Re: ATM 2nd post - first scope : )

["Bob May" <bobmay@nethere.com>]

When you use a mirror offaxis you have to consider that you are getting the
abberations of a mirror with the radius of the takeoff/EP axial point to the
outer edge of the mirror (I.E. a design with the EP sitting 2" from the edge
of the 4" mirror will be acting like a 12" diameter mirror of that Focal
Length) so be aware of the problems that you will be having.
For example, I have built a 42' (yep!) FL and when looking at the sun and
reflecting that to a horizontal direction, the difference in focus between
sag and tan for focus is about 6'!
Bob May
http://nav.to/bobmay
bobmay@nethere.com