Guys,
I pre-processed a bunch of lights, darks, bias, and flats in BPP. These all came off my Nikon, so are NEF.
I let BPP do its thing. The adapter for my field flattener produces obvious vignetting. I was surprised that the flats did not compensate. After close inspection, the master flat produced by BPP needed to be vertically mirrored (I matched dust mote shadows in one of the light frames).
I had 'Up bottom FITS' unchecked in BPP. In PI I have the default coordinate origin: Upper left corner (up-bottom).
I realize that the coordinate origin doesn't matter if you don't mind your pictures being upside down
but clearly my image calibration was impacted in a negative way as the flats do not match the RAW frames.
Certainly I can just vertical mirror the master flat and rerun BPP. Is that all I have to do? My master dark and bias will not need this treatment, right?
Thanks,
Louis Marchesi
