Re: ATM Corrected Cassegrainian

[Andy Saulietis <iss@pvtnetworks.net>]

Re spherical primary correction,

>You should be able to do a decent correction for a spherical mirror with a
>corrector.  Some of the little 4..5" scopes use a spherical mirror and a
>corrector in the focuser tube.

I recall that Buchroader did a couple of large cassegrain
type scopes which had all-spherical optics..these had several
correcting lenses in front of the focal plane. There was also
a meniscus lens corrector design in S+T several years ago that
was sub aperture & was placed just ahead of the sec mirror..
still not a trivial project in a 40" as the lenses would be ~>10" dia.
I looked at reflective correctors also..can't be done with just
one surface.




Andy Saulietis
ISS Enterprises
10 Milky Way
PO Box 19
Mayhill NM 88339


World's first astronomy land development:

http://www.pvtnetworks.net/~iss/starend1.htm

8 of 17 lots sold to astronomers as of 10/03

505-687-3067 voice/fax, call voice or e-mail to set up
e-mail: iss@pvtnetworks.net