Re: (ATM) off-axis paraboloid mirrors

Bratislav Curcic (epabcc@epa.ericsson.se)
Wed, 23 Aug 95 09:57:33 EST

An off axis parabola will have a bit less coma than a mirror twice as fast. In other words, an f/9 off axis mirror will have coma almost as much as a f/4.5 one.

Making GOOD off axis parabola is no easy task, though. I'd stick with ordinary f/6 to f/8 classic Newtonian; excellent optics, even reasonably obstructed (say 0.2) will outperform by a wide margin unobstructed, but otherwise mediocre one.

Bratislav