There were patches of blue sky this evening, but plenty of thin cloud too, Jupiter and Venus were visible before sunset though, so I decided to get the Mak outside cooling and hope we’d have enough clear sky to do a star test.
After dark I connected up the motor drives and moved the scope around to pick up Procyon. Defocusing the view in a 20mm eyepiece I saw what appeared to be a nice set of round, concentric diffraction rings. By eye, and without an artificial star, I think I’m unlikely to do any better.
I’ll see if I can get an image of the diffraction rings with a camera later.
Here’s an image taken with my SPC880 webcam. I think it shows that a little more tweaking vertically could be done, but otherwise I think it’s not bad.