On Thursday, September 20, 2001 at 12:39, clintonr@xxxxxxxxxxxxxxxx
<olympus@xxxxxxxxxxxxxxx>
wrote on "Re: [OM] window cleaning," saying..
> It's my understanding (subject to those who may know better) is that
> "multi-coating" is done by super-heating lens elements in a vacuum,
> then injecting vaporized rare earths into the chamber. The surfaces
> of the "glass" are thereby impregnated with a very thin layer, usually
> 1/4 of the wavelength of the particular spectrum of light being
> compensated for. And I don't believe the interior surfaces are
> "coated" at all (again, there may be those who know better....), and
> it's the interior surfaces that usually grow fungus.
The interior surfaces are the most important to coat, since
reflections from them get to the film (glare), while reflections from
the front element just go into the ether.
Tom
--------------- Abacurial Information Management Consultants
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