Dark Frame Scaling

[Peter]

Hiya all, just loving Pixinsight and my headaches are starting to disappear as I come to understand the processes involved. On a learning curve I think I can finally sit on the lip before falling back down...yippee. So with my little bit of knowledge here goes what hopefully is a valid question. In Dark Frame Scaling is it necessary to create a thermal dark frame, i.e. removing bias from each dark frame? I ask because I don't know if this is taken care of in Pixinsight or whether it is required for the user to create a thermal frame for scaling? Hope this is a valid question or otherwise it appears I am sliding down that learning once again. But despite this probability of descent I am just amazed at what you guys have created in PI and all those Masters that have processed their work with said creation.   

[pfile]

you can do it either way. if you have a "plain" master dark, you can load a bias and dark into ImageIntegration and check "calibrate" beneath the dark filename in the dark section the II window.

if you precalibrate your master dark, then leave "calibrate" unchecked.

note: i don't know what the batchpreprocessing script does, someone else will have to answer that.

[Peter]

Cheers pfile and thank you for clarifying my inquiry into calibration, you are a bro,

[Cleon_Wells]

Here's a link to more info on Dark Frame Scaling, this maybe more  then you want to know right now, 

http://pixinsight.com/forum/index.php?topic=4161.0

I use a Canon T1i camera and have seen problems Calibrating the Dark subs ((subtracting the Bias from the Dark subs which creates the  c.fit files from the raw DSLR Dark files))  before Debayer and ImageIntegration, creating a Calibrated MasterDark. I just use BatchFormatConversion on the raw Dark subs, BatchDebayer then ImageIntegrate creating a unCal MasterDark. I check the Cal box in the MasterDark section during ImageCalibration of my Lights frames. My Dark Frame Scaling factor on my raw Light frames is around 0.8