How to adjust gamma alone?

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This topic contains 29 replies, has 3 voices, and was last updated by  Florian Höch (@fhoech) 2 years, 6 months ago.

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  • #6557

    Monstieur (@monstieur)
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    I currently use Windows Display Calibration and adjust the gamma slider to compensate for my monitor’s low gamma. Windows creates a new profile (based on the default sRGB profile) that applies my gamma settings. The problem is the GPU gamma ramp keeps getting reset by fullscreen games etc.
    Instead, I want to use DisplayCAL Profile Loader to load my profile and automatically reload the GPU gamma ramp. The problem is, when I select the profile Windows created, it doesn’t apply gamma. i.e. the screen remains at its original gamma. It appears that the gamma slider setting is not part of the ICC profile.
    How do I create a profile in DisplayCAL that is based on the default sRGB profile, with the equivalent of adjusting the gamma slider in Windows Display Calibration? I do not want to colour calibrate with a colorimeter. I just want to adjust the gamma.

    #6566

    Florian Höch (@fhoech)
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    Windows Display Calibration unfortunately doesn’t include a ‘vcgt’ tag in the profiles it creates, so the embedded calibration only works with Windows’ own calibration feature. If you attach the profile, I can convert the profile for you (I’ll probably add automatic parsing of the MS-specific parts in the next version, as it’s trivial to do).

    #6568

    Monstieur (@monstieur)
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    I’ll attach the profile when I get back home.

    Is it not possible to simply do gamma adjustment in DisplayCAL itself with an automatically generated profile based on sRGB or from the EDID or whatever?

    #6572

    Florian Höch (@fhoech)
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    Is it not possible to simply do gamma adjustment in DisplayCAL itself with an automatically generated profile based on sRGB or from the EDID or whatever?

    No, that is not accurate color management. The latter always requires actual measurements.

    #6575

    Monstieur (@monstieur)
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    I do have a Spyder 4 Elite, but even after calibration with the Spyder software the gamma is too bright. And the calibration itself has a very negligible colour difference in the before and after screens, since my monitor (PG278Q) seems to be accurate to sRGB out of the box (whatever that means, given that the gamma is visibly off). What is the Windows Display Calibration doing by simply adjusting the gamma slider on the sRGB profile? How is it preserving the sRGB colours while changing the gamma?

    I’ve attached the Windows generated profile with the adjusted gamma here.

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    #6578

    Florian Höch (@fhoech)
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    I do have a Spyder 4 Elite, but even after calibration with the Spyder software the gamma is too bright.

    Note that how something looks on a monitor with TN panel is highly dependent on viewing angle (TN panels are not recommended for color critical work for this reason among others).

    What is the Windows Display Calibration doing by simply adjusting the gamma slider on the sRGB profile?

    The profile itself will still be the standard sRGB profile.

    Attached is the modified profile, where I have converted the embedded calibration to the more commonly used ‘vcgt’ format.

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    #6585

    Monstieur (@monstieur)
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    Thanks for the profile. The gamma is set by DisplayCAL initially, but it does not reload when it’s reset by a full screen application. When I click the “Load calibration from current display device profile(s)” menu item, it says loaded and the counter increases, but the gamma does not change. It only gets changed if I click “Reset video card gamma table” first. I assume this is some kind of bug.

    How long do I have to wait after entering a fullscreen application for the gamma to be changed automatically? Does it have to be a timer or is there some way for DisplayCAL profile loader to detect fullscreen application launches and reload the profile automatically?

    • This reply was modified 2 years, 7 months ago by  Monstieur.
    #6589

    Florian Höch (@fhoech)
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    When I click the “Load calibration from current display device profile(s)” menu item, it says loaded and the counter increases, but the gamma does not change. It only gets changed if I click “Reset video card gamma table” first.

    Check in Windows color management settings under advanced settings if Windows display calibration is enabled. If so, disable it. Do you have the Windows 10 creators update installed?

    How long do I have to wait after entering a fullscreen application for the gamma to be changed automatically?

    Calibration is reloaded every three seconds. The profile loader cannot change gamma for fullscreen apps if they use Direct3D APIs.

