Master Dark Frame "Problem" and Bayer/Mosaic Pattern Question

[twade]

To all,

I've been experimenting with calibrating my Canon 5D mk II images in the latest PixInsight Standard.  Due to a limitation in time, I could only get five 2-minute dark frames.  I took ten bias frames.  All images were shot at ISO 1600.  The master bias frame seemed to generate without any problems.  Keep in mind, I used Maxim DL to save the images as a RAW CFA FITS file.  I believe I followed the instructions correctly in all the tutorials, but you never know.    When I generated the master dark frame, over 50 percent of the dark pixels were removed.  This seems excessive.  I did use Winsorized Sigma Clipping.  Perhaps I should have just went with Percentile clipping?  I'm not sure if Maxim DL is automatically adding a 100 DN pedestal or not.  If it is, how would this effect things and how would I fix it?  Any suggestions would be greatly appreciated.

What is the Bayer/Mosaic pattern for a Canon 5D mk II?  I used the default, and the image was way too green.  It is usually way too red given the fact it is a modified camera for increased red sensitivity.  The color casts is likely easily fixed in post-processing; nevertheless, it's more of a curiosity than anything.

Thanks,

Wade

[ruediger]

What is the Bayer/Mosaic pattern for a Canon 5D mk II?  I used the default, and the image was way too green.  It is usually way too red given the fact it is a modified camera for increased red sensitivity.  The color casts is likely easily fixed in post-processing; nevertheless, it's more of a curiosity than anything.

Hi Wade,
when I started with PixInsight, my 500D and 5D II images looked also very green, but this was only the case when I left the "RGB link channels" checkbox in the STF activated (I used the default Bayer pattern for demosaicing).
I guess, the reason for the initial color cast depends on how the flats were taken: If they have a high blue intensity, like when making sky flats or when using a flatfield panel, the blue channel intensity is reduced during the calibration.
Regards,
 Rüdiger

[twade]

Rüdiger,

I really appreciate your comments.  My flats are generally red due to the modified camera (i.e. higher sensitivity to red) which messes up the color balance.  I'll continue to experiment with different options and processing techniques.

Wade