SUMMARY When configuring an HDR display for the first time, the settings applet does not have the correct peak brightness in the HDR calibrator, as detected from the display EDID, unless the display is left off HDR mode and the color profile is set to monitor built-in and applied first. Then it will have the HDR peak brightness correctly read from the monitor. STEPS TO REPRODUCE 1. Attach an HDR monitor. (in this case, an Asus XG27UCS) 2. Configure the display to HDR mode. OBSERVED RESULT The display in HDR calibrator will not have a properly read peak brightness level from the EDID. EXPECTED RESULT The display should read the initial peak brightness level from the EDID. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Arch Linux KDE Plasma Version: 6.4.3 KDE Frameworks Version: 6.16.0 Qt Version: 6.9.1 ADDITIONAL INFORMATION I was able to somehow make the settings panel absorb my monitor's factory calibrated peak brightness level of 486 nits, by setting the monitor to SDR again, then setting the ICC profile to monitor built-in and applying. Then when I enabled HDR, the peak brightness was correctly set.
I can't replicate that here, the default value matches the one from the EDID. Please remove the peak brightness override from the calibration page (kscreen-doctor output.1.maxBrightnessOverride.disable) and then attach the output of kscreen-doctor -o here
I can't reproduce it any longer, so I'm going to mark this as such. ``` Output: 1 DP-1 d0a9f63f-3e58-4dca-b04d-58294a36774e enabled connected priority 1 DisplayPort replication source:0 Modes: 1:3840x2160@60! 2:3840x2160@160* 3:3840x2160@144 4:3840x2160@120 5:3840x2160@120 6:3840x2160@120 7:3840x2160@100 8:3840x2160@60 9:3840x2160@60 10:3840x2160@50 11:3840x2160@30 12:3840x2160@30 13:3840x2160@25 14:3840x2160@24 15:3840x2160@24 16:2560x1440@160 17:2560x1440@120 18:2560x1440@60 19:1920x1200@60 20:1920x1080@120 21:1920x1080@120 22:1920x1080@100 23:1920x1080@60 24:1920x1080@60 25:1920x1080@60 26:1920x1080@50 27:1920x1080@30 28:1920x1080@30 29:1920x1080@25 30:1920x1080@24 31:1920x1080@24 32:1600x1200@60 33:1680x1050@60 34:1280x1024@60 35:1440x900@60 36:1280x960@60 37:1280x800@60 38:1280x720@60 39:1280x720@60 40:1280x720@60 41:1280x720@50 42:1024x768@75 43:1024x768@60 44:800x600@75 45:800x600@60 46:720x576@50 47:720x576@50 48:720x480@60 49:720x480@60 50:720x480@60 51:720x480@60 52:640x480@75 53:640x480@60 54:640x480@60 55:640x480@60 56:1600x1200@160 57:1280x1024@160 58:1024x768@160 59:2560x1600@60 60:2560x1600@160 61:1920x1200@160 62:1280x800@160 63:3200x1800@60 64:3200x1800@160 65:2880x1620@60 66:2880x1620@160 67:1920x1080@160 68:1600x900@60 69:1600x900@160 70:1368x768@60 71:1368x768@160 72:1280x720@160 Geometry: 0,0 1920x1080 Scale: 2 Rotation: 1 Overscan: 0 Vrr: Automatic RgbRange: Automatic HDR: enabled SDR brightness: 203 nits SDR gamut wideness: 0% Peak brightness: 486 nits Max average brightness: 486 nits Min brightness: 0.0969 nits Wide Color Gamut: enabled ICC profile: none Color profile source: EDID Color power preference: prefer efficiency and performance Brightness control: supported, set to 100% and dimming to 100% DDC/CI: allowed Color resolution: automatic (10), range: [8; 16] bits per color Allow EDR: unsupported Output: 2 DP-2 edd03ce9-e04e-4b8a-b059-21bfc6db47aa enabled connected priority 2 DisplayPort replication source:0 Modes: 73:3840x2160@60*! 74:3840x2160@30 75:2560x1440@60 76:1920x1200@60 77:1920x1080@60 78:1920x1080@60 79:1920x1080@60 80:1600x1200@60 81:1680x1050@60 82:1600x900@60 83:1280x1024@60 84:1440x900@60 85:1280x800@60 86:1152x864@60 87:1280x720@60 88:1280x720@60 89:1280x720@60 90:1024x768@60 91:800x600@60 92:720x480@60 93:720x480@60 94:640x480@60 95:640x480@60 96:640x480@60 97:2560x1600@60 98:3200x1800@60 99:2880x1620@60 100:1368x768@60 Geometry: 1920,0 1920x1080 Scale: 2 Rotation: 1 Overscan: 0 Vrr: Automatic RgbRange: Automatic HDR: incapable Wide Color Gamut: incapable ICC profile: /home/chris/.config/color/icc/devices/display/LGUltraHD.icc Color profile source: ICC Color power preference: prefer efficiency and performance Brightness control: supported, set to 50% and dimming to 100% DDC/CI: allowed Color resolution: automatic (10), range: [8; 16] bits per color Allow EDR: unsupported ```