Re: [APML] Large Format Question

["Joseph O'Neil" <joneil@multiboard.com>]

>Not being a chemist or an optics guy, I don't really know why they
>elected to use thorium in the lens.

         During WW2 Kodak did a wide amount of experimentation with lenses, 
and I think, the first, wide spread use of optical coatings (not consumer 
optics, but some military optics), started to become a reality during WW2 
as well.
         Anyhow they experimented with all sorts of things, not just 
different glass types, but also even how the manufacture of glass itself 
took place.  The use of thorium is essentially a phase they went through 
while developing new lenses.
joe



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