I use Newtonian Reflectors 6” to 12” for imaging
I’ve tried Calibrating with Dark flats and Bias
Bias work best for my 2600MC
I set exposure in APT to 0.000032 sec and take 60 Bias
My Flats are taken with white t shirt and Huion LED dimmable light panel
ADU target is set around 19,000 to 20,000 for a histogram range of between 8500 to 33,000 or up to half way
Flats exposures with no filter (broadband) are around 0.2 to 0.5 sec
Flats exposures with L Extreme or Antlia Dualband filter (narrowband)are around 3 to 5 sec
I take 40 Flats
Clear Skies