Stellar Photometry With DSLR: Benchmark of Two Color Correction Techniques Toward Johnson’s VJ and Tycho VT
Roger Pieri
37 C rue Charles Dumont, Dijon, 21000, France
Received April 24, 2012; revised June 18, 2012; accepted August 17 2012
Abstract
DSLRs are now routinely used for measuring the V magnitude of stars through their G channel output. This requires a transformation to Johnson V, using a correction based on the catalogue (B–V) color indices of the stars. This paper reviews the responses of the involved passbands and proposes an alternate solution using a synthetic filter made by combining the three RGB DSLR channels. The assessment of the two techniques through experimentation being uncertain, we have chosen to use a computer simulation instead. This simulation combines the measured spectral responses of the DSLR channels, the atmospheric reddening, and star spectra from the Pickles library.