Hello!
I'm new to astrophotography and PixInSight and so far I'm learning quite quick how to use this program. Now everything went good so far on my image but there is that weird horizontal blue / green and sometimes red background color cast over the whole image. I checked the CR2 raw image directly from my Full spectrum modded Canon 600D and the artifact is there too, so it's not an issue with DSS stacking or any of the calibration files, and it's the issue with the camera itself (the artifact is on every single image I've taken with this camera this autumn / winter.
Here is how it looks like: (i'ts a cropped preview image)
Which tool do I need to use to average out the RED, GREEN and BLUE color values in my background without effecting the midtones or highlights (maybe a mask will help with that).?
Clear skies!