Re: ATM Ronchi offset

["John D. Upton" <upton@austin.ibm.com>]

Walter,

At 04:35 AM 8/30/01 -0700, you wrote:
>question is about the "offset", how do I make sure I
>start in the right place?  Moving the mirror forward

     The grating offsets are measured with respect to the radius of 
curvature of the central zone on the mirror -- i.e. the paraxial ROC.  A 
similar question about how to find that point came up on the list a short 
time ago.

     Rather than repeating the answer, I would refer you to the ATM List 
archives.  My method of finding the ROC starting point for Ronchi Testing 
can be found at 
<http://astro.umsystem.edu/atm/ARCHIVES/JUL01/msg00131.html> in the 
archives.  Read the other responses in that thread for other ways to do it 
also.

Sincerely,

John D. Upton
Georgetown, TX
<http://www.atm-workshop.com/>      "The ATM's Workshop Page"
<http://members.aol.com/RonWin20/>  "Ronchi For Windows Software Page"