Comparing i1Pro, i1Pro2, i1Display Pro and Discus

[MichaelKoerner]

For color geeks only: I wanted to see the differences in color tracking when profiling my NEC PA271Q with SpectraView II and different colorimeters/spectrophotometers (i1Pro, i1Pro2, i1DisplayPro, Basiccolor Discus). For this test I used DigitalDogs settings (5750K, 2.2, 150cd, 300:1).

See the results attached. Interestingly, the (rather old) i1Pro performs not too bad in this particular situation...

[digitaldog]

Also for those using the old i1Pro Spectrophotometer, seems end of life support is now here, at least with the last update to i1Profiler. 

[Alan Goldhammer]

Also for those using the old i1Pro Spectrophotometer, seems end of life support is now here, at least with the last update to i1Profiler. 

Yup, they want us owners to buy a new Spectro!!  I use ArgyllCMS for profiling and it's just happy with my i1Pro and as long as it keeps working fine, I'm happy.

[MichaelKoerner]

I did a similar test, this time using D50, 1.8, 75cd "print" settings. Leaving contrast ratio to "native" I observe a remarkably lower contrast ration when measuring with i1Pro (old) compared to measurements with Discus or i1Display Pro.

What could be the reason - construction? Old filters/lamp? Just wonder whether this would get in the way of further usage of this nice piece of technology...

[digitaldog]

http://lumita.com/site_media/work/whitepapers/files/xrite-wp-3a.pdf

[MichaelKoerner]

Andrew,

thanks for the link to the description of differences between colorimeters and spectro-, yes, in this case, radio-, not photometers.

In my first post I did not include the results from i1Pro2 (updated now). The results show contrast ratios of
560:1 with i1Pro (Spectro.)
863:1 with i1Pro2 (Spectro.)
917:1 with i1Display Pro (Colorim.)
989:1 with Discus (Colorim.)

Even compared to i1Pro2 i1Pro falls behind, that's why I wonder whether there could be a specific problem with it.

Apart from that I learn from those tests that the 4 measurement tools are - concerning results shown in SpectraView II - pretty comparable. Measurement targets (contrast, white-point etc.) seem to have a bigger influence on dEs then the device used.

Please confirm/disagree, if possible... Thank you!

[Czornyj]

i1Pro rev. D and E has potential issues with low luminance measurements - rev. E is better thanks to electronic compensation of dark current noise. Both spectrophotometers have too small FWHM resolution to calibrate PFS W-LED IPS type panel precisely. i1Pro rev. D also has worse inter instrumental agreement than rev. E, which uses electronic spectral compensation while calibrating by measuring green LED emission.

Discus and i1D3 have way better low luminance accuracy, good enough to handle PA271Q.

Discus has poorer agreement with standard observer CMF, so it heavily depends on specific panel calibration correction. The question is if it has correction for PA271Q, which is doubtful.

i1D3 has usually better agrement with standard observer CMF, but there's no spectral calibration for PFS W-LED IPS that SVII can use, so it's also not ideal.

PA-series cannot be relinearised by SVII, so validation results are factory calibration quality dependent. All PA-series are usually perfectly 3DLUT calibrated with lab grade Konica-Minolta spectroradiometers and pseudo-XYZ colorimeters, so it's actually a good idea to use MultiProfiler rather than SVII and popular calibration sensors.

[digitaldog]

To add to Czornyj has written, there’s also the new i1 Display Pro PLUS. Just got one. Nice to see it worked out of the box with SpectraView. I got slightly better reporting from that device but the better results were invisible dE values but better none the less. 

[MichaelKoerner]

Thank you for your replies!

My i1Pro is rev. D :-/
According to basiccolor.de, my Discus needs to be recertified, then uploaded with PA271Qs correction matrix. I will check on that.

Can hardly believe factory calibration could provide better results than Discus with SPII, but your arguments sound comprehensible, Marcin.

Next step will be tests with Basiccolor Display 6. It's reports show lower dE(00)s than SPIIs dE(94), but I have to check how comparable those values are...

[Czornyj]

To add to Czornyj has written, there’s also the new i1 Display Pro PLUS. Just got one. Nice to see it worked out of the box with SpectraView. I got slightly better reporting from that device but the better results were invisible dE values but better none the less.

PLUS works better with i1Profiler, it seems to measure more precisely very dark patches. I'm not sure if it works that way in SVII yet, as I don't see a noticeable difference there - it looks like it's not fully supported as PLUS. The PLUS is still tagged as rev. B-02 like normal i1Display Pros, so I guess that the difference might be software related only.

[Czornyj]

Thank you for your replies!

My i1Pro is rev. D :-/
According to basiccolor.de, my Discus needs to be recertified, then uploaded with PA271Qs correction matrix. I will check on that.

Can hardly believe factory calibration could provide better results than Discus with SPII, but your arguments sound comprehensible, Marcin.

Next step will be tests with Basiccolor Display 6. It's reports show lower dE(00)s than SPIIs dE(94), but I have to check how comparable those values are...

I measured my new PA311D using high resolution FWHM spectrometer, and factory calibration seems to be deadly accurate:
https://forum.luminous-landscape.com/index.php?topic=133066.msg1141352#msg1141352

[MauriceRR]

If I understand, You created a profile based on measurements made with one tool, and then you measured the result with the same tool.
I see some methodology problem here.
Same for software probably...