We need to do a lot more sampling of users and camera types before we go out and say for a fact there's an issue here. Lets say Adobe (Thomas) tweaks the existing profiles. Do we know for a fact that a larger audience would have other color issues? The tool exists so any user can tweak the calibration. I'd be pretty shocked if everyone needed to do this BUT Thomas. He's a pretty bright guy, knows a thing or two about image processing, Raw rendering and color management (he wrote the application that builds the Adobe ICC profiles installed, the DNG converter and originally Photoshop).
You seem pretty sure of yourself that this is a systematic issue with the calibration, with not much to back it up other than personal experience. If you have more solid numbers, we're all ears.
[{POST_SNAPBACK}][/a]
Available information is strongly suggestive that there is a systematic problem with the reds in the default ACR calibration, and no data to the contrary have been presented. However, before we jump to rash conclusions, we should look at the entire situation, not just the reds.
The following quote by DPL of Thomas Knoll is illustrative of the problem:
“Actually, to create a camera filter set that is "perfect", it is not required to exactly the match the human cone responses (or the XYZ responses). All that is required is the filter responses be some linear combination of the human cone responses. If that is the case, then a simple 3 by 3 matrix [space] can be used in software to recover the exact XYZ values.
If the filter set is not a [perfect] linear combination of the cone responses (which is the case for all current cameras), then any color calibration is going to be some kind of comprise, getting some colors correct and other colors incorrect. This is true even if you know the exact illuminant spectral curve and the exact filter spectral response curves.”One can use a least squares method to minimize total RMS error or one can calculate the matrix coefficients to minimize error in colors that are thought to be important such as flesh tones, blue sky and foliage, which are important memory colors. One such approach is given [a href=\"http://color.psych.upenn.edu/brainard/papers/bayesColorCorrect.pdf]here.[/url]
For the Nikon D200, the overall accuracy of the default ACR rendering of the Greytag color checker is actually slightly superior to that of Nikon Capture NX even though the ACR reds have the mentioned bias.
ACR default rendering:
Nikon Capture NX (normal contrast, normal saturation setting on camera):
For your information, patches 1,2,3,4 and 15 are respectively dark skin, Caucasian skin, blue sky, foliage, and red.
For different illuminants and different surface colors, no one set of matrix coefficients will give optimum results. Mr. Knoll's calibration likely gives the results he wants for best overall results, but it may not be optimum for reproducing the red patch on a Macbeth Color Checker.
Bill