Trying to profile my ID1pro to my Jeti 1501, I have had some issues as I could not understand why the cromaticity red accuracy was below than expected.
After some investigation, and discussions with Ted and Steve, very kind to listen to me, here what I have found out:
I have based profiling on wide gamut, and on CMF display, as advised.
When I read red with my ID1 I get the following:
. The peculiarity of that red is that it is out of CIE. Its Z is negative.
Anyhow, If I read all the colours for generating the profile I get something of different:
and its Z is 0, but if I click on measure the orginal value is taken:
At this point I have tried to validate the the accuracy of the corrections I get: I have used generic CMF and wide and normal Gamut readings, and WRGB Oled and wide gamut readings. In one case not caring about negative Z. After profiling I have check WRGB with normal (rec709) and Wide gamut setting.
Here the outcome:
My conclusion: It looks that the algebra existing behind XYZ correction is not jeopardised by negative Z. Honestly I cannot tell if this is peculariar to my meter, but from now on, I will take a special care to red position when doing profiles based on wide gamut