Archived posting to the Leica Users Group, 2005/01/25
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]This reminds me of arguments we used to have when I first got into cars. Cars with plastic were no good, and cars which were all metal, dashboard including, were best. I'm nearing 300,000 miles in my plastic Volvo. In the old days, the best I could do with an all metal beast was 50-85,000 miles. S. Dimitrov On Jan 25, 2005, at 9:03 PM, John Collier wrote: > In the old days it was impossible to make precise enough lens mounts. > Every element had to be hand fitted, shimmed and centered. Glue would > be a foolish attachment method as the likelihood of making mistakes > was very high. In short there was a good chance you might have to take > it back apart to get it right. > > Now machining precision is phenomenally accurate. This eliminates the > costly hand fitting. If you compare the lens schematics of the old and > new 50/1.4s (non-Asph) you will see what I mean. Same formulation but > the newer glass has precision mounting surfaces. > > This means that we get smaller sample variation and generally better > overall performance as the manufactured lens is much closer to the > ideal. > > I do not mind that my lenses have to be heated to be disassembled. I > am just so d***ed impressed with their performance I don't care! > > John Collier > (who has on occasion lost in the sample variation game with older > lenses) > > On 25-Jan-05, at 12:20 PM, Didier Ludwig wrote: > >> Slobodan's concern is justified, IMO. As it was presumably me >> starting the thread about glued lenses and heating them, I can only >> repeat what the Leica specialist from Karl Ziegler Fototechnik, a >> reputed camera and lens repair company near Zurich, told me: Most, if >> not all, of the newly designed Leica lenses have more or less glued >> parts or blocks inside. It allows smaller and lighter constructions >> and lowers the engineering and production costs significantly; but >> raises the repair costs on the other side. This is, economically >> seen, good for Leica, but bad for us as soon as we have a lens to >> repair. ALL new japanese lenses were made like that, too, he said, >> manual and AF. It's just the way how lenses are manufactured these >> days, whether in Europe or in Japan. >> >> Thats why I'd say, don't trade in your old pre-ASPH's for the new >> ones, as they might survive them :-) >> Didier > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information > > Slobodan Dimitrov Photography