|
that is starting to look really promising Russ.
You know this stuff, but FWIW, the various faults might possibly be:
1. field rotation - see if the star elongation changes with exposure length.
2. collimation - did you collimate through the CC? - minor tilt in the CC elements can throw everything off and I found that collimating through the CC was essential.
3. image plane tilt - anything other than screw thread or flange extensions will be too sloppy to keep stuff aligned. If the image train is rigid and there is still some tilt, I think that the camera has a tilt adjustment ring? the SX website has a great procedure for adjusting CCD tilt using laser projection if you need to adjust the camera - should work fine with a QHY
4. flex - if that is one of the GSO steel tube scopes, it would be a good idea to reinforce it around the focuser.
5. CC spacing - has to be exact including any filters - there is nowhere for minor aberration to hide with small pixels
not seen anything like the row fault in the 2x2 image - could it be a jpeg compression artefact maybe. Maybe ask Theo for an opinion, but I would sort out the other stuff before worrying about that issue. Otherwise, the chip looks very clean.
|