[GH-ISSUE #1446] Screenshots come up blank when brightness dimmed #822

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opened 2026-05-05 06:44:54 -06:00 by gitea-mirror · 1 comment

gitea-mirror commented

2026-05-05 06:44:54 -06:00

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Originally created by @fxerkan on GitHub (Oct 9, 2023).
Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/1446

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

Hi,
I'm using Macbook Air 2020 M1 chipset with 2 Extended Displays (Dell S2721QS & Dell P2719H) via a Dock station (plugable displaylink) so that there is no brightness adjustment option.

Because of that I installed MotionControl 4.2.0 app to control the extended displays brightness at software level dimming and hardware level not available at my monitors.

When I set the brightness level %100 there is no issue, I can take screenshots with any of these applications at any displays.

Apple's own screenshot functionality ( cmd+shift+ 4 or 5 )
Parallels Toolbox Screen Capture
Lightshot screenshot ( cmd+shift+s )

But, when I decreased the brightness under the %100 like %90, %80, %70.. and try to take a screenshot at any extended display - all the screenshots seems blank or black only color.

If i set the brightness again at %100 everything works as expected.

Steps to reproduce

use an extended display which does not support hardware dimming
decrease the brightness %90 or %75
try to take a screenshot at the extended display with one of these tools (Apple's own screenshot functionality , Parallels Toolbox Screen Capture, Lightshot screenshot
check the saved screenshot is blank/black

Expected behavior

saved screenshot should be like this, not blank or black only
100 Brightness Screenshot

Anything else?

Issue %90 brightness-Apples Screenshot as you can see its a blank image

%90 brightness-Parallels Toolbox Capture Screen

%90 brightness-Lightshot

Environment Information (please complete the following information)

- macOS version: Sonoma 14.0 (23A344)
- Mac model: MacBook Air M1 2020
- MonitorControl version: 4.2.0 Build 7048
- Monitor(s): Dell S2721QS and Dell P2719H
- Apple Silicon/M1 (yes or no): yes

Originally created by @fxerkan on GitHub (Oct 9, 2023). Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/1446 ### 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 Hi, I'm using Macbook Air 2020 M1 chipset with 2 Extended Displays (Dell S2721QS & Dell P2719H) via a Dock station (plugable displaylink) so that there is no brightness adjustment option. Because of that I installed MotionControl 4.2.0 app to control the extended displays brightness at software level dimming and hardware level not available at my monitors. When I set the brightness level %100 there is no issue, I can take screenshots with any of these applications at any displays. * Apple's own screenshot functionality ( cmd+shift+ 4 or 5 ) * Parallels Toolbox Screen Capture * Lightshot screenshot ( cmd+shift+s ) But, when I decreased the brightness under the %100 like %90, %80, %70.. and try to take a screenshot at any extended display - all the screenshots seems blank or black only color. If i set the brightness again at %100 everything works as expected. ### Steps to reproduce 1. use an extended display which does not support hardware dimming 2. decrease the brightness %90 or %75 3. try to take a screenshot at the extended display with one of these tools (Apple's own screenshot functionality , Parallels Toolbox Screen Capture, Lightshot screenshot 4. check the saved screenshot is blank/black 5. ### Expected behavior saved screenshot should be like this, not blank or black only <img width="1280" alt="100 Brightness Screenshot" src="https://github.com/MonitorControl/MonitorControl/assets/20793273/39f49e26-277e-48f2-ae78-2dda2ab39b39"> ### Anything else? Issue %90 brightness-Apples Screenshot as you can see its a blank image <img width="2560" alt="90 brightness-Apples Screenshot" src="https://github.com/MonitorControl/MonitorControl/assets/20793273/9545a7db-c22a-4e99-9d46-6c766197cdc9"> %90 brightness-Parallels Toolbox Capture Screen <img width="640" alt="90 brightness-Parallels Toolbox Capture Screen" src="https://github.com/MonitorControl/MonitorControl/assets/20793273/67191e00-50b2-4cfa-89af-87f060f265fe"> %90 brightness-Lightshot <img width="640" alt="90 brightness-Lightshot" src="https://github.com/MonitorControl/MonitorControl/assets/20793273/a9c3692f-af1c-445a-8f12-785cec12f478"> ### Environment Information (please complete the following information) ```markdown - macOS version: Sonoma 14.0 (23A344) - Mac model: MacBook Air M1 2020 - MonitorControl version: 4.2.0 Build 7048 - Monitor(s): Dell S2721QS and Dell P2719H - Apple Silicon/M1 (yes or no): yes ```

gitea-mirror closed this issue

2026-05-05 06:44:55 -06:00

gitea-mirror commented

2026-05-05 06:44:59 -06:00

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@waydabber commented on GitHub (Oct 18, 2023):

This happens if only software dimming is applied and gamma table manipulation is disabled in the app. In this case a black overlay is used with changing transparency as a last resort - the screenshot app captures this black overlay.

@waydabber commented on GitHub (Oct 18, 2023): This happens if only software dimming is applied and gamma table manipulation is disabled in the app. In this case a black overlay is used with changing transparency as a last resort - the screenshot app captures this black overlay.