I'm getting coloured blotchiness in the background of my subs. I've attached a screen snapshot of four sequential 60-second subs, taken with my ASI1600MC-C Pro at gain 75, offset 12 at a camera temperature of zero. The sub order goes top-left, top-right, bottom-left, bottom-right.
I thought it could be condensation but I had recently cleaned my lenses and camera window and had dew busters running - also, the pattern of the blotchiness changes from minute to minute which I think would be unlikely if it was condensation.
I wasn't dithering, and in the also attached integrated image (made from about 300 subs) I can see signs of correlated noise but the blotchiness appears to be a separate defect.
The minute by minute variation in blotchiness suggests that it may be a camera issue - does anyone have any ideas what it might be?
