Re: ATM Maksutov Correctors

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

Dominic, yes, you can use a mild planoconvex surface for the corrector
plate.  The first problem that you run into is that the color correction
won't be the optimum.  The placing of the ring at the 86% point produces a
spot where the color error is averaged over the center of the spot.  The
second problem is that the curve isn't a spherical curve but rather a more
complex curve and that will mean indeed that the spot size will increase as
you are just approximating the center of the Schmidt curve.  I haven't
looked at the curve that close but I'd suspect from just a moment's thinking
that the curve for that planoconvex lens would have to me more of a
hyperbolic surface.
Schmidt did use the vacuum pan method as in reports of how he did the curve
was that he used the properties of the glass bending and the only logical
method there is putting a vacuum on one side of the glass, especially
considering the properties that he used in the calculations.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net