Please help me interpret results of Calibration

[Bachir Messaouri]

Hi,

I have an iMac Pro and I used a I1Display Pro to calibrate and profile it.

I first used i1Profiler software and here are the settings I used:

– IMac
– GB-Led
– CIE D65
– Luminance: 120 cd/m2
– Gamma Standard 2.2
_ Contrast report: native
– No flare correct
– No native control of ambiant light
-Patch set  of 461 units
– ADC On
– RVB manual settings Off

Those are more or less the standard settings that were advised on the web for iMac
The result is a bit more yellow than my eyes expected and way more yellow than the iMac factory profile (which is ok).

Then I ran the DisplayCal software and here are the settings :

– Display: iMac Pro, Instrument: i1Display Pro, Mode: LCD (generic)
– White level drift compensation OFF, Black level drift compensation: OFF
– Override display update delay OFF, Override display settle time multiplier OFF
– Output levels : Auto
– Correction : LCD PFS Phosphor WLED IPS, 99% P3

– Interactive display Adjustment ON, update Calibration OFF
– Observer: CIE 1931 2°
– Whitepoint : color temperature 6500K reference (Daylicht)
– White level: Custom 120 cd/m2
-Black level: As measured
– Tone Curve: Gamma 2.2 Relative, Black output offset: 100%
– Ambiant light level adjustment : OFF
– Black point correction: OFF
– Calibration speed:  LOW

– Profile Type : Single curve + matrix, Black point compensation
– Profile quality: high
– Testchart : Very large
– Patch sequence : Minimize display response delay

Here also, I got the settings from internet (corresponding to iMac Pro).
Afterwards, when asked I set my screen brightness to 120,03 cd/m2

Adter an hour and a half, the result was even a bit yellower and brighter than the one I got with i1PRofiler (which was already more yellow than expected). But if it is the way it should be, then fine.

The only thing that bugs me is that the two profiles are different enough for me not to know which one to rely on. The results are not extremely different but the difference is really there and choosing one over the other will have consequences when editing.

To me, if two calibration software give visually different results with standard settings, it defeats the purpose of calibration. The best case scenario is that one is an accurate profile and the other isn’t. Worst case scenario, none is. So, here I am back to square one.
Anything in the settings that justifies this? Any reason for me to go with one rather than the other?

One last but huge thing: here is what I get from DisplayCal after calibration:

“Profile Self deltaE*76: average 0.70, maximum 3.51, RMS 0.87

Gamut coverage:
100% sRGB
88.8% Adobe RGB
99.8% DCI P3

Gamut Volume :
153.3% sRGB
107% Adobe RGB
110% DCI P3″

The 88.8% of Adobe RGB seems bad. Is it ?
Does it mean my display is crap or not?
Anything I can do?
When is it a problem and when is it not?

Thanks helping me interpreting this all and telling me what to do so that my profile is something I can trust for the work I have to do (scan hundreds of illustrations, edit them and send them to a pro print shop, so I’d better be sure of what I’m doing before I start)

Happy new year !

• This topic was modified 3 years, 3 months ago by Bachir Messaouri.
• This topic was modified 3 years, 3 months ago by Bachir Messaouri.

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[Vincent]

Hi,

I have an iMac Pro and I used a I1Display Pro to calibrate and profile it.

I first used i1Profiler software and here are the settings I used:

– IMac
– GB-Led
– CIE D65
– Luminance: 120 cd/m2
– Gamma Standard 2.2
_ Contrast report: native
– No flare correct
– No native control of ambiant light
-Patch set  of 461 units
– ADC On
– RVB manual settings Off

Use the proper correction, WLED PFS. This should be equal to DisplayCAL CCSS “WLED PFS 95% P3” (VVX Panasonic… etc . csss)

[Bachir Messaouri]

Thanks.
I don’t get the relationship between the quote you made and your comment. Are you asking me to use this correction in the i1Profiler? I don’t seem to find anywhere there where I can set a correction.

