[alistairsam]

Hi Steve,

Its possible the collimation was off, I took this defocused star image during the run. shows the secondary is not exactly centred.
I did collimate with a cheshire and a cats eye 2 pupil AC when the ota was not on the mount.
I then checked with just the laser when it was on the mount.
But I noticed very eggy stars while focusing, so thought the locking bolts for the cell maybe too tight, I loosened them, not too much of a difference.

if its collimation, will the elongation follow the camera when rotated, cause mine did. I rotated and the elongation rotated as well.
I then loosened the focuser lock screw as that was tilting the camera quite a bit and used rubber bands to keep the camera flush against the lip of the drawtube and then took the 47tuc images.

I'll centre the secondary again and do some more tests cause I'm not getting round stars in the centre even for 1s exposures.

Thanks
Edit: added an overlay image with the error. wonder if this is sufficient to show elongated stars in one side.