Re: ATM Dall Kirkham

["Bob May" <bobmay@nethere.com>]

Aside from the fact that I don't consider the Dall-Kirkham design really
worth building (this from a guy that built a single lens refractor!), the
parabola is just as hard to build as any other surface to put on a piece of
glass.   The only difference is knowing what the numbers are that you have
to use to get the Foucault test to test the surface properly.  Scraping
molecules off of the glass is still basically the same when it comes down to
the figuring.
Personally, I'd do the Dall-Kirkham just for the fun of it and then do the
other Cass designs as a backup so that you can have a set of scopes all in a
family of size so that all can see the differences in the quality of each
design.  Now go do it!
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net