A few of you have asked over time how reliable Mac calibration via ColorSync actually is, and whether a 3D LUT embedded in a Display ICC profile genuinely gets used on macOS. Short answer: it depends on the application, and even Apple's own position on this has changed over the last few macOS releases without much documentation of the fact.
We've put together a full technical page on it - what ColorSync does and doesn't do with a display's assigned profile, the difference between that and general ICC colour conversion (which has always worked fine, that's how print profiles and Look/LUT burn-ins have always worked), and the actual workflow for building and verifying a Mac calibration with ColourSpace, PatternSpace, and SpaceMan.
https://lightillusion.com/mac_colour_management.htmlThe SpaceMan manual has also been updated with the macOS-specific steps for adding the matrix/TRC tags a Display Class profile needs for macOS to have anything reliable to fall back on.
Steve
Steve Shaw
Mob Boss at Light Illusion
