ATM Optical Windows for CCDs

[lynchkj@erols.com (Kenn Lynch)]

I recently posted this msg in the CCD list . but I thought maybe some
of my more "hands on and eye for a bargain" ATM aquaintences (SIC?)
might do better at the materials location questions. <G> 

Hello
I am wondering if anyone can recommend a source for the
Optical window for use in the Audine camera, (50x 3mm )
(or general info
http://astrosurf.org/terre/audine/index0.htm (French only)

The site is in French only at present, but it's a CCD construction
site, it's KaF0400 based and Air cooled and appears to require only
relatively simple machining!.   Take a look!


and now back to the Optical window question <G>
Anyone have experiences as to the pro's cons
of coated vs uncoated glass? or care to comment the impact 
of the quality of the window this close to the CCD's surface.
(around 5 mm from the FP)

How about using a skylight filter or "plain glass" Photographic
filter?

Edmund's  sells a (thinner) 50 x 1.5mm uncoated optical window that is

"relatively parallel" (their words) for $4.50 (V53-124) 
maybe they may have better, in their  "professional" catalog?

UO sells their Optical window for the CBC for $17.95
size, I guess is the 1" specified in the CBC drawings 
no mention of coatings or quality? (seems a bit steep? <G>) 

I've even seen the coated windows from the 
4.25" Astroscan's available for $10, 
anyone know away to cut small circle in glass
Other than the slurry ring method <g> 

I know someone out there must have used an alternative
to the UO unit?
The 50mm size is not absolute but I'd like to stick to plan
if possible (makes machine the "T" adapter easier )

Thanks for your time
Kenn Lynch