Thanks a lot for the time you're investing into this !
Originally posted by stevebrot Default settings to produce a 16-bit TIFF with the camera-designating white balance.
Code:
dcraw -v -6 -T -w <filename>
The default settings of DSS is -4 (not -6) which according to the help is equivalent to "-6 -W -g 1 1". The important part seems to be the "-W". Without it, I can indeed get redish tint on all my images. With it (like DSS), I reproduce my issue on the file with a Black Point set to anything else than 0.
Originally posted by stevebrot I also strongly suspect that the EXIF entries for black point are a red herring and reflect settings used for the in-camera preview JPEG creation
The Black Point EXIF seems to be used by dcraw :
Code:
>dcraw -v -j -t 0 -4 -d -T IMGP9837.DNG
Loading Pentax K-5 II image from IMGP9837.DNG ...
Scaling with darkness 513
And when "-k 0" is applied it gets discarded, which result in a redish image :
Code:
>dcraw -v -j -t 0 -4 -d -T IMGP9837.DNG
Loading Pentax K-5 II image from IMGP9837.DNG ...
Scaling with darkness 0
Finally, If I edit the EXIF Black Point/Level to 0 0 0 0, both command lines results in a redish tint. Setting the black point to its original value using "-k 513" produce a black image.
Code:
exiftool "-BlackPoint=0 0 0 0" "-BlackLevel=0 0 0 0" "IMGP9837 - Copy.DNG"
So the EXIF tag is vital for dcraw to load the image correctly.
From all that, I should indeed uncheck "Set black point to 0" at all times
I'm puzzled why the camera does change those EXIF and apparently the image data itself (if I'm getting this right) depending on the mode or ISO setting though ? Am I missing something from your explanation ?