I am new to photometry and am in the process (with my student) of preparing a master bias frame in AIJ from raw bias frames created on a Canon EOS T6i DSLR camera. It appears that AIJ does not recognize Canon RAW files, but requires bias frames to be input in FITS format. Does anyone know of a good free package (or online site) to do the conversion, preferably in batch mode?
I don't do a lot of DSLR work anymore but DeepSkyStacker and Fitswork are two that will probably do what you want, both are free. There are probably others as well.
I have found the free software ASTAP to be very convenient to convert DSLR files, either Canon or Nikon, to fits format. There is a batch conversion tool that works quickly and smoothly. There are many other useful features to ASTAP, including stacking, image calibration, etc., and a photometry tool. Rick