Problems with meridian flip handling


Back with another issue.

I am processing multi-session files with a meridian flip in between.

  1. The preprocessing and merger is done in Sirilic
  2. The registration is done manually in Siril with the merged sequence generated by Sirilic
  3. The reference file is after the flip.

The registration runs fine, but the images from before the flip are angled as in the screenshot. All files after the flip (i.e., same set as the reference image) are okay.

Any suggestions?

Thank you.

Meridian flip is not the issue.
Meridian flip is just a 180 field rotation.

So if the new images have this rotation this is because something else did wrong in your night session. Especially if registration is fine.

The image above is not rotated, it is just cropped in that shape.

So 2 questions

  1. if it was a complete 180 rotation Siril would handle it?

  2. What if it was not a 180 rotation but say 100 degrees or something. Then could this happen?

No. It is rotated to match with the reference. This is cropped at the top and at the bottom to fit the size of reference image. No matters the angle, siril will handle this like in your example.


I checked the log. the files say rotation of 107 instead of 180 after the flip. So this is to be expected in that case.

I will check my mount and software.


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