Archived posting to the Leica Users Group, 1997/03/27

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: Fogging
From: Jack Campin <>
Date: Thu, 27 Mar 1997 18:39:23 +0000 (Thomas P Myro) wrote:
: By saying that the Leitz lenses have a propensity for fogging, you are
: asking us to believe that some surfaces of identical composition could
: attract pollutants in greater volumes than others of the same compostion.
: Flourite is Flourite, and static charges aside,  I can't see why some
: flourite-coated surfaces could attract more pollutants than others.

Marc James Small <> wrote:
> I have never noted a preponderance of fogged glass in Leica lenses.  Leica
> lenses, in my experience, are far cleaner than are other makes of the era,
> especially the Japanese lenses, as they did not, and still do not, enjoy a
> quality supply of optical glass in that country.

The original poster was not talking about the glass itself or its surfaces
as a problem, but about volatile lubricants that Leitz used in their mounts
that other manufacturers didn't.

I find Marc's comment about Japanese glass incomprehensible.  Hoya is the
biggest optical glass manufacturer in the world.  The materials are all
either available anywhere (silica) or low-volume stuff any country can
buy on the open market (boron, rare earth elements); the rest is just
chemical processing, refining and melting.  Why on earth should there
be any national differences in this?

Thomas: it's   f  -  l  -  u  -  o  -  r  -  i  -  t  -  e .

- ----------------------------------------------------------------------------
Jack Campin   2 Haddington Place, Edinburgh EH7 4AE, Scotland  0131 556 5272 - for resources on food allergy
   & intolerance; McCarrison Society pages; freeware logic fonts for the Mac