Re: ATM Again:Dall-Kirkham and coma correctors...

[MitchAlsup@aol.com]

In a message dated 98-11-08 18:39:36 EST, you write:

<< atm@shore.net >>
Kevin McCarthy wrote :

> The Paracorr is optimized for an f/4 cone, and works badly with f/8 or
> f/16 designs. 

Based on a paper by Al Nagler dated 7/89 on Paracorr Evaluation;

This paper has a diagram of the Geometric spot size versus semi-field
for Parabolic mirrors. This paper indicated that a Paracorr changes
the ComaFreeField of an F/8 parabloid from 7.5mm Semi-field to
larger than 25 mm. It makes the entire field coma free. So much for
not working at F/8. The residual errors after the paracorr is less than 
1/2 the size of the airy disk over the entire semi-field (20mm) plotted.

Mitch