[alpal]

Originally Posted by OzEclipse

Check out the Newton Corrector on Philipp Keller's site
http://www.astrooptik.com/

I believe this corrector or something very similar is used for the Boren Simon Powernewt scopes.

http://www.teleskop-service.de/astro...astrofotos.htm

Joe

Thanks Joe,
none of those correctors are recommended for f3.
I think they would all give eggy stars at the corners.

cheers
Allan