Calibration of Dark subs

[Cleon_Wells]

      To Be or Not to BE,  Dark sub Calibration


Astropixel did a great job in collecting/summarizing the document from the Adler Planetarium  workshop on Calibration.

“ Calibrating the Dark Frames
Once we have the master bias image, we can subtract the bias pedestal from the dark and flat frames. “

from this link

http://www.astrofoto.es/Adler/Documentation/Calibration/Calibration.xpsm
“ As we are going to subtract the master bias pedestal to the dark frames, only the section must be activated “

Correct (I think) Master Dark creation
http://www.pixinsight.com/tutorials/master-frames/en.html

Can we come to an agreement on MasterDark creation for DSLR imaging?

[astropixel]

I think both methods are valid. One tutorial compliments the other. They do however, start in different places. The first does not address DSLR_RAW conversion, while the second does. There are two approaches to the problem and for one or the other according to preference both are acceptable. The developers have gone into print in relation to the reasons for DSLR_RAW conversion during image calibration and that is the basis of the DSLR_RAW workflow.

I think some image sets are problematic, which doesn't warrant changing either approach, or choosing one over the other in my view.

Cheers,

Rowland.

[Cleon_Wells]

Rowland, I should have said, To Be or Not To Be, Dark sub Calibration on my MAC. There seems to be something wrong with Image Integration/ Winsorized Sigma clipping and No Normalization settings for files that are very low in signal, like Calibrated Dark subs. All these same CR2 files worked perfectly on my Windows 7 PI install and when I used the Windows created WinMaterDark on my MAC for Calibration of the lights the Calibration worked properly. See attached screen shoot
Cleon

[astropixel]

Interesting. I'd have no way of comparing with a single install.
Persistence pays off.