Wrong flag Flipped in fits after MF

Pls analyse this, images after auto MF have wrong Flipped sttatus, pls see picture:
Pls note that the dot on the flat is from after imaging!!

Your images clearly show that there is a new dust donut in the flat frames that is not present in your light frames, that’s all. The issue has nothing to do with the ‘FLIPPED’ FITS keyword.

Please note that “flipped” means the same as “mirrored”. That is different from “rotated by 180 degrees”, the operation that is performed with a M.F.! I guess this ambiguity is an issue of the english language: the “meridian flip” is NOT a flip, it is a rotation by 180 degrees.


Yes, a new dust indeed, but why 2 spots on the image?
I think It should be one.
Regards Hugo

Relative to the sensor position, the target is rotated by 180 degrees by the meridian flip and the dust donut is not. This is the reason that the dust donut is displayed twice, and this result is expected.


So far I agree BUT!!, this means then that I need 2 flats, one before the flip and one after…
Or turn the flat for 180 deg.
Pixinsight should correct the MF and use only one flat:
I reported the issue by PI:

The 2 dots are correct, the image is rotater by the MF, the erro not.
So there is no problem.