Re: ATM 16" F/33 valid design?

["Frank Ward" <thewards@mindspring.com>]

Joe, You ask

>See with that say 10" f-6 primary,  how "Fast"
>you could make it with simple "Edmund" Specials lenses used as the convex
>secondaries (spherical of course)  how fast (low of a f- ratio) can it go
before
>undesirable image degradation occurs.

The only problem I have with this idea is the fact that no telescope I know
of
uses a parabolic primary and a spherical secondary.  No matter what the
focal
length you won't get a focused image. I know I'm wrong in a lot of
conceptual
optics but thats pretty basic. Now, if you had a prolate ellipsoid
primary.......

Best wishes,

Frank Ward
Atlanta, GA