The DNG files produced by the GRDII (and GX100) for that matter contain 12-bit data (numbers between 0 and 4095). This data is mostly linear, but less so in the highlights, which can lead to a magenta cast in extreme highlights.
The DNG standard allows manufacturers to indicate the fraction of the range in which the response can be considered linear using the LinearResponseLimit tag. In Ricoh's cameras, this is set to the default value of 1.0 (fully linear response). A value like 0.9 (exact value to be determined by Ricoh engineers) is more appropriate and really cleans up the highlights.
For testing purposes, I have used ExifTool (http://www.sno.phy.queensu.ca/~phil/exiftool/) to change this tag on the overexposed doorway shot that I downloaded from this site (thank you for making the raw files available!). For the results, and a more detailed explanation, see http://forum.getdpi.com/forum/showthread.php?t=757.
I hope that this will be fixed in a future firmware version. It should be an easy fix.
Cheers,
Simon
The DNG standard allows manufacturers to indicate the fraction of the range in which the response can be considered linear using the LinearResponseLimit tag. In Ricoh's cameras, this is set to the default value of 1.0 (fully linear response). A value like 0.9 (exact value to be determined by Ricoh engineers) is more appropriate and really cleans up the highlights.
For testing purposes, I have used ExifTool (http://www.sno.phy.queensu.ca/~phil/exiftool/) to change this tag on the overexposed doorway shot that I downloaded from this site (thank you for making the raw files available!). For the results, and a more detailed explanation, see http://forum.getdpi.com/forum/showthread.php?t=757.
I hope that this will be fixed in a future firmware version. It should be an easy fix.
Cheers,
Simon