29 Oct
2013
29 Oct
'13
3:43 p.m.
A 70 inch with a 10 inch secondary in a Newtonian configuration would have to be of similar f-ratio, f/8-ish, or over 45 feet long with the eyepiece somewhere near 40 feet. Again, a too-tall ladder and probably unstable in any kind of breeze at all. On Tue, Oct 29, 2013 at 2:45 PM, Erik Hansen <erikhansen@thebluezone.net>wrote:
Or how about a 70 inch f4 with a 10 inch secondary.