Vs: Vs: Vs: [Leica] M-multicoating, Summilux 35

["Raimo Korhonen" <raimo.korhonen@pp2.inet.fi>]

Because the idea of multicoating is about 100 years old, I have used the word "productionized" the whole time in this discussion - and in the earlier one, too.
In his LHSA magazine Viewfinder article the noted expert Dick Gilcreast writes that "at approximately No. 2,930,000 the 35mm Summilux received multicoating" - this would indicate end of 1978. Summilux 35 is a Walter Mandler design from 1961 so if the information that Leitz begun to use multicoating in 1957 was correct it would be logical to assume that all Summiluxes were multicoated - but it looks that they are not. If the Summilux 35 was designed for multicoating from the beginning, why did they not use it?
It seems to me that many Leica fans are eager to succumb to improbable stories created by some marketing people - of whom the former Leitz PR chief Gunter Osterloh comes to mind instantly. To me these only highlight the fact that Leitz never was in the forefront of coatings - not single, not multiple. Or maybe it is just me being too suspicious and cynical?
All the best!
Raimo
photos at http://personal.inet.fi/private/raimo.korhonen

- -----Alkuperäinen viesti-----
Lähettäjä: Henning J. Wulff <henningw@archiphoto.com>
Vastaanottaja: leica-users@mejac.palo-alto.ca.us <leica-users@mejac.palo-alto.ca.us>
Päivä: 19. elokuuta 2000 6:15
Aihe: Re: Vs: Vs: [Leica] M-multicoating, was: Rokkor story

>At 11:00 PM +0200 8/18/00, Raimo Korhonen wrote:
>>I do not doubt it - but my Summilux 35 from 1976 does not have
>>multicoating - so what was multicoated in 1957?
>>The Pentax multicoating has 7 layers and Fuji EBC has 11 layers so there
>>is a difference. And I "believe" that Optical Coating Laboratory Inc. was
>>needed to make multicoating commercially viable and they had some
>>important patents.
>>All the best!
>>Raimo
>
>Have you had it tested? If you do, I think you would discover that some
>coatings are multi-layer. All 35 Summiluxes have had this.
>
>At what point do you consider multi-layer coating to be "multi-coating"?
>Pentax seemed to feel that for PR purposes, their 7 layers qualified. As
>Erwin has stated quite correctly, multi-coating is something that has to be
>done in conjunction with the lens design, and is not something that
>necessarily provides the same benefits with all glasses and designs.
>Whether a lens has 7, 11, 3 or whatever layers should be determined by the
>overall design, not PR pressures.
>
>When Nikon started using multi-layer coatings around 1970, they tried to
>stress that some lens surfaces benefited from multi-layer coatings, some
>did not, and named their system Nikon Integrated Coatings (NIC) to point
>this fact out. That design concept has not changed with most of the
>manufacturers, including Zeiss and Leica.
>
>Optical Coating Laboratory, which I believe was a division of Raytheon, did
>have some patents on some coating technologies which Pentax and various
>other manufacturers used, but you have to understand that coating
>technology, and the transition to multi-layer coatings was not a one-time
>step, but a developmental process. As such changes in techniques and new
>insights lead to continual improvements on a regular basis, even now, and
>saying that Optical Coating Laboratory has some patents means something,
>but certainly not everything. There was definitely research and material
>advances in this area in the 50's already. The principles of multi-coating
>were known a long time ago.
>
>I did some work in optics in the 60's, and also worked for a while at
>Siemens in a physics lab where, among other things, I studied vacuum
>deposition production techniques. Multi-layer coatings were part of this,
>and it was no secret.
>
>Leitz's 1950's multi-layer coating techniques may not have been as
>sophisticated as the systems that Pentax and Optical Coating Laboratory had
>later, but that does not mean they did not exist.
>
>
>
>   *            Henning J. Wulff
>  /|\      Wulff Photography & Design
> /###\   mailto:henningw@archiphoto.com
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>