I am trying to calibrate a photometric measurement using reference stars in the field.
If I select an area around a star and select “PSF” from the drop-down menu, and in turn perform this for several stars with known magnitudes from an AAVSO search chart, I get a nice, consistent magnitude offset to apply to the target.
However, if I in stead use the “Pick a star” in the drop-down, I get a non-linear response, useless for calibration:
Image Information > Dynamic PSF also gives this non-linear result.
I checked the same image using the python SEP package and got a nice result, similar to the PSF method.
Could I have configured something wrong, or does this point to an issue with photometry in Siril?
Using linux Siril-1-2-1-x86_64.AppImage