After taking some pics tonight I noticed during processing there was some blurring of the image, almost like ghosting. It may well be collimation - I didn't check before taking images (in a rush...), having done a daylight collimation yesterday.
I'll make sure I do a star test before the next session, but in the meantime I'm just wondering if this ghosting is a symptom of poor seeing? It's more noticeable in the Saturn pic...
Cheers
Stephen
Stephen it looks like some bad frames with poor seeing made it into in your final stack. You might have to remove them manually if your stacking program can't.