Star Test results?

Post Reply
Posts: 38
Joined: Sun Aug 25, 2019 11:19 am
Location: Lacombe, LA

Star Test results?

Post by Jbest » Sat Jun 06, 2020 10:35 am

I posted another thread looking for an autocollimator but will set that aside and start this discussion.

The attached star test image is from my astrograph Newtonian 208/812 (8") · f/3.9

I recently bought a Farpoint laser & Cheshire EP which gave me a lot better results than my less expensive tools. I have a CatsEye autocollimator EP on order for the final solution.

Opinions on what you see here?

I think it looks pretty good, round & concentric, maybe just a hint of ovality that the autocollimator should help me adjust out. With my comma corrector removed I had to push the focuser tube all the way in to get this out of focus view. One of the flats on the OD is obviously from the focuser tube. Maybe the other is from one of the primary mirror's retention clips. I plan to either make a mask or shorten the clips from advice I've gotten on Cloudy Nights.

Jeff Best
PAS Secretary

Post Reply