Rotation of stacked images across sessions

Above is the result of stacking images across 5 separate sessions. All taken by an unskilled beginner, so I am not surprised that the framing differs some across nights. The obvious answer is to remove sessions until I’m left with just ones where the framing is similar enough that the end result can be cropped without chopping off Central America :slight_smile:

Presumably there is information in what would be the upper-right corner, but that is lost from the resulting fits image. I am curious if it is possible to control why/how Siril decides to rotate the images so that I could combine all 5 sessions.

If the solution is only to be more careful about framing in the first place - that’s an acceptable answer, too.

Hi, there is a reference image in a sequence against all others are aligned. You can set it from the image list that is displayed from the button in the sequence tab.

Oh - thanks!

You can rotate the image after the stack too.
Processing menu->geometry

Excellent - thanks again.

Can the reference image be specified when using sirilic?

Not sure it is using the command setref. Maybe the dev version I don’t know.

For anyone reading this later - it appears sirilic orders and processes the sessions alphabetically, so changing the session name changes the reference frame.