Feedback from letmaik/rawpy#12 (comment) on the colour negative notebook that should be incorporated:

Right at the start, you should mention that the images used are photographs (not scans) of the negatives, saved as raw files. I don’t see why a similar process wouldn’t work with a film scanner, but most of them come with commercial software to do the conversions. Using a normal DSLR to capture the original negative is quick and easy.
At point 7, the reason that the green channel is used as the reference is that the DSLR sensor has twice as many green pixels as it has red and blue ones (the Bayer matrix), so that, in theory at least, it is the least noisy of the three channels.

Hi I have used rawpy for a while. I found there is some problem when the Fuji raw data (.RAF)

When I use rawpy to read Sony raw files, everything seems right: I can load the black_level, raw_pattern, etc. However, all these values are almost zeros when I load a Fuji raw file with the format RAF.

The raw_pattern is like:
[ 1 2 1 1 2 1]
[ 0 0 0 0 0 0 ]
...
[ 0 0 0 0 0 0]
And the black_level are also all zeros.

Can anyone fix this problem?