Re: Printing through flat glass

Jadlupp (Jadlupp@aol.com)
Tue, 07 Apr 1998 17:03:32 -0400 (EDT)

In a message dated 98-04-02 16:06:46 EST, jfaul@dn.net writes:

<<
Cyclamate wrote:
>
> Have any of you had any experience in obtaining "optical quality" glass for
> your print frames?

Yes!
There's a place in Florida -- I forget the name -- but I'll think about
it. I got a piece of 24x30 inch Anti Newton optically flat Glass for $75
plus shipping. >>

Be carefull here - "Optical Quality" and "Optically Flat" are not the same
thing. Generally, optically flat means the glass surfaces are parallel and
flat to within one or two light-bands of flatness over some arbitrary
distance, while optical quality has to do with the lack of imperfections when
looking through the glass. Most optical glass is also optically flat, but
optically flat glass can be translucent, depending on usage.

I have some optical quality glass, about four by six inches, that is a part of
my Illumitrans (Bowens Optical, England) slide copier, but it is too thin for
use as a glass in a printing frame.

Don