Re:ATM Cassegrain as second telescope project.

[Frank Henriquez <frank@ucla.edu>]

I've thought about trying a cass system, since my first abortive 
attempt decades ago. Back then, I tried making the secondary out of a 
lens that had the approximate RC required.

My biggest stumbling block was the thought of having to make one or 
more extra mirrors just to test the system.
One secondary testing "method" I though about using was not to test 
the secondary at all before use. Give the primary as good a 
paraboloid as you can achieve, then star test the secondary, until 
the system performance is good.

Another option would be to use the Dall method to test the secondary. 
It doesn't require making any extra test surfaces.

Frank
-- 
Frank Henriquez  Programmer/Analyst  Jules Stein Eye Institute, UCLA
frank@ucla.edu   http://www.bol.ucla.edu/~frank/index.htm