I am having a problem with reading dark red (R<=~50, G=0, B=0) colors with an
i3 Display Pro and an LG 32EP950 monitor, which is a true RGB OLED made by
JOLED.
Here is what I am seeing. Test patch R=19,G=0,B=0.
If I do a plain spot read, it returns after 12 seconds:
Result is XYZ: 0.000000 0.000000 0.000000, D50 Lab: 0.000000 0.000000 0.000000
This seems to be a timeout in the adaptive integration algorithm. If I add the
-Y A option, to not use adaptive integration, it returns instantly with:
Result is XYZ: 0.214069 0.105818 0.086582, D50 Lab: 0.955849 4.524206 0.013367
Of course, using -Y A across-the-board results in poor accuracy (though this
one patch doesn’t seem so bad, see next):
I also have an i1 Studio, and reading that same patch located in the center of
the screen, with -H high accuracy and printing out the spectral values returns:
Spectrum from 380.000 to 730.000 nm in 106 steps
0.000677863, 0.000677863, 0.000677863, 0.000677863, 0.000677863, 0.000677863,
0.000677857, 0.000612011, 0.000693905, 0.000761772, 0.000857883, 0.000117011,
0.000133197, 0.000201626, 4.35837e-05, 0.000385642, 0.000111682, 8.45398e-05,
1.12288e-05, 0.000150202, 0.000261324, 0.000201705, 5.98113e-05, 0.000387402,
0.00055555, 0.000289187, 0.000546194, 0.000414258, 0.000110531, 0.000117446,
-7.77059e-06, 7.71465e-05, 0.000192128, 0.000158629, 0.000181452, 0.000193961,
7.96003e-05, 4.06483e-05, 5.46237e-05, 0.000113624, 0.000266118, 0.000146872,
0.000128306, 0.000297609, 0.000465555, 0.000311087, 0.000142473, 0.000115165,
0.000150361, 0.000107005, 2.43133e-06, 2.17761e-05, 2.36204e-05, 2.53841e-06,
1.55331e-05, 6.00398e-05, 0.00019325, 4.33622e-05, 3.35985e-05, 7.31768e-05,
-6.43234e-05, 6.02323e-05, 0.000288822, 0.000580459, 0.00110143, 0.00195587,
0.00322639, 0.00465131, 0.00625067, 0.00788535, 0.009129, 0.0100662, 0.0103429,
0.0100887, 0.00966227, 0.0088194, 0.00800599, 0.00720781, 0.00643731,
0.00569174, 0.00510676, 0.0047117, 0.00433063, 0.00403085, 0.00376386,
0.00361477, 0.0033579, 0.00311389, 0.00289918, 0.00276145, 0.00258996,
0.00236596, 0.00210558, 0.0017656, 0.00149016, 0.00131391, 0.00116416,
0.00103563, 0.00098434, 0.000840669, 0.00064079, 0.000582421, 0.000618773,
0.000546276, 0.000494823, 0.000353341
Peak value 0.010343 at (aprox.) 620.0 nm
Result is XYZ: 0.220297 0.106411 0.016746, D50 Lab: 0.961207 4.752621 1.341096
Is this a timeout issue with adaptive integration? Is there a way to increase
the time beyond 12 seconds to avoid it?
Strangely enough, it’s not just Argyll that fails with these dark reds. LG’s
own LG Calibration Studio also gets zero results for dark reds.
-Ray
