Astroart Forum

Hello,

perhaps a too simple question, but I couldn't find the answer in the Help files, the manual or the forum:

I'm trying to calibrate DSLR images of the different colors (RGB) photometrically (the ADU <-> Mag correlation).
As for photometry the UCAC4 catalogue with the APASS magnitudes is remommanded, I installed it.
Using the G picture, I select ApassV in the Star atlas setup ("Band"), and I suppose these V magnitudes are given in the Mag column.
Using the B picture, I select ApassB, and would suppose to see the B magnitudes in the Mag column, but these are the same numbers as before, though I deleted the calibration.
I then compared the Mag in the Stars window with the UCAC4 V magnitudes from VizieR (identifying the stars manually..), and they were also different....

What am I doing wrong?
How can I get the V and B magnitudes to calibrate the G and B images?

Thanks for help!
Best,
Andreas

Hello, after switching the magnitudes in the Star Atlas, it's required to repeat the link from the Star Atlas to the Image (from the Star Atlas, button: "Reference stars - automatic" or "Reference stars - manual").
If some stars with magnitude are already in the list, it's required to reset their "P Ref" flag (pressing P), or just to delete them all, before the link.
Fabio.