ATM Collimnating a Newtonian with central perforation.

[Nick Martin <bonnyton@ednet.co.uk>]

Many thanks for all those replies. There is a lot of food for thought.
I will post how I get on at our next observing session with the scope.
My next problem is diplomatic. Persuading the owner to let us cut back a pet
maple tree which grows next to the dome conveniently obscuring the southwest
and western sky.
Nick 
Nick Martin, Bonnyton House, By Ayr, Ayrshire KA6 7EW ,Scotland, UK.
 Latitude 55 24'56" Longtitude 4 26' 00".
"Eppur si muove" Galileo Galilei