[avandonk]

Gave the 150mm f/4.25 achro a run. 10x8 min at 800 ISO, 16x16 min at 800 ISO. Canon 5DH with Astronomik 13nmHA filter. Used both stacked exposures to produce a HDR image. If the weather is kind will collect O3 and colour. If you look carefully you can see three outer loops. If you have imagination you can see the fourth. The vertical 'noise' bars or lines is the variation due to bias. Yes folks this shows the lot from noise to max signal!

I did all flat, dark and bias corrections in mono bayer filter array or 16 bit fits. That way all corrections are done at the individual pixel level not at the colour level where interpolation has already occurred. When you are trying to get very faint data this is the only way to go. I then converted to colour tiffs before stacking in RegiStar. I only stacked the red data as a tiff because any blue or green noise interferes or distorts the stacking.

Bert