Re: [ATM] Maksutof corrector minimum thickness

[Dominic-Luc Webb <dlwebb@canit.se>]

On Fri, 12 Nov 2004, Ken Hunter wrote:

> Here's an exercise for the MATH whizzes on the atm
> list...
>
> If I have a Fused Quartz blank 20 inches diameter and
> 2.375 thick, can it be generated into a corrector for
> a 20 inch Maksutov?

Sorry about the delay. No, Mak is not a realistic option. Using two
correctors sounds like the collimation from hell.

Maybe a corrector for Schmidt? There is a fare amount of variety in
thickness and curvature in a Schmidt corrector dictated by overall
system geometry. The refractive index comes into play also, but as
I recall, it did not make a huge difference. However, I think the
diameter relative the primary and system focal length mattered a
great deal. Reference 6 on my 310 mm Schmidt page has free (use at own
risk) C source code I wrote to calculate the polynomials you could enter
into  OsloLT, etc. Maybe that would help speed things along? Code was
written with Unix in mind (GCC), but it is very simple with minimal
dependencies on include files, libraries, etc. I am quite sure someone
successfully compiled it under Windows a while back, but I do not have a
Windows compiler myself.

Here is the direct link...

http://www.megspace.com/science/stp/catadioptric/310schmidt/310schmidt.html


That being said, there are exponentially fewer and fewer of these
catadiotric systems anywhere on our planet when you get into these
large apertures. Pretty much all the commercially produced and pro
Maks on our planet are 18" or less. The case is similar for the
Schmidt. A successful 20" Schmidt corrector at any thickness produced
by any ATM would impress the mess out of me.


Dominic-Luc Webb

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