[GH-ISSUE #1714] Dragging brightness slider to 100% yields monitor brightness of 95% Dell U3223QE #951

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opened 2026-05-05 06:55:26 -06:00 by gitea-mirror · 2 comments

gitea-mirror commented

2026-05-05 06:55:26 -06:00

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Originally created by @adamshackleford on GitHub (Jan 3, 2025).
Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/1714

Before opening the issue, have you...?

Searched for existing issues
Looked through the wiki
Updated MonitorControl to the latest version (if applicable)

Describe the bug

When I drag MonitorControl's brightness slider to 100% the monitor's hardware brightness is actually only 95% (for example, point being it's < 100%).

Monitor is a Dell U3223QE; MonitorControl is 4.2.0 (build 7048); macOS is 12.7.6 (21H1320); running on a 2021 M1 Max MacBook Pro 16". Have another Dell, a U3219Q, that appears to be unaffected.

This behavior is repeatable. Drag the slider back and forth a few times, and finally drag it all the way to the right.

"Reset Preferences" in MonitorControl preferences does not help.

Steps to reproduce

Drag the brightness slider back and forth a few times
Finally drag it all the way to the right
Check hardware brightness via the monitor's on-screen-display. It's < 100%

Expected behavior

Hardware brightness via the monitor's on-screen-display is 100%

Anything else?

Environment Information (please complete the following information)

- macOS version: 12.7.6 (21H1320)
- Mac model: 2021 M1 Max MacBook Pro 16"
- MonitorControl version: 4.2.0 (build 7048)
- Monitor(s): Dell U3223QE (has the issue), Dell U3219Q (doesn't appear to have the issue)
- Apple Silicon/M1 (yes or no): yes

Originally created by @adamshackleford on GitHub (Jan 3, 2025). Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/1714 ### Before opening the issue, have you...? - [X] Searched for existing issues - [X] Looked through [the wiki](https://github.com/MonitorControl/MonitorControl/wiki) - [X] Updated MonitorControl to the latest version (if applicable) ### Describe the bug When I drag MonitorControl's brightness slider to 100% the monitor's hardware brightness is actually only 95% (for example, point being it's < 100%). Monitor is a Dell U3223QE; MonitorControl is 4.2.0 (build 7048); macOS is 12.7.6 (21H1320); running on a 2021 M1 Max MacBook Pro 16". Have another Dell, a U3219Q, that appears to be unaffected. This behavior is repeatable. Drag the slider back and forth a few times, and finally drag it all the way to the right. "Reset Preferences" in MonitorControl preferences does not help. ### Steps to reproduce 1. Drag the brightness slider back and forth a few times 2. Finally drag it all the way to the right 3. Check hardware brightness via the monitor's on-screen-display. It's < 100% ### Expected behavior Hardware brightness via the monitor's on-screen-display is 100% ### Anything else? <img width="282" alt="Screen Shot 2025-01-03 at 01 09 26 PM" src="https://github.com/user-attachments/assets/e6fe665b-bd85-48a7-8692-b93bf7868227" /> ### Environment Information (please complete the following information) ```markdown - macOS version: 12.7.6 (21H1320) - Mac model: 2021 M1 Max MacBook Pro 16" - MonitorControl version: 4.2.0 (build 7048) - Monitor(s): Dell U3223QE (has the issue), Dell U3219Q (doesn't appear to have the issue) - Apple Silicon/M1 (yes or no): yes ```

gitea-mirror closed this issue

2026-05-05 06:55:27 -06:00

gitea-mirror commented

2026-05-05 06:55:31 -06:00

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@adamshackleford commented on GitHub (Jan 3, 2025):

@adamshackleford commented on GitHub (Jan 3, 2025): ![IMG_0005](https://github.com/user-attachments/assets/a0a8f95f-fa02-49c3-ae9f-8f547b5a3145)

gitea-mirror commented

2026-05-05 06:55:33 -06:00

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Owner

@waydabber commented on GitHub (Jan 3, 2025):

It might be possible that the display uses a different range than the usual 0-100 for DDC. You can configure this under advanced settings.

You can check out the auto configuration report in BetterDisplay as well, maybe that gives some info on this.

Make sure you are using a neutral display preset if the display supports such.

@waydabber commented on GitHub (Jan 3, 2025): It might be possible that the display uses a different range than the usual 0-100 for DDC. You can configure this under advanced settings. You can check out the auto configuration report in BetterDisplay as well, maybe that gives some info on this. Make sure you are using a neutral display preset if the display supports such.