There is another issue with rotation of camera. At least with my focuser the camera can stay with different inclination. What this cause ? Distortion of field.
I had problem with it. When the left side of the photos where well aligned, the right side isn't. And vice-versa. Normally at the periphery.
Stacking all photos in DSS or merging multiple results from stacking different groups of photos, the result was the same: I needed crop the image to eliminate the side with misalignment.
As I said, today I have the telescope and camera assembled full time. This and those prior problems are off. I must return to try multiple nights and ... why not ? ... mosaics, again !
