilled >> technicians to assemble them, but the old stuff, hand assembled, shimmed >> and carefully inspected during assembly should all be the same as each >> other within similar tolerances to recently lenses, it just takes more >> manual skill and time to achieve the same level of consistency. >> That is not to say the recent designs are not optically better, my 35 >> f1.4 aspherical is comfortably the best 35mm lens I have ever used, >> obvious even on the RD1, it is just that my experience of precision >> mechanics shows me that it is much cheaper and less skilled to reach the >> same level of precision nowadays than 30 years ago, but the final level >> of precision is no greater today than then. Materials, OTOH are hugely >> better today than then. >> Frank > > I wonder how much advances in the testing equipment used during assembly > affects the performance of vintage lenses. Anyone remember the spinning > drum with the slots cut in to it, that Leica used to use to test shutter > speeds...? > > I recently had my Summicron DR cleaned by Leica NJ. It's always been my > favorite and most used lens, > so I am very familiar with the results it produces. > > The good news is that there is a very visible jump in performance. It > always was a sharp lens, but this is ridiculous. > Contrast is also up by a noticeable margin. Both of these improvements are > even more visible when shooting wide open. > > The bad news is that when Leica cleaned out the haze, they also killed the > "glow", which I loved very much. 8-( > Sometimes it glowed a little too much. If a bright lightsource was in just > the correct spot, it would flare out the > entire frame. Seth told me that the white haze is actually oxidation > formed by the metal in the glass, as it is exposed > to the oxygen in the air. So, it appears that old lenses ripen with age, > like a good wine. ;-) > > feli > > ________________________________________________________ > feli2@earthlink.net 2 + 2 = 4 www.elanphotos.com > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >