In another thread
finearttelier noted strange behavior using custom (non D50) illuminants when making and using profiles.
He discovered a major behavior change in I1Profiler which produces profiles unusable for soft proofing (Perc., Sat., and Rel. intents) and wildly wrong when printing Absolute Colorimetric.
Oddly, soft proofing seems to work in Absolute Colorimetric but what gets printed is wildly off.
The change can best be demonstrated by printing neutral (gray) colors. A neutral color has the advantage that it can be printed with a fairly flat spectral response on modern printers with a multitude of gray inks. And it also, by definition, retains it's neutral appearance under any illuminant since the CIE xy coordinate is unchanged and matches the illuminant's white point.
So I took the C4 patch on a standard colorchecker as a reference and printed the gray patch on MP101 matte with my Pro1000 using 3 profiles. These were made with standard illuminants D50, F2, and A, from the same measured patch set.
The Lab value for the patch was entered as L*=67, and a*=b*=0.
Here are the Lab values of the prints using the three profiles from each version of I1Profiler:
For version 1.7 of I1Profiler
D50: L*=67, a*=0, b*=0
F2: (4200K CCT) L*=67, a*=0, b*=0
A: (2800K CCT) L*=67, a*=-1, b*=1
For version 3.0.0 and 3.1.1 of I1Profiler
D50: L*=67, a*=0, b*=0
F2: (4200K CCT) L*=67,
a*=3, b*=9A: (2800K CCT) L*=67,
a*=16, b*=35The orangish red color is a long, long way from neutral gray and under tungsten it is really very red compared to the C4 patch on an adjacent Colorchecker.
One side effect of this change in I1Profiler is soft proofing reverses things and displays the "neutral" patch that actually prints red with a strong blue cast (using show paper color) . Completely the opposite of what gets printed.
But there's another problem that makes this option completely useless. V1.7 I1Profiler was useful for making prints that would be used in office environments which typically use F2 fluorescent lighting. These have very little red wavelengths and the result is that red colors look very subdued and magneta/pinks look kind of bluish. The older I1Profiler could compensate for this by selecting the F2 illuminant when making profiles. Under daylight the red/orange colors look pretty exaggerated but when hung in an office with crappy lighting they look quite good. This was the purpose of this option. The V3 I1Profiler screws this up. It produces essentially the same (aside from rounding errors) prints as just using D50.
So this option in V3 has been rendered useless.
XRite: Please fix this.
