Yes, it’s cyan, not dead-central green, though surely the exact color is camera-dependent. This doesn’t change anything at all. And as I keep pointing out, sRGB is not involved in the example that I gave. It’s just not involved:
-
Make matrix camera input profile using a target chart white balanced to D50. Or else just pick the dcraw default input profile or when using darktable, the enhanced profile if it’s available for your camera.
-
Interpolate a raw file but use uniwb.
-
Assign the camera input profile from step one and review the results using ICC profile color management and a calibrated and profiled monitor.
sRGB isn’t involved in the above 3 steps.
Has anyone actually bothered to check the simple steps outlined above? All you have to do is open a raw file using darktable and disable the white balance module - does the raw file have a green (cyan) color cast? Yes or no?
If you don’t want to use darktable, I gave the dcraw commands.
If you don’t want to use dcraw, try PhotoFlow and choose “Area” or “Spot” to reset the multiplers to uniwb.
Anyone? Please? Open a raw file and follow the three steps? Does it look (cyan) green or not?
If it looks green, and it eyedroppers as a green color, what does it mean to say “it’s not green”?
The reason it looks and actually is green is because it wasn’t properly white balanced to go along with the way the target chart was white balanced when the input profile was made.
The shape of the camera matrix input profile is irrelevant. Most of the space is just wasted because of how the primaries are calculated to fit the supplied data from the target chart shot. Most of the image channel values will fall within the xy values inside the “horseshoe shape” on the xy plane that includes all real colors.
Only bright saturated yellow/yellow-green and dark saturated violet-blue typically cause any issues with falling outside the realm of real colors. Though laser lights and neon lights (and stars?) and such also will cause issues - these sorts of colors are outside the usual target chart color patches.
If it looks green because it was improperly white balanced, it’s still green. The solution isn’t to say “it’s not green”. The solution is to go back and apply the right white balance.
Is the red target chart shot in @shreedhar’s third example (post #82 above) “not really red”? It sure looks red to me. And it’s red because it was given a white balance that is not in agreement with how the “uniwb” target chart shot was white balanced before making the input profile.