Archived posting to the Leica Users Group, 2004/11/07
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Sander, I did check whether this new batch of titanium stuff was still a coating or not. It states explicitly on the Leica website that the limited edition is made with solid titanium not a coating. I had not read that the Asph surfaces are no longer pressed. I know the asph surfaces for the f1.2 Noctilux and original 35mm f1.4 Aspherical (which is my most used lens BTW) were ground and the scrap was rate high. I know that the immediately subsequent asph surfaces were hot pressed. I had heard that there were problems pressing the asph surface for the 90 AA, but had not heard they had reverted to a ground surface. I had not heardl that any recent lenses were ground aspherics. The "mass" production of ground aspherics is certainly feasible now as they are used on the larger elements in Canon aspheric lenses, but AFAIK grinding is only used when the element is too big for hot pressing. I believe that the 35-70 f2.8 was dropped because it proved uneconomic to make to the desired tolerances, was this a problem with aspheric surfaces? Frank On 7 Nov, 2004, at 09:10, Sander van Hulsenbeek wrote: > Frank wrote: >> If the holdup is due to supplying titanium lenses I can guess the >> reason. Whilst there are good techniques for machining titanium >> nowadays if they only have experience machining aluminum and brass >> they may have serious problems getting a reasonable surface finish on >> milled parts even with the latest cutters. > > > The titanium is only a finish. On brass or alu lens parts. > So no machining of titanium required! > > And as far as I understand the lens parts come from > the factory in Portugal. That is not where the hold up is. > > The limiting factor is in the painstakingly slow, > one-per-very-expensive-machine, process of creating > the required aspheric surfaces - one per Summilux . And each ASPH > surface, after each round of milling or polishing, is checked by hand. > As far as I understand the 'hot-stamping' method is no longer used, > anyhow not for the Summilux parts. > > So once a priority order for 50 special lenses comes in, stop goes the > manufacturing for the normal > production. The factory in Solms is really small. Interesting, but > small! > > Sander > Amsterdam > Holland > > > > > > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >