DSS darks, flats, bias.

[Daddystu]

As the darks already contain the bias does DSS 'know' this and account for it? For instance if I load up my file list with lights, darks, flats and bias will it know not to subtract the bias from the flats in this instance?

[jgs001]

DSS subtracts the BIAS from all the frames, and it should work, although in my experience I've had problems with odd colour casts. To get around this, I loaded a single light frame, the bias frames and the flats, ran that stack to get a master flat... then went back to the list of lights, loaded all the lights, the darks and the master flat, and ran the full stack on that list, leaving out the bias. That process produced much better results for me.

[Daddystu]

Thank for that suggestion John. I shall give it a try. I have 10x10 minute subs of M51 and im trying to get the best possible results out of them. I've even group stacked them with 5 and 3 minute subs. There does seem to be more detail than im pulling out but the initial stacked image is requiring a heavy handed approach on curves, levels and contrast. The sky was quite light polluted at the time so I may have to admit defeat.