Re: [ATM] Cassegrain vs. Gregorian (secondary testing) Best ofBothWorlds

[Kevin Whitefire <chaosopher23@yahoo.com>]

I checked the Gregorian aplanat version, too, but that
falls into the ellipsoid part of the curve.  It's a
bit undercorrected and won't work well with the cass
mirror.  The paraboloid will work all the way around,
and if I ever get ambitious enough, I will create a
lens setup that will correct the coma and astig for
both of them.  I think OSLO will do that, but I'm sure
I need more than the EDU version.

When I have the bugs polished out, I will post my new
version of CASSCALC, which will calculate an aplanat
instead of a cass.  The math is right, the flow is
wrong.

Kevin
--- Bob May <bobmay@nethere.com> wrote:

> Interesting thing about the Newt/Cass setup is that
> you can setup the
> primary for the R/C Cass with a primary of slightly
> overcorrected (I usually
> see numbers in the -1.05 or so) surface and this is
> perfect for the Cass
> while fairly good for the Newt.  The end result of
> the difference between
> the two is really quite small and still within a
> 1/10th wave error on the
> wavefront of the scope from a quick check with TEX
> for the change in
> numbers.
> Bob May
> http://nav.to/bobmay
> bobmay@nethere.com
> NEW! http://bobmay.astronomy.net
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 



		
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