RE: [Leica] Fogging

["Greg.Chappell@nationsbank.com" <Greg.Chappell@bankofamerica.com>]

Same here. I recently purchase a 50 3.5 Elmar that dates from 1939. It was
converted at some point to Red Scale and was coated, I guess at the same
time. I sent it to Sherry & it came back smooth as silk and clean as a
whistle inside. You'd never know from looking at it that it was 60 years
old! The B&W picas I took with it BEFORE it went to her were impressive to
me. Can't wait to develop the first roll, which I'm currently working on,
since I've received it back.

Greg Chapel

- -----Original Message-----
From: dwpost@email.msn.com [mailto:dwpost@email.msn.com]
Sent: Monday, August 09, 1999 10:42 AM
To: leica-users@mejac.palo-alto.ca.us
Subject: Re: [Leica] Fogging


Karim-
I found a really nice Summaron 35 LTM lens. Cosmetically, almost mint, and
really a nice compact lens- and fairly sharp. It too had 'fogging', as do
many, many lenses from the 50's when they used a lubricant similar to
Nyloil- the watch and clock lubricant made from whale oil.
Unlike petroleum greases that are composed of hyrocarbons of various
molecular length, and different evaporation rates- and which tend to harden
of a few years time, the whale oil lubricants were composed of molecules
that are of a fairly consistant weight, complex esters that tended not to
'dry' or harden, so the life of the lubricant was much longer, and more
stable at different temperature extremes.
They have a tendency, over time, to migrant, sublimate, and like the greasy
film on your kitchen walls, from cooking, these oils, after 40-50 years,
tended to get on the glass.
My personal experience is that this oil, and sometimes edge separation is a
bigger problem by far than 'fungus', even in the south whare I live. The
upside is that the oil can be cleaned off, relatively cheaply, and the
separation can be repaired (not so cheaply, but can be repaired). In fact, I
have bargained the price down on a lens by $150 or so, knowing that for
$75-85, Sherry could set it right!
You will be surprised what a difference a good cleaning will make! My lenses
usually gain at least one stop of contrast, and the sharpness improves
noticably as well.
Dan

- ----- Original Message -----
From: Karim H. Karmali <kkarmali@home.com>
To: <leica-users@mejac.palo-alto.ca.us>
Sent: Sunday, August 08, 1999 12:11 PM
Subject: [Leica] Fogging


> Is there any way of telling whether the fogging you find in some older
> lenses can be removed or not.  I recently purchased a very clean example
of
> an older Summaron 35/3.5 for my M3.  Unfortunately, both the spectacle
> viewfinder attachment and lens appear to suffer from some fogging.
>
> Thanks for your thoughts.
>
> Karim
>
>
>