Color profiles, Mac and monitors: me rend fou!

[Matteo]

Hi all.
 
First, sorry if I write in English! Hope is allowed in the forum. 
I was looking for a forum on darktable, and there are not that many. And I really need your help. 

My problem is with color management and darktable. 

I have a iMac (2013), with an external monitor, Eizo, AdobeRGB gamut, calibrated via internal monitor's software, via i1Pro. 

Now, I read here and here that darktable+OSX is unable to reproduce RGB Colors, it automatically clips to sRGB, no matter what color profile you choose. 

I managed to make darktable read my calibrated Eizo .icc profile, creating a folder inside darktable .config - color/out. 

Now, people tell me that I should not use that profile, since DT converts to sRGB, so what I do may create a mess. 

I want to know, given my equipment, which setting should I use to optimise color management. Shall I then select sRGB? or RGB? or my own .icc profile?  

You may answer in Frech, I perfectly understand 

Merci bien a tous!


upload images

[jpg54]

Effectivement, tu es sur un forum français, je suis passer par un traducteur en ligne pour lire ton post et il serait intéressant que tu passes ton message par un traducteur pour les mettre sur le forum pour que tu ais le plus de lecture.
J'allais te dire que tu peux faire une demande sur https://discuss.pixls.us/c/software/darktable mais j'ai vu que tu as déjà regardé sur ce site. Pour ton problème, je ne peux pas t'aider car j'utilise darktable sous Linux et Windows sur portable et je n'ai pas d'écran externe Eizo.

[Matteo]

Merci bien jpg54!!

Je l'afficherai de nouveau en français.

Merci

[pascal]

Is you Eizo monitor hardware calibrated?

[Matteo]

Is you Eizo monitor hardware calibrated?

Yes it is. 
This monitor has internal calibration software (ColorNavigation software comes within the monitor - model - ColorEdge CS2420).  
I use i1ProDisplay as colorimeter. 

From what I have been reading up to now, I am stuck to sRGB, no matter what I try to do. It has to do with Cairo, OSX and API (they tell me..I have no clue on those). 

That is to say, sRGB is the safest way to work, given that although darktable reads my .icc profile it does more harm than good. Output on the screen is always sRGB. Again, they tell me. 

But then, if so, I don't understand why I DO see a clear difference on my monitor when switching from sRGB to AdobeRGB. 

Sigh.
Thanks!!

[pascal]

First of all I know next to nothing about MacOS. For your monitor, as it is hardware calibrated and 99% of AdobeRGB I would use AdobeRGB as monitor profil in dt. Now if the cairo port only support sRGB that's too bad, but at least dt and your monitor would agree on the profile to use. And cairo will do whatever he can to display the actual color (that is, either shrinking the color space to sRGB or keep AdobeRGB or whatever in between). If you do see a difference, it may be that cairo is not so broken or maybe only the soft profile in dt won't be properly used. But in your case you have an hardware calibrated monitor, so it may be a different story. Hope this helps!

[pascalG]

Hello
I do not have mac anymore and can not check what I'm going to say anymore.
But the real thing of hardware calibration is that the profile is in the Lut's screen and not in the graphic card whose vgct must be linear.
In my opinion, it should be enough to indicate to "system" as screen profile into dt and let Eizo's Lut apply its own profile.
You should see the difference ...
It would be a shame to have this screen and stay in sRGB!

By the way, I read quickly the discussion on pixelus. Your profile is necessarily different from the Adobe RGB and may actually be a little bit higher. What is certain is that the Adobe RGB is a color workspace and can never integrate the specifics of a screen. That's why your profile will always be better.
Trust Elle Stone, it's the best color specialist and I'm glad she's speaking on this forum.

[pascal]

> to indicate to "system"

Not sure, "system" depends on what the system as recorded as as profile for the monitor. Better to use AdobeRGB which is what the Eizo monitor supports.

[pascalG]

Better to use AdobeRGB which is what the Eizo monitor supports

No, A98 is not a screen profile. We can not say enough that a color workspace is a reference system while a screen profile describes the colorimetric response of the material with its own defects, what color workspace obviously can't do. 
At worst, tell dt the profile of the screen, but I can't verify, I don't have the necessary configuration.

[pascal]

I don't think we are talking about the same thing. The Eizo is hardware profiled and the color space for this Eizo is AdobeRGB. So obviously that is the color space you need to use for the display profile. It will restrict the gammut to AdobeRGB, send the data to the monitor which *is* profiled and can render 99% of AdobeRGB color space.

So I still think it is better to use AdobeRGB instead of "system". This "system" profile is whatever the MacOS has for this screen. If it has selected AdobeRGB or nothing all is fine with system. If something else is selected it may not work. That's my point, better stay on the safe side as we do not know what the OS system profile is.

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> screen profile describes the colorimetric response of the material with its own defects, what color workspace obviously can't do.

I agree with this point. And that is exactly why to choose AdobeRGB to not do any colorimetric correction as the screen is hardware calibrated.