Hi all,
I use BPP to process my .cr2 files, to generate the stack image for processing. Recently I find that the master bias and master dark, have a higher signal than that of the original.
eg. If I open individual bias and change to gray format, the K value is usually around 0.0008 or lower. However, the master bias file ( which I assume is cr2->cfa conversion and then integrated ), has a value of 0.031 range. This is the same for my dark files, which individual ones should have very low value because I am using cooled DSLR but the master dark are also K=0.031 Thus the resulting integrated light file has very low and narrow range.
I tried to integrate the bias and darks without cr2->cfa conversion, and the resulting master bias/dark matches that of original ones. If I use that to do calibration, the end result of the light frame has a dynamic range that matches my original ones, a higher and wider range.
I wonder what's the mechanism here. It seems to me that a higher and wider dynamic integrated light is easier to process. Am I missing something here ?
Edmond
