[ATM] Intro and slitless tester question

[bobmay at nethere.com (Bob May)]

At F25 you will be quite good to find the true COC within a few thousandths
of an inch.
Making a mask with a center hole and edge holes will allow for a little bit
better viewing of the shadows along with the addition of a small telescope
for enlarging the view as the mirror is so far away that it is almost a
single spot to your eye.  Just focus the telescope (a finder scope works
well) on the mirror and it will show the shadows very nicely.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net