Roddier Testing

[MarkS]

I don't know if I've mentioned this before - a piece of software on a French website for performing Roddier testing:
http://www.astrosurf.com/tests/roddier/projet.html

By taking extremely intra and extra defocused images and processing them in this software it will show inaccuracies in the optical system and other distortions such as pinching, astigmatism etc.

I used it very successfully on the C11 to prove just how good the optics were.  I intend to use it on the Tak for finely adjusting the "mirror pressure screws".

If you don't understand the French then I'm sure Google translator will come to your aid.