Archived posting to the Leica Users Group, 2008/11/21

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Subject: [Leica] Multi-Coating Development
From: marcsmall at comcast.net (Marc James Small)
Date: Fri Nov 21 20:06:17 2008
References: <25182388.1227320210018.JavaMail.root@elwamui-royal.atl.sa.earthlink.net>

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!



Replies: Reply from robertmeier at usjet.net (Robert Meier) ([Leica] Multi-Coating Development)
In reply to: Message from wildlightphoto at earthlink.net (wildlightphoto@earthlink.net) ([Leica] Are Leica lenses muliticoated?)