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Since I will be using the ‘XYZ LUT + Matrix’ profile type, I am assuming that I need to enable and configure the 3D LUT tab in DisplayCal? Would you happen to be able to recommend what settings I should use, if so? I have attached a screenshot with all of the options for reference.
NO.
A profile is just a description of a device’s behavior. It could be an ideal description, by RGB primaries coordinates + gamma, assuming perfectly additive behavior (matrix) or a mesh of points covering the whole color volume to capture irregular behavior (XYZLUT).
A LUT3D is a fixed, like crystal minerals, transformation between two colorspaces (profiles). ICC color managed apps do not need them to show some sRGB/AdoberGB image in display colorspace.
Some artist may pack a fixed transformation from sRGB to sRGB for example applying certain color edition for artistic purposes… but these LUT3Ds are between “standard” (or maybe just raw RGB colors) colorspaces not “color calibrations”. So Krita is not using that “LUT” for display calibration.
Video players may use LUT3D for calibration, to speed up reeconding of Rec709 content into display colorspace, but they won’t use ICCsOkay, I think I understand; thank you for the clarification.
Could I just inquire about the following settings before I proceed with the calibration?
1. You said that I will mostly be using a default configuration, but the ‘Settings’ configuration at the top of the DisplayCal window is set to ‘<Current>’ and I see that there is an option called ‘Default (Gamma 2.2),’ so I’m not sure which of these is the actual default option. Should I be using ‘<Current>’ or ‘Default (Gamma 2.2)?’
2. Just to be sure, are ‘Whitepoint’ set to ‘Color Temperature’ at 6500 K, ‘Calibration Speed’ set to medium, and ‘Amount of Patches’ set to 175 all correct?
So, just to confirm, the DisplayCal settings that I previously shared are all correct? Including the patch number of 175 and medium calibration speed?
IDNK which profile type you are using. If you enable advance in options you’ll see them.
Matrix = well behaved displays, good additive only behavior, display can be predicted by gamma and RGB primaries
XYZLUT = 3d mesh profile to capture innacuraces.
Most CMM like just matrix. IDNK GIMP or other Linux editing software.Same answer
Oh, are you asking what ‘Profile Type’ is set to? The default appears as ‘XYZ LUT + Matrix,’ so I thought that was what I was supposed to be using because you didn’t indicate otherwise when I asked about it previously. If this is indeed the right profile type for my situation, could you please let me know then if the ‘Settings’ configuration near the top of the DisplayCal window should be on ‘<Current>’ or ‘Default (Gamma 2.2),’ and if ‘Whitepoint’ set to ‘Color Temperature’ at 6500 K, ‘Calibration Speed’ set to medium, and ‘Amount of Patches’ set to 175 are all correct?
Also, I feel I must apologize if it seems like we’re going in circles at times. Being completely new to the workings of DisplayCal (and calibration, as you know), I sometimes struggle to make connections and understand some of the more complex information. So I really appreciate your patience and continued guidance as I learn.
if you actually need an XYZLUT profile, yes, that testchart for lut profiles is a cube ~5 per edge, it will be the minimum.
XYZLUT = 3d mesh capturing display XYZ coord per RGB triplet conbination, so 175 = ~5 nodes per edge + additional grayscale tracking.
As you can see is the minimum… and it rises by cubic power. 10 nodes->1000 patches, 17 nodes -> 5000 patches and so on.
300 -400 patch selection is about ~7 nodes per edgeIDNK how bad is your display. VCGT grey calibration can be re utilized for other profiles if display was so bad behaved that you get high errors with 175 patches XYZLUT.
Given that my laptop’s display is very old, it might be better if I use the ‘XYZ LUT + Matrix’ profile type, as there may be non-linear color inaccuracies that need correcting. So, am I right in thinking that I should try this profile type with 175 patches, and if my display does not produce ‘well-behaved’ results, then I might need to do another calibration with more patches?
Also, you had said not to configure the 3D LUT tab in DisplayCal, but will XYZ LUT information still be generated for my display even with the 3D LUT tab deactivated?
Lastly, I plan to install the profile that DisplayCal creates and then enable the ‘Use system monitor profile’ option in Krita. In order to test if the profile is working, do I just follow the instructions you previously provided, or is there another method I should use?
I do no not think age has much to do with color inaccuracies. It probably dies a lot of blue 1st. Look at 5% blue and see if its there. It was faded on my old screen. It depends on the hours on the screen and the wear and tear on the screen with max brightness on. If it looks decent to eyes it is good. Still you would XYZ lut +matrix. It will only fix color managed apps. XYZ lut and a matrix profile look about the same. Matrix might be better even. You have to compare. Fixing color in the lowend with xyz lut in a non linear display takes a really big patch. But your screen maybe fine 90% of it without a ton of patches. The patches will help but it will be hard to get a calibration. It will have to strech the low level color that is to low to it highest intensity which is close to correct. The other colors with good low level will stretch the same but be compressed. Simple is better. It is a opinion which is the best.
I just thought Lagom LCD test would be good to check if blue was broken. On contrast you should see 2 a little of 1 and positive 4. I could only see 5 and up on my old and people still thought it was good. I did the best I could with white balance and getting all the rest right and compromising to get blue a little better. http://www.lagom.nl/lcd-test/contrast.php . I wish it was a secure link.
