Kodak DCS 520c, issues with ISO

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fast raw decoding library

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Kodak DCS 520c, issues with ISO #311

Open PeterWem opened 3 years ago

PeterWem commented 3 years ago

This camera is when shooting in raw truly ISO less. ISO 200 or ISO 1600 are just the same. DCS 520c saves raw files in .TIF but darktable can't read those. Replacing .TIF with .DCR is a workaround.

Now the problem. darktable shows major sensor clipping in the raw file at ISO 1600. It should be identical to the raw file at ISO 200.

Skärmbild från 2021-10-09 14-15-56

Raw files and how RawTherapee works without sensor clipping https://discuss.pixls.us/t/darktable-increases-brightness-in-raw-file-with-no-way-back/27306

OS: Ubuntu 20.04 darktable 3.6.1

kmilos commented 3 years ago

Replacing .TIF with .DCR is a workaround

rawspeed actually thinks this is a Canon-style .CR2 file, DCRs are somewhat different... Perhaps something goes wrong w/ the GrayResponseCurve decoding (i.e. linearization), they are very different for the two files:

PeterWem commented 3 years ago

Canon EOS D2000/Kodak DCS 520c. It is a Canon 1N with a digital back from Kodak https://en.wikipedia.org/wiki/Canon_EOS_D2000

Canon created a software to convert Kodak DCS 520c raw files from Tiff to CR2. https://in.canon/en/support/0900000101 Edit: CR2 converter fails with Kodak DCS 520c but works with EOS D2000C even if they are the same camera. There are some differences in Exif and raw file size. I tried D2000C file from raw.pixls.us and compared.