Reddish and greenish whites after calibration?

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  • #36159

    ns1208
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    Hi,

    I have a pixio px277 and an hp z24i that I am trying to match colors on. Even post calibration, white on the z24i will show up as slightly greenish, but the whites on the px277 will be a much more reddish white than expected. I’m using a colormunki display with these settings:

    Spectral LCD White LED for both monitors correction
    6500k color temperature
    210 cd/m white level
    Gamma 2.2 Tone Curve

    Are there any other settings I should change to try to get these displays to match? I can’t seem to get them anywhere close no matter what I do.

    Thanks!

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    #36168

    Vincent
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    PX277 is not a white led since manufacturer web says its a widegamut 120% sRGB. It may be a qled, a qled equivalent (nano ips cover over white led), some WLED with PFS phosphor or another fancy new LED backlight. Hard to say without an spectrophotometer reading. Try QLED TV CCSS correction as a 1st guess.

    • This reply was modified 3 weeks, 2 days ago by Vincent.
    #36201

    ns1208
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    PX277 is not a white led since manufacturer web says its a widegamut 120% sRGB. It may be a qled, a qled equivalent (nano ips cover over white led), some WLED with PFS phosphor or another fancy new LED backlight. Hard to say without an spectrophotometer reading. Try QLED TV CCSS correction as a 1st guess.

    I got a bit of time to try this out, and I went through a few different correction profiles and still couldn’t get anything different out of the monitor. Everything I seem to try doesn’t get close on either of the monitors. Also I may need to add that the PX277 that I bought isn’t one of the newer models, I got this one in 2018 it’s the very first PX277 that was released.

    I’ve tried both a colormunki display and an i1 display 2 that I found at work, and they both produce pretty much the same thing: reddish grays on the pixio, greenish grays on the HP. If it helps at all either i’m using the same color as discord’s dark mode to compare between the two.

    Thanks for your help.

    #36205

    MW
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    Greys shouldn’t be affected by a wrong backlit correction, at least not in a way that their hue changes. But it happens in some displays, profiling should have caught that though. You need to install your profile, or use a different app that’d color managed, or use a system wide solution like dwm_lut.

    • This reply was modified 2 weeks, 4 days ago by MW.
    #36207

    Antonio Marcheselli
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    I believe what you are experiencing may be caused by metamerism. If the screens have different spectrum, your instrument – even a more expensive one – will say they are matching in colour but your eyes are going to tell you otherwise.

    I found that pretty normal between different technologies, that is, CCFL vs LED or Xenon lamps versus laser in cinemas.

    DisplayCAL allows you to match the white visually – click on the “visual whitepoint editor” under calibration. There you can display white and tweak it manually until both monitors match. When they match, you can take a reading of your “new white” and then calibrate with that.

    #36211

    Vincent
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    Greys shouldn’t be affected by a wrong backlit correction, at least not in a way that their hue changes. But it happens in some displays, profiling should have caught that though.

    +1, profile verification, check gret range a*b* and measured greyscale values in a*b*.

    Usually lowering calibration speed to medoum or slow should handle it better.

    I believe what you are experiencing may be caused by metamerism. If the screens have different spectrum, your instrument – even a more expensive one – will say they are matching in colour but your eyes are going to tell you otherwise.

    Not if this happens on grey. A grey , a neutral grey on a display should have a spectral power distribution (SPD) close to a scaled down white SPD. If that grey shows RGB imbalance… it is not grey and it is measured as not grey.

    #36212

    Vincent
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    PX277 is not a white led since manufacturer web says its a widegamut 120% sRGB. It may be a qled, a qled equivalent (nano ips cover over white led), some WLED with PFS phosphor or another fancy new LED backlight. Hard to say without an spectrophotometer reading. Try QLED TV CCSS correction as a 1st guess.

    I got a bit of time to try this out, and I went through a few different correction profiles and still couldn’t get anything different out of the monitor. Everything I seem to try doesn’t get close on either of the monitors.

    Then maybe you are doing all wrong… and “no data”/”no configuration” supports my claim.

    #36213

    Antonio Marcheselli
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    I know for experience that the same white patch on a Xenon or Laser projector WILL look different from a colour perspective and I was explained that that was due to Metamerism. Even a laser source using slightly different wavelengths – commonly used with 6P laser system in cinema projectors – will generate a different white (and different colours of course). I had the same issue when trying to match a CCFL with an LED monitor – hence I believe Florian stepped in to explain the purpose of the visual whitepoint editor.

