When entering the comparison and check magnitudes the help says:
"Comparison Star Magnitude
The instrumental magnitude of the comparison star that you used. A decimal point is required.
...
Check Star Magnitude
The instrumental magnitude of the check star that you used. A decimal point is required."
I have presumed (correctly I hope) that the "instrumental magnitude" as referred to elsewhere is the instrumental magnitude obtained by the photometry software (Iris in my case) and NOT the transformed magnitude for the Comparison and Check stars (using the derived coefficient) - correct?
Thanks in advance.
- Carl.
Hi Carl, all,
Interestingly this is different from the Citizen Sky form ! In any case we should use an "ensemble" process with DSLR. This is the way developed at CS with Brian and the best to determine the actual transform and extinction gradient across our large FOV. Then an "instrumental" value for the check has little meaning in our case. In most it can't be used to make a "back" check. Best to qualify the observation would be to report the sigma of the "ensemble" fitting, this is what I do for my own. Then I report the full processed check mag including DSLR, extinction gradient, atmospheric chromatism compensations (important for guys under urban skies, we do not observe at Paranal !) All this using my VSF technique.
Maybe we should put in the comment a note saying the check is processed ?
Clear Skies !
Roger
Hi Roger,
Firstly, thanks again for responding.
So using the DSLR observation (http://www.aavso.org/webobs/individual - Observation Type = DSLR) entry page:
Clear skies.
- Carl.
[quote=Carl Knight]
In case you submit transformed magnitudes then is should be "Johnson V".
TG is for untransformed magnitudes.
Clear skies,
Robert