Re: ATM Re: Unobstructed Newtonians

[Anthony Stillman <atmer@flash.net>]

Clive Milne wrote:
>   This really puts it into perspective....
>
>http://aberrator.astronomy.net/html/obstructed_planet.html


A terse examination of the images might lead one to conclude that
obstructions aren't so bad after all.  And actually, I agree.  However,
this level of image degradation is also consistent with the difference in
view from well figured and tolerably figured optics.

The added effort in un-obstructing a reflector, at least in the simplest
case, I would say, is on the order of doing a really good job figuring.
There are of course other trade offs and metrics.  Like f/ratio and the
cool factor.  So, is an 8" f/30 Schiefspiegler, with its 10 foot OTA, worth
making?  Well duh.

Anthony