Re: ATM [Fwd: BOUNCE atm@shore.net: Non-member submission from [btk@ix.netcom.com (Bill Marriott )]]

[goffaxe@azstarnet.com (Valerie & Bob Goff)]

Editing is so much fun. But, I'm glad that I'm an optician instead of a
journalist.

I'm afraid that the residual secondary spectrum of a maksutov corrector will
leave a bad taste in your mouth or is that a purple halo in your eye.
Why do you not invest your glass thickness in an equally good window that is
flat and has good transmitted wavefront. make your favorite aperture ratio
parabola and place a metallographic apochromatic microscop objective after
the foccs followed by a small diagonal prism and get an f/50 or 75 final
ratio? It's planetary after all. And the microscope objective won't mind
being just a little bit out of conjugate. Strip the objective down to its
underwear and mount it andthe diagonal on a stem from the middle of the window.
Window: two curves that have the same radius of curvature and can be tested
for parallism by means of Heidinger fringes. Easy.Only one set of tooling.
No secondary spectrum. Retention of achromatism. Very small central
obscuration (5%)
Try it. You'll like it. Mikey likes it.....
Bob