I recently dusted off my RedCat 51 (purchased from the kickstarter campaign but not used until covid days). I am having a major challenge getting my flats to remove the heavy vignetting with a FF camera. I am sure this is user error and a rookie mistake but I'm a bit stumped.
To check my work I used pixel math to divide a single light frame by a flat frame ( $T/flat * avg(flat) ) and the result is not good. Similarly when I stack and integrate the entire sequence I end up with a nasty looking vignetted master light frame.
The details are:
scope: WO RedCat 51
camera: Canon EOS R modified
Flats were taken immediately following light frames, using a light panel.
Thanks in advance for your insight!