This was the last test:
(7) Intensity: 120cd/m2, Contrast: Default, [Average low light measurements]: On, Calibration steps: 32; Calibration priority: Best greyscale colour tracking
DeltaE Results: White Point: 0.62; Colour: 0.48 (0.43 including dark values) average, 0.70 maximum; Calibrated black level: 0.34.
I still have to try increasing the calibration steps and increasing the luminance. My preconception is that increasing the calibration steps will make little or no difference but increasing the luminance may make a significant difference.
What I actually found was quite unexpected:
(8) Intensity:
120cd/m2, Contrast:
Default, [Average low light measurements]:
On, Calibration steps:
52; Calibration priority:
Best greyscale colour tracking
DeltaE Results: White Point:
1.46; Colour:
1.14 (0.96 including dark values) average,
1.58 maximum; Calibrated black level:
0.34.
Spectraview II Manual said:
A larger number of steps will generally result in a more accurate grayscale calibration, but will increase the calibration time. 32 steps is the recommended setting for most applications.
Here, increasing the steps from 32 to 52 has resulted in a significantly poorer profile. I found this so remarkable I reprofiled with 32 steps again, then 52 steps again, then 32 steps again:
(9) Intensity:
120cd/m2, Contrast:
Default, [Average low light measurements]:
On, Calibration steps:
32; Calibration priority:
Best greyscale colour tracking
DeltaE Results: White Point:
0.87; Colour:
0.76 (0.64 including dark values) average,
0.97 maximum; Calibrated black level:
0.35.
(10) Intensity:
120cd/m2, Contrast:
Default, [Average low light measurements]:
On, Calibration steps:
52; Calibration priority:
Best greyscale colour tracking
DeltaE Results: White Point:
1.00; Colour:
0.86 (0.72 including dark values) average,
1.15 maximum; Calibrated black level:
0.33.
(11) Intensity:
120cd/m2, Contrast:
Default, [Average low light measurements]:
On, Calibration steps:
32; Calibration priority:
Best greyscale colour tracking
DeltaE Results: White Point:
0.87; Colour:
0.74 (0.64 including dark values) average,
0.99 maximum; Calibrated black level:
0.34.
Tests 9 and 11 were both very similar but higher than Test 7 from the night before. The monitor was well warmed up in both cases so I guess it's something to do with the extremely warm temperatures we are having at the moment.
Test 10 had settled down somewhat from Test 8, perhaps also for reasons related to the record sustained high temperatures here, but profiling at 52 steps is showing worse results than testing at 32(!).
Next I tested at Intensity of 130cd/m2 and 140cd/m2 and once again the results were unexpected:
(12) Intensity:
130cd/m2, Contrast:
Default, [Average low light measurements]:
On, Calibration steps:
32; Calibration priority:
Best greyscale colour tracking
DeltaE Results: White Point:
0.97; Colour:
0.85 (0.72 including dark values) average,
1.14 maximum; Calibrated black level:
0.33.
(13) Intensity:
140cd/m2, Contrast:
Default, [Average low light measurements]:
On, Calibration steps:
32; Calibration priority:
Best greyscale colour tracking
DeltaE Results: White Point:
0.99; Colour:
0.86 (0.74 including dark values) average,
1.19 maximum; Calibrated black level:
0.36.
Profiling at 130cd/m2 and 140cd/m2 yields poorer results for me than profiling at 120cd/m2. This is presumably because my monitor is no longer new. Often it is difficult to reduce the brightness level too far on new monitors and still get goodresults.
So I've gone back to profile #7 and am using that. What I suspect all this shows is that everyone should do these sort of tests to find what works for them with their particular monitor and working environment. Also, I suspect that it may be a good idea to do some tests every 6 months or year (or when major upgrades of the software appear) to determine whether the optimal settings have changed for you. On the other hand, there's no point getting too concerned about small changes in the results that are below the level for human discernment.
Regards,
Murray