This is going to sound like a stupid question to lots of people since it's not worth the effort except as an educational personal science project maybe, but I was messing with using Argyll CMS this weekend to create ICC profiles for camera calibration, and the ability to create a definitions for custom charts, combined with the fact that all I have is a ColorChecker, got me to thinking.
Unless I'm missing something, it seems like I should be able to pick some useful range of colors, print a chart with say 300 patches on my printer without regard to any existing target standards, create a CHT file for the layout of my chart, then measure all of the patches manually with a spectrophotometer to create the CIE file containing all of the Lab measured values. Assuming I pick good colors and I have a printer that can print them (the really dark ones sound the most difficult), it seems like I ought to be able to use the chart to create a decent LUT-based camera profile.
Given that I have an Epson R3000 (UltraChrome K3, etc) and a ColorMunki Photo, what would the issues be if I wanted to create my own personal digital camera color profiling target like this?
I understand only the most basic issues with limited numbers of pigments, metamerism, lack of diversity in spectral reflectance distribution of patches, gamut limits of the inks involved, and the amount of work required to measure 300 or so patches with something like a ColorMunki that doesn't really have a sensor aperture that's suited to reading lots of little patches, and stuff like that. But I don't know exactly how to quantify how useful or useless a chart printed with something like UltraChrome K3 pigments would be in terms of pigment diversity or gamut range for the purpose of profiling a digital camera under various lighting conditions.
Even if it works reasonably well it's not likely to be the greatest value for the effort compared to just buying a target, but it might be worth doing as a self educational science project.