A question about calibration without darks

[lensman57]

Hi to all,

While I was replying to another post this question came to my mind and I don't know the answer to it so here it goes. While calibrating, lets say in  DSS or Neb3, the first step is to make a master bias then subtract this from the flat frames and then stack the flats, from here on bias does not figure in the proceedings as the bias in the lights is taken care of when the master dark is subtracted . Now like many others I do not take darks with my CCDs, at -20c it is not necessary. I would like to know if the software subtracts the bias from the lights if bias is not in the equation or the software expects the darks for proper calibration. In  Neb3 one can subtract the bias manually from the lights but DSS does things on Auto, so does PI if the script is used, so how can we make sure that the lights are calibrated correctly if no darks are taken?

Regards,

A.G

[martin_h]

Like you say in Neb 3 just use the bias manualy.....in DSS its a bit more complicated because it seems a bias (if used) is subtracted from everything. So you could do what I do, use a bias subtracted master flat and instead of a dark use a bias frame in its place.....ie click to load a dark but use a bias instead....DSS will moan that its the wrong time length but ignore that.

[Psychobilly]

There was a thread back in 2011 in which DSS's calibration methods was discussed at length and RobH got in touch with the DSS developer (Luc)  for his  input...

The key comments on how DSS handles calibration  are in this post...

http://stargazerslounge.com/topic/90917-calibration-in-dss-is-it-doing-it-wrongresponse-from-luc-of-dss/?p=901660

Peter...

[lensman57]

There was a thread back in 2011 in which DSS's calibration methods was discussed at length and RobH got in touch with the DSS developer (Luc)  for his  input...

The key comments on how DSS handles calibration  are in this post...

http://stargazerslounge.com/topic/90917-calibration-in-dss-is-it-doing-it-wrongresponse-from-luc-of-dss/?p=901660

Peter...

Thank you very much Peter for posting this interesting link, I have only been in imaging for a little short of a year and there are still a lot of questions unanswered for me.

Regrads,

A.G

[Psychobilly]

Your welcome...

Peter..

Badly typed on my Galaxay S4 in Tapatalk4

[bronmw]

Just when things were starting to make sense ⊙_☉

[dph1nm]

DSS works fine if you just give it flats and biases (which is how I work). There is no requirement to upload a dark.

NigelM