Hello,
I agree that it would be nice to have the offset value in the FITS Header.
EKO, and most other astrophotography tools have two ways to handle image data, 1 or 2 Byte per file, thus 8 or 16 bit. I doubt, that the fits format would even allow 12 bit files. 8, 16 and I think even 32 used more or less widely.
While the camera delivers 12 bit values, the remaining 4 bits are filled with zeros, effectively multiplying the value with 16. So you will have values in the range of 0 to 65535 instead of 0 to 4095 but all you values are multiples of 16.

So in short, I you do not want to use 8 bit, chose 16 and you will receive what you camera delivers.

Regards

Dirk.

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