Thank you. Your information is very helpful.
You ask, what I want to do?
I want to observe the variable star R Crb in all four layers of my EOS200D,
and compare the instrumental magnitude with the comparison star and the check-star:
R Crb 15 48 34 +28 09 29
HD141352 15 47 41 +28 28 44 V=7.430 (B-V)= 0.471 (Comparison star)
HD140913 14 45 07 +28 28 13 V=8.060 (B-V)= 0.612 (Check star)
I hope to do this with a precision of 0.005 mag, if possible. Stetson observed with an precision of 0.002 mag, but on much fainter stars.
When one looks at the photometry of AAVSO, the errors in B and V are huge compared to Stetson. Even in the transformation standard cluster M67.
I don’t expect Siril to do the transformation from Canons RGB to Johnsons BVR, but I would like to get the instrumental magnitudes with 3 decimal places. In the file STARS.csv I can see, that the format is only 2 decimal places. [After doing Analyse → Dynamic PSF]
Has anyone made a “road-map” for an observer like me?
You have most likely made fine documentation on this. Where?
My french is rather rudimentary, but google.translate is a fine help, if you know what to translate.
Thank you for making this wonderful astronomical software.
Yours
Søren Toft