cheers shiraz!
my alignment was hm ... quick and dirty? - so I had to make do with 15 seconds ISO1600. 20 seconds were already streaky.
the small tracking errors causing the wobble - like mechanical stops or something? uuuaaaahhhh!
No, no, I don't think that was the cause. On all images the stars all have 1 jitter in them. You know. Like as if you had touched the camera slightly. Such a regular mechanical error would be weird. You'd say so too would you see the jitter. I feel it's the shutter clicking while the camera is in that kind of floating rubber band mount.
Yeah, "coma" - that's the word.
No, I won't be "using" your DIY tool for real collimation. But it definitely showed me that the mirrors are completely off
Come on, let's have a beer or some other fizzy drink!