Thanks a lot Vicent!
So I use the overscan/prescan portion of the image closest to the target quadrant. Good! But what exactly does the overscan do? I can see no visuall difference whatsoever on the resulting image and from reading the processing console I can't see it has actually done anything as the ko scaling is 1.000 in all four target quadrants. I was imagining something resembeling the adjustments I've done manually with the script Juan wrote for your processing of NGC7331...
Best regards,
Ginge
