Should we make anything out of the dE values in terms of the lowest being a custom DNG profile?
2nd place appears to be a custom ICC profile? If so, can you comment on the ease of building both sets and if they are easily transportable to other raw converters that support them?
In the data I sent you, I did a version whereby I blurred the Macbeth's and the results are about the same in, obviously the dE values are different (less) but the order presented here is the same.
Andrew, I'm not sure if I can adequately comment fairly on this matter.
The DNG profile that you ranked tops has not just the camera matrices but also a relatively high resolution LUT. The ICC profile is only a simple matrix profile, with a linear gamma tone curve. I would actually say that the ICC profile is better than a DNG profile with its LUT stripped off!
I'm not sure how a LUT ICC profile will behave. A few respected experts have warned to stay away from that if using a small patch target. It might be better, but it quite likely might be worse.
Creating a great ICC profile can be as easy as a DNG profile, if you have taken the time to set up your workflow with Argyll. I already posted the code that I used so anyone can just take it and punch it into a command line interface program, after downloading Argyll. You will also need another line of code to get Argyll to sample from the photo of the target and create a measurement file to build the profile from. The wonderful thing is that you can know what reference values Argyll uses, and modify that reference file to your own custom values. This is great if you have a good spectrophotometer and you use only one CC target for all your profiling. Otherwise averaged reference values like Danny Pascale's ones are fine. You can also create your own reference for a new target that Argyll does not have the reference file for. Unlimited control! If one is hindered by dealing with code, Raw Photo Processor has a GUI for camera profiling with Argyll. I haven't tested the consistency of Argyll's profile building process. The patch detection is automatic and so far my tests of other auto-detecting camera profiling software has shown it to be very consistent. That is, the profiles tend to end up almost exactly the same.
The DNG PE however, requires some manual user interaction by placing the control points on the corresponding color patches. It is very very sensitive. I have gotten errors like: "Non-neutral gray patches. The gray patch in row 4, column 3, has a significant color cast. Please re-shoot the chart carefully to avoid color casts and try again." Then a small shift of the control points and a perfect profile is produced, no errors. It is quite a weird one. It is always
this particular gray patch that it thinks is different. Tried two different colorcheckers. Tried different kinds of lighting. When a non-neutral warning appears, always this patch is the problem. I've also gotten overexposure warnings when the actual values in the white patch are not clipped. Again slight tweak of the controls and perfect profile again.
One of the problems with ICC profiles in the beginning is that the white point of the profile would be too low, because the white patch in the target isn't exposed as pure white, and it shouldn't. Unnecessary loss of highlight headroom was one of Adobe's arguments for DNG profiles. No longer is that an issue with scaling the white point for an ICC profile. I've yet to test how well ID handles highlights with DNG vs ICC profiles, but I think it should be quite similar now.
I haven't seen a single illuminant DNG profile that can adequately map a CC's values when the CCT of the light, assuming it has smooth spectral transmission, is different by 3000k or more. That's why I made warm daylight profiles for sunrise and sunset. Regarding the ability of DNG profiles to be able to describe a wide variety of lighting, a dual illluminant profile has greater success, for the average untrained eye. If the temperature slider in ACR/Lightroom is set between 6500K and 2850K, as it often is required for pleasant rendering of white balance across a wide variety of scenes, the profile would be subtly wrong, because it must interpolate from both illuminant tables. A 5000K daylight shot of a CC ends up being slightly less accurate than a well made single illuminant profile. Likewise for a 3850K warm daylight CC photo.
I've had great success bringing over an ICC profile I made for ID into RT. It renders the CC values quite well - the evidence is in the second tif file I posted. Surprisingly, the DNG profile in RT was a disaster because I suspect that RT is not supporting the latest DNG spec properly. Nothing to do with the flexibility of the format here, or the fact that it was built from scene rendered data, not raw converted output data. Raw converter software engineers will have to keep up with the changing DNG specs.