Affiliation
Magyar Csillagaszati Egyesulet, Valtozocsillag Szakcsoport (Hungary) (MCSE)
Thu, 01/20/2022 - 14:19
Dear Friends,
I'm aware that the "TG" magnitudes of Canon DSLR cameras are quite close to Tycho V mamgnitudes (VT) - as I can recall, Roger Pieri wrote about this in JAAVSO several years ago. I wonder whether anyone has already checked Nikon DSLR cameras with similar approach.
One of our observers want to use a Nikon 5100 camera for ZAND, RCB, mira and SR variables. Will be "TG" magnitudes of a Nikon 5100 DSLR camera be useful?
Thanx,
Robert Fidrich
HAA/VSS
Robert,
As far as I can tell, the spectral response curves for the R, G and B filters of the Nikon D5100 and some Canon cameras (e.g., EOS 450D, EOS 550D) are generally similar.
In my opinion the Nikon camera should be fine for DSLR photometry.
Roy
"Generally similar" -- do you have any study on this similarity or we can just hope the RGB filters of Nikon cameras have similar color response as Canon cameras have?
Robert:
Yes, the assumption is that DSLR Bayer array BGR filters in common DSLRs are the same and also the same as typical astrophotography RGB filters. Report as TR, TG, TB.
Ideally you would generate your own transformation coefficients and transform your magnitudes to J/C BVR.
Since no one really wanted to provide that data when asked a few years back, the info is not well documented!
Ken
The "generally similar" comment was made after visual inspection of the spectral response curves, which were not accompanied by any tabulated data.
Roy