Image histogram generated from what data?


#1

out of curiosity, is the histogram for a dslr image based on the RAW file or a compressed jpeg like backyard EOS??
I ask as id like to use the histogram to work out my flats exposure as I don’t know how to work out the ADU for a dslr.
Also is it possible for the histogram to show the colour channels for a dslr/OSC camera??
as its the red channel that is potentially the problem.
Thanks


#2

It is based on the raw data returned from the camera that has been scaled to 16bit.

For the ADU use the normal rules for CCDs. Set the peak somewhere between 20k-32k for flats.

Thanks,
Jared


#3

Thanks Jared
Ill give the 20K-32K a go in the flats wizard in that case.


#4

I hadn’t realized that DSLR data is scaled up to 16 bit. That’s good to know.


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