Quote:
Originally Posted by Sunfish
Look on the Stellafane website in the testing section for a video lecture regarding auto collimation testing. The mirror is required to be optically flat first surface . The video describes the specification of flatness required and the history and design of these kinds of testing rigs.
|
Thank you for the link. I did have a look at the auto collimation test setup and will build one as soon as I can get hold of a reasonably priced 300mm flat mirror, or 300mm blanks.
Sydney glass quoted me $319.00 for one 25mm blank, and $154.00 for polishing.
Telescopes and Astronomy sells 305mm x 25mm for $162.00. Need three blanks.
My concern is the thickness. It should be OK for a flat mirror, but I would eventually want to use the remaining flats to make a mirror 300mm and it might be too thin.
One guy tried to laminate, but said he was not successful with epoxy. Have to look him up and see what went wrong.
I am looking around on AliBaba and will get some answers maybe on monday.
Where else could I look?