Archived posting to the Leica Users Group, 1997/01/03
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 09:10 PM 02-01-97, Dennis wrote: [snip] > >>Well, I find it a bit interesting that Docter Optic Technologies, of >>Wetzlar, patents a blank-molding method for the mass production of >>aspheric lens elements, and that Leica, two or three years later, adopts >>a like method for the 1.4/35 ASPH lens. I suspect they licensed the >>technology, as the hand-production of elements was bound to be >>time-consuming and quite expensive. > >>Marc > >Anybody have any idea _how_ they do that? Mold lenses from glass that is. >How can they come out of a mold without needing any polishing, or do they? I am not sure if they do any polishing after the moulding process, but I have a related question. I can recall reading an article in Leica fotographie about the lens. Perhaps it was due to poor translating (from german), but I had the impression that Leica would produce the aspheric element, measure its optical parameters, then adjust the remaining elements so that the overall lens would be to spec. Thus each finished product could be first rate even if there was a large variance in the quality of the individual molded aspherical elements. Would anyone care to comment on this? If my reading of the article is correct, whatever you do, don't dissassemble your 35 aspheric! Dan C.