mommoteandcoyote wrote: > Rick, > > The only real problem I found with the system , was the increased coma due > to the extreme shifting of the corrector from its optically pure position at > the radius of curvature of the primary mirror. > If I understand the stuff that comes out of ZEMAX here, it looks about equivalent to an f/8 (or slower) Newtonian. Rick S. > > Coyoté