Diagnostic help please

Helen · July 28, 2011

I've been trying to get my hyperstar set up working over the last couple of clear nights. I was using CCD inspector to set the collimation, got it down to a small error, and so thought I should have been OK. But I got some very odd star shapes (see below). I tried both manual focussing and focusmax. I've been working on it again tonight, but as its cloudy, I've been using the artificial star (thanks MikeP :eek: ). Again centre of field numbers are down below 2, but when I move the star to the corners the star shape goes very unbalanced (I haven't got enough focus travel to get the artificial star into focus to see what that looks like). I've posted the 5 star shapes below too. (The blank gap is the cables from the camera crossing the primary mirror.)

I'm thinking that not only do I need to know what is wrong at the moment, but it it would be REALLY helpful to have advice on a process for solving this sort of problem in the future. So would people mind talking me through the investigative process please

What are the signs of differing problems? how can I test and rule in or out potential problems?

I'm hoping other people will find this useful too

Many thanks

Helen

Edit: files didn't upload properly, trying again...