Unclear error with Photometric Color Calibration

Hello all

Question: at random the Photometric Color Calibration will give the error below. I mention at random because when I do the same FITS file again (in the same session or a restart), the error is not there.
And it looks like the calibration works just fine, so I wonder where the error is pointing to? It says selection, but what selection is ment?
This time it’s a double error but most of the time it’s just a single line.

14:00:16: Catalog NOMAD size: 1167 objects
14:00:16: 600 pair matches.
14:00:16: Inliers: 0.993
14:00:16: Resolution: 0.486 arcsec/px
14:00:16: Rotation: +90.82 deg (flipped)
14:00:16: Focal: 2028.07 mm
14:00:16: Pixel size: 4.78 µm
14:00:16: Field of view: 37’ 54.69" x 24’ 35.95"
14:00:16: Image center: alpha: 21h35m39s, delta: +57°30’12"
14:00:16: Flipping image and updating astrometry data.
14:00:16: Normalizing on red channel.
14:00:16: Applying aperture photometry to 595 stars.
14:00:22: An error occurred in your selection. Please make another selection.
14:00:34: An error occurred in your selection. Please make another selection.
14:00:36: 245 stars excluded from the calculation
14:00:36: Color calibration factors:
14:00:36: K0: 1.000
14:00:36: K1: 1.759
14:00:36: K2: 1.641
14:00:36: Background reference:
14:00:36: B0: 9.45804e-03
14:00:36: B1: 1.66651e-02
14:00:36: B2: 1.55193e-02

Please, could you share your image.

Here is an example. It’s NGC 6888 (FITS file) and it the calibration works.
But also here: one time no error, the other time the error mentioned above.
The example is not cropped but also here: cropped or not, the error is random there.
So no big issue, just thought I mention it :slight_smile:

File is on WeTransfer.

I tried your image, Can’t see any warnings.

However, I see you use a stack from DSS. For a better color handling you should use siril from scratch.

Thanks for looking into it.
And yes, at the moment I’m using both DSS and SiriL for stacking. I’m in the process of learning SiriL stacking outside the included scripts. Lot’s of trail and error but I’m learning :smiley:


An update on this just in case: I did find that this error happens most (with both SiriL and DSS stacks) when I use the Find option to find resolvers like NED and Simbad.
But when I use the Get Metadata From Image option, then this error never happens.