Given that my laptop’s display is very old, it might be better if I use the ‘XYZ LUT + Matrix’ profile type, as there may be non-linear color inaccuracies that need correcting. So, am I right in thinking that I should try this profile type with 175 patches, and if my display does not produce ‘well-behaved’ results, then I might need to do another calibration with more patches?
OK
Also, you had said not to configure the 3D LUT tab in DisplayCal, but will XYZ LUT information still be generated for my display even with the 3D LUT tab deactivated?
3DLUT = mapping form one profile to another
XYZLUT Profile : 3d mesh description of display.
Hence, yes. I’ve explained this several times, IDNK if it was in this thread or another last week
Lastly, I plan to install the profile that DisplayCal creates and then enable the ‘Use system monitor profile’ option in Krita. In order to test if the profile is working, do I just follow the instructions you previously provided, or is there another method I should use?
IDNK how Krita behaves. Seems OK. It’s easier to test if an app A is color managing properly than on a lesss than sRGB display, because on a widegamut if you try to paint 255 sRGB green it would be visually edident that something is wrong. I’m not sure to visually test Krita’s without using spotread commandline. Sorry.
Thank you for your input, Ben, and the useful link.
Interestingly enough, I am actually able to make out all of the blue values (dark included) on the ‘Contrast’ page of the Lagom LCD website with my non-calibrated screen. In fact, the colors of my screen are a little too blue. But with the DisplayCal profile that I just created yesterday (using the ‘XYZ LUT + Matrix’ profile, medium calibration speed, and 175 patches, among other settings), the ‘1’ blue is practically indistinguishable from the background, and the ‘2’ and ‘3’ blues are only slightly visible. I’m not sure what this indicates.
I have posted the results of my first calibration in a response to Vincent below. Do you have any thoughts on them?
Okay, I completed the first calibration. Thank you very much for all of your help with getting me to this point.
Based on the results (see attached image below and the profile information images here: https://imgur.com/a/CnliJ4v), do you think I should try re-calibrating with different settings, or is it okay if I proceed with attempting to test the calibration using ‘spotread’?
Also, after the profile was installed, a message popped up saying ‘The profile has been installed, but there may be problems,’ with a green check mark next to ‘ArgyllCMS: OK’ and ‘Profile Loader: OK’ and a red X next to ‘colord:gi.repository.GLib.Error: GLib.Error(‘GDBus.Error:org.freedesktop.ColorManager.NotFound: profile id ‘icc-d4e1b506513a6672bc8e659463ca30a6′ does not exist’, ‘g-io-error-quark’, 36).’ Would you happen to know what this means and if I need to do anything about it?
Thank you for your input, Ben, and the useful link.
Interestingly enough, I am actually able to make out all of the blue values (dark included) on the ‘Contrast’ page of the Lagom LCD website with my non-calibrated screen. I
Lagom test are menat to be seen non color managed. Maybe Midori browser or something like that.
Regarding the CIE a*b* plot looks like a small gamut office laptop: fix wp, choose perceptual intent on krita to avoid OoG clipping and little more you can do.
Thanks for doing a visual check. Especially no non pro laptop screen is perfect. Any color could be going out but it is not. That is good. It is normal to be barely perceptual. The other non xyz lut might give a better than 8 max DE in the finish report but you will not be able to make a 3d lut to use. You can get everything right without 3d lut and then can do 3d lut later. With a 8 de error somewhere you might see it. Less likely with a 5 de. There is many combos of red green and blue that look alike. I have had 15de errors and I think a 3de error once. I mess with screen settings a lot.
I do not know the error. I recommend looking for the file it is not finding. I think it could be a permission error. Check the desktop color manager in the os. It could be not useing the display cal profile. The name does not look like a displaycal profile.
So, when I viewed the Lagom test with no calibration applied (just my screen’s default colors), was I doing so in a non-color managed environment?
When you say to fix whitepoint, do you mean that I should choose a different setting for it in DisplayCal other than ‘Color Temperature’ set to 6500 K? And should I try increasing the patch amount? If so, could you suggest what might be good values to change these two settings to?
Also, do you think a matrix profile with no XYZ LUT might result in less errors, like Ben mentioned?
Lastly, I thought that the ‘Relative Colorimetric’ rendering intent was the best to use for the most accurate representation of colors (especially for professional digital art use), so wouldn’t it be better than ‘Perceptual’ (which compresses all colors)?
I see. So you think I should try a matrix-only profile, as this could potentially result in lower DEs? If so, which of the following options might be best to use: ‘Curves + Matrix,’ ‘Single Curve + Matrix,’ ‘Gamma + Matrix,’ or ‘Single Gamma + Matrix’? And do you think I should use more than 175 patches?
If matrix-only doesn’t work out though, then were you saying to go back to the ‘XYZ LUT + Matrix’ profile?
According to some information I found, I think the ICC profile mentioned in the error message is an internal identifier assigned by my system to the DisplayCal profile. I wasn’t able to find it in my system’s file browser, but when I installed the DisplayCal profile, my screen’s colors instantly changed, and the DisplayCal profile is selected for my display in my OS’ color management software. Do you think, therefore, that I need to worry about the error message since it seems my system is using the DisplayCal profile?
