Archived posting to the Leica Users Group, 2008/11/21
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 09:16 PM 11/21/2008, wildlightphoto@earthlink.net wrote: >Robert Meier wrote: > >>Zeiss is the one who developed their T* coating at the same time Pentax >>developed Super Multi-Coating (and maybe even in cooperation with them). > >I don't know about Zeiss, but Pentax didn't develop the Super >Multi-Coating process. It was developed by Optical Coating >Laboratories Inc. (OCLI), now a part of JDSU in Milpitas California. We have this conversation all the time and a run through the archives would be instructive. Here is a VERY short condensed history: Multi-coating was developed in theory in the late 1920's and as a one-off process in the 1950's. There were a number of firms working at that time to transform this into a commercially usable technology. I had not previously heard of OCLI but I would suppose that they were working under the direction of Asahi. In any event, the Zeiss Foundation was anxious to get out of the camera business and had a five-year relationship with Asahi from 1965 to 1970. During that time, Zeiss desveloped the K Mount and the two firms pooled their work on multi-coating. The deal finally fell through because Zeiss wanted the majority of lens production to be conducted in Japan, and Asahi felt that Japanese customers would want German-made Zeiss lenses. Asahi walked away with the K Mount and their SMC processi, while Zeiss got the same process, which they called T*. Zeiss introduced multi-coatings on some lab gear in early 1969 and Asahi first produced SMC lenses in, I believe, late 1969. Both Zeiss and Asahi released their patent rights for general use around 1975, and I suspect that that would have been when Leitz began multi-coating its lenses. Marc msmall@aya.yale.edu Cha robh b?s fir gun ghr?s fir!