Re: Coatings on Early M Lenses

["C.M. Fortunko" <fortunko@boulder.nist.gov>]

Marc,

Before running the camera department at Jones Drug and Camera, my friend was
the sales manager at Mike's Camera in Boulder. He really knows his Leicas
and photography too. Bob Adams, of Longmont, is a good friend of Benjamin's.
I think that this is enough of a recommendation. John van Stelten also
thinks very highly of him. Boulder is not New York and opportunities are
very limited.

My other friend is a dean of a university in Asia Minor. He did not work
directly on optical lenses, but spent approximately a year at Wetzlar
consulting on a new type of microscope. He and I have studied at Stanford in
the early 70s and have both worked on state-of the-art vacuum coating
machines while there.

Best regards,

Chris


At 12:24 PM 8/3/96 -0400, you wrote:
>At 10:38 PM 8/2/96 -0600, Chris Fortunko wrote:
>
>>I will second this. Van Stelten is local and a hell of a nice and competent
>>guy. I don't think he does this in his shop in Louisville, since I did not
>>see any equipment there. However, the work gets done correctly. I know this
>>on "good authority."
>
>REPLY:  John has the work done by a scientific laboratory nearby.
>
>>
>>I did not know about the drip process. However, a friend of mine who worked
>>at Leitz in the 1980s, did not think that Leitz coatings were state of the
>>art at that time.
>
>REPLY:  Leitz coatings have ALWAYS been "state of the art" insofar as
>patents allowed them to be.  I would like to know on what basis your friend
>makes this judgement -- did he ever work at, say, Zeiss or Rollei or Kodak
>or Wollensak?  He might well know what he's talking about, or he might not,
>but I think we're entitled to a precis of his credentials.
>
>
>>I have a DR Summicron with a superb coating. Could it have been redone? My
>>DR looks very good and much different from the other Summicrons (Rigid, DR,
>>and collapsible) I have seen. Many of them seem to have a shiny quality,
>>which a sales person in Palo Alto attributed to incorrect cleaning.
>
>REPLY:  The NF/DR Summicron dates from 1956 to 1968;  Leitz was using
>vacuum-coating techniques by 1960 or thereabouts.  Perhaps your NF/DR lens
>is post-1960 and your other two lenses are pre-1960.  As the drip coatings
>were moist and soft, they were much more susceptible to abrasion in cleaning
>than are later coatings.
>
>>A friend of mine (Robert Benjamin) in Boulder, and a Leica expert (now at
>>Jones Drug at Camera),  attributes the bad condition of some of the older
>>lenses to overuse of Kodak lens cleaner. He does not recommend the use of
>>this particular concoction at all. According to him, RoR should be used at
>>most once a year.
>
>REPLY:  Sounds like a great case of more speech than thought.  Maybe we
>should stick to what Leitz/Leica recommend and not to what some guy who
>works at a Drug Store claims.
>
>Leica has traditionally recommended the use of lens tissues and cleaner,
>whether Kodak or not.  They now recommend the use of micro-fibre cleaning
>cloths.  Lenses should be cleaned only when they need it, whether this be
>once a week or once a decade.
>
>Marc
>
>
>msmall@roanoke.infi.net  FAX:  +540/343-7315
>Cha robh bas fir gun ghras fir!
>
>
>