On the first night under the stars, it only took about 45 minutes to tweak the
primary mirror a bit, and get round stars in all 4 corners of the image. This
was so much easier than my earlier experience! I suspect that on the first "round"
with this scope, the secondary started out of center, and there was no good way
for me to check or adjust it. This time, a turn of about 1/5 on one primary collimation
bolt, and a turn of less than 1/16 on another, eliminated nearly all of the corner
distortions.

This image is only a test image. It is the open cluster M 44, a stack of 6 x5 minute
exposures. This is encouraging, though it is too soon to be sure I won't find the same
problems with 'shifting' collimation that I found before. However, the stars looked equally
round even after rotating the focuser 180 degrees. Whatever was affecting the collimation
laser during rotation has no apparent effect on images.