If you are mentioning DisplayCal instead, I used this correction “LCD PFS Phosphor WLED IPS, 99% P3”.
If that is what I need to change, why would this one be better (I’m not skeptical, just asking)?
Because I’ve seen also many custom correction files for iMac Pro but as they are different one from another, it’s hard to know why to select one correction rather than another and why that one would be THE one.

Thanks for the clarifications.

PS: what about the 88.8% Adobe RGB Gamut coverage?
That’s a bad result? Anything I can do about that?

[Vincent]

Thanks.
I don’t get the relationship between the quote you made and your comment. Are you asking me to use this correction in the i1Profiler? I don’t seem to find anywhere there where I can set a correction.

Yes, i1Profiler. It should be a combo under screen icon.

Because I’ve seen also many custom correction files for iMac Pro but as they are different one from another, it’s hard to know why to select one correction rather than another and why that one would be THE one.

P3 macs, whatever they are macbooks or LG ultrafine or iMac are WLED PFS “exactly P3”, with are the bundled correction for WLED PFS P3 macs in DisplayCAL. This is “the one”.

I1Profiler has not it, it has other P3 PFS with less saturated green (95% P3). If you plot spectral power distribution od these two CCSS you’ll see.
Anyway it is close enough so if using i1Profiler use this one, or if you wish to compare aples vs apples result, use it in DisplayCAL too (but “the one” is the first one I said)

PS: what about the 88.8% Adobe RGB Gamut coverage?
That’s a bad result? Anything I can do about that?

It’s expected. They are just P3 display. Nothing more nothing less. Apple does not care at all about photographers or graphic arts.
Of the other side a new Eizo CG has 98%-99% of both AdobeRGB and P3. Red primary is “P3”, Green primary is “AdobeRGB” so they cover both worlds. It uses same WLED PFS technology for LED but green, again, is slightly modified to have more saturated coordinates (towards AdobeRGB green). Again if you plot spectral powerr distribution if this backlight (WLED PFS HP z24x G2 in DisplayCAL) you’ll see the difference.

There are 3 flavors of WLED PFS each one with slightly more saturated green than previous one. Apple aims their displays to become a new standard for “consumer” content, hence they aime for “exactly p3” displays so they can oversimplify a lot of color management calculations (and some of this simplifications are the source of color management issues with “complex ICC display profilles”, hance DisplayCAL default values to avoid it even if looseing a bit of accuracy: single curve + matrix profile, black point compensation).

[Vincent]

Thanks.
I don’t get the relationship between the quote you made and your comment. Are you asking me to use this correction in the i1Profiler? I don’t seem to find anywhere there where I can set a correction.

I1profiler (v3.3.0 & Big Sur Intel) main screen, choose “Advanced” (right) then “profile” (left menu)

1st “page”, display setup. Under your display icon choose “PFS phosphor” (WLED PFS 95% P3 in DIsplayCAL, they are exactly the same)

GBLED are NEC PA272W, PA242W, Dell U2413.. etc, not yours. Again if you plot spectral power distribution of U2413 CCSS bundled with displayCAL you can see it by yourself. GBLED is previous generation (2014) photography monitors backlight, covering full-almost full AdobeRGB and near 94% P3, Red primary is slight less saturated than P3 red. Again GBLED tries to cover both worlds (AdobeRGB vs P3) and beyond (large % of eciRGBv2, and significative amount of Prophoto)… they aim for photography & graphic arts needs, not for “casual consumer content” production & consumption like Apple ecosystem does.

• This reply was modified 3 years, 3 months ago by Vincent.
• This reply was modified 3 years, 3 months ago by Vincent.
• This reply was modified 3 years, 3 months ago by Vincent.

[Bachir Messaouri]

Thanks a lot for the explanations. I’ll try this tomorrow or the day after (as soon as I can) and I’ll get back to you.
Thank you very much.

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