    I cannot comment further as my knowledge of colour science is limited but that is my experience in my professional field.

    #36214

    Vincent
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    I know for experience that the same white patch on a Xenon or Laser projector WILL look different from a colour perspective and I was explained that that was due to Metamerism. Even a laser source using slightly different wavelengths – commonly used with 6P laser system in cinema projectors – will generate a different white (and different colours of course). I had the same issue when trying to match a CCFL with an LED monitor – hence I believe Florian stepped in to explain the purpose of the visual whitepoint editor.

    I cannot comment further as my knowledge of colour science is limited but that is my experience in my professional field.

    The issues he has reported this last time are not related to what you claim as “metamerism”, actually it’s “metameric failure” (the opposite, if they matched tehy will me metamers).

    Why? Because he claims now that he have issues on grey. *G*R*E*Y*. Read MW message above. If white has a color but green has another one on the same RGB technology screen we have RGB imbalance and device will capture it (if you measure troublesome spot color).

    Another different thing is that all his reports maybe be a little misleading (without data and detailed results just very simple descriptions), saying first white mismatch issue (caused by wrong colorimeter correction or observer metameric failure and corrected in this last situation by white point editor & visual matching like you said) and then saying that the issues are in GREY, hence MW & myself recomendations of measuring calibrated display (measurement report with detaile greyscale) since this issue can be captured by device (and solved by taking more measurements on native uncalibrated gamma ramp: calibration speed parameter)

    #36215

    Antonio Marcheselli
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    Thanks for correcting me on the terms used – I wasn’t aware. No need for capitals though! 🙂

    So what you are saying is that grey (or G*R*E*Y*) is supposed to match on ANY screen or projector regardless of the light source when the display is correctly calibrated/profiled? Not questioning what you say, just trying to understand.

    #36217

    Vincent
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    No, you did not understand at all my message.

    I’m saying that AFTER calibration grey must match the color of ITS OWN white on a RGB display because that grey, if neutral, will have a scaled down spectral power distribution of white’s + some background noise that is more relevant near black greys. If that grey has not the same color as white (and we are up enough on grayscale so light leakage on black is not relevant) that means RGB imbalance. RGB imbalance means “peaks” in spectral power distribution have a different balance/relative height in that grey that in white.
    A colorimeter can measure it, even without correction… just happens that without correction whire coordinates will be wrong and grey too but on the same expected offset if grey is neutral to his white.

    Thats what he is reporting now, you answered to 1st message (white mismatch on 2 screens). That is the reason of my last paragraph on previous message.

    • This reply was modified 2 weeks, 4 days ago by Vincent. Reason: typo
    #36219

    Antonio Marcheselli
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    Compared to its own white of course. Grey scale should be consistent of course.

    However, the way I read the OP message is that they are comparing the grey of one monitor with the grey of the other one. Hence my messages! 🙂

    If they are comparing different shades of grey on the same monitor, then of course something did not work as that should not happen.

    #36220

    ns1208
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    Compared to its own white of course. Grey scale should be consistent of course.

    However, the way I read the OP message is that they are comparing the grey of one monitor with the grey of the other one. Hence my messages! 🙂

    If they are comparing different shades of grey on the same monitor, then of course something did not work as that should not happen.

    Hi all, apologies I haven’t been including enough info. I attached both of the most recent profiles I made, and for a bit more info I’m not getting a consistent white point, which leads to all the other colors looking off. I can’t really tell to be completely honest.

    Whites on both of my monitors, as well as grays, both have tints of red/green on them respectively. I’m sure it’s possible I’m doing something completely wrong as well, but I followed this guide initially. I’m still not completely sure either what correction profile I should be using for my specific PX277 since it’s not on displayspecificiations.com, but online I found that the panel in my specific monitor is identical to Acer XB271HU, so I should be using w-led for my correction? Regardless though, the issue is the same no matter what correction I use.

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    #36223

    Antonio Marcheselli
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    ns1208

    Can you confirm that when you say that your white and grey have red/green tints you mean that when you put your monitors side by side and display a greyscale, the whole greyscale looks reddish on a monitor and greenish on the other?

    Thank you! 🙂

    #36224

    ns1208
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    ns1208
    Can you confirm that when you say that your white and grey have red/green tints you mean that when you put your monitors side by side and display a greyscale, the whole greyscale looks reddish on a monitor and greenish on the other?
    Thank you! 🙂

    Yes that’s exactly what happens.

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