    #6590

    Monstieur (@monstieur)
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    Check in Windows color management settings under advanced settings if Windows display calibration is enabled. If so, disable it.

    Windows calibration is disabled and the “Preserve calibration state” option is enabled in DisplayCAL. The correct profile is associated.

    Do you have the Windows 10 creators update installed?

    Yes, this problem started after the Creators Update. I play Dota 2 which has a -nogammaramp parameter which disables the in-game brightness controls and preserves the desktop colour profile. This option stopped working after the Creators Update. It resets the gamma table even though the in-game brightness settings are still disabled with the parameter.

    Calibration is reloaded every three seconds. The profile loader cannot change gamma for fullscreen apps if they use Direct3D APIs.

    The Spyder 4 software seemed to be able to work in fullscreen games. After I launched a game and waited a few seconds, the colours would visibly change as the profile was reloaded. I am no longer using the Spyder software though since all I need is gamma adjustment.

    However DisplayCAL does not reload the profile even after I quit the game and return to the desktop.

    • This reply was modified 2 years, 7 months ago by  Monstieur.
    • This reply was modified 2 years, 7 months ago by  Monstieur.
    • This reply was modified 2 years, 7 months ago by  Monstieur.
    #6594

    Florian Höch (@fhoech)
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    The Spyder 4 software seemed to be able to work in fullscreen games. After I launched a game and waited a few seconds, the colours would visibly change as the profile was reloaded.

    But only if the game doesn’t use Direct3D APIs. The Direct3D API restricts gamma changes to the fullscreen process, no outside processes can interfere.

    #6595

    Monstieur (@monstieur)
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    But only if the game doesn’t use Direct3D APIs. The Direct3D API restricts gamma changes to the fullscreen process, no outside processes can interfere.

    But it’s not reloading on the desktop either after quitting a game. I need to click “Reset” manually first and then “Load calibration” again.

    • This reply was modified 2 years, 7 months ago by  Monstieur.
    #6597

    Florian Höch (@fhoech)
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    What type of graphics card are you using? Intel by any chance?

    #6598

    Monstieur (@monstieur)
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    GTX 1080 SLI, with the latest WHQL drivers.
    Since the Creators Update, even the Windows calibration does not reload after quitting a game. Clicking the “Reload current calibrations” button does not do anything. I must remove the profile and add it again for the gamma table to be reloaded. This started only after the Creators Update.

    • This reply was modified 2 years, 7 months ago by  Monstieur.
    • This reply was modified 2 years, 7 months ago by  Monstieur.
    #6609

    Florian Höch (@fhoech)
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    Since the Creators Update, even the Windows calibration does not reload after quitting a game. Clicking the “Reload current calibrations” button does not do anything.

    That’s not ideal but somewhat relieving, because that makes it less likely to be a bug in the DisplayCAL profile loader.

    Try this: Close the DisplayCAL profile loader, then open its config file (%APPDATA%\Roaming\DisplayCAL\DisplayCAL-apply-profiles.ini) in a plain text editor (i.e. Notepad). Add a line profile_loader.buggy_video_drivers = nvidia (I’m assuming the nVidia card shows up in device manager as “NVIDIA GeForce GTX 1080”, if not, pick another keyword from the driver string, case does not matter). This will enable the videoLUT loading hack that’s normally only active for Intel. Save and close the config file, then start the profile loader. Does it help? You should see a message “Buggy video driver detected: NVIDIA GeForce GTX 1080.” in the profile loader logfile (%APPDATA%\Roaming\DisplayCAL\logs\DisplayCAL-apply-profiles.log), confirming that the videoLUT loading hack is active.

    #6612

    Monstieur (@monstieur)
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    It works, and even in D3D9EX fullscreen exclusive mode! After the game launches, within a few seconds the gamma changes in fullscreen too, and remains correct on the desktop after I quit. This is how the Spyder software used to work. I am not sure under which Direct3D fullscreen conditions the gamma *cannot* be overridden as you said.

    • This reply was modified 2 years, 7 months ago by  Monstieur.
    • This reply was modified 2 years, 7 months ago by  Monstieur.
    • This reply was modified 2 years, 7 months ago by  Monstieur.
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