I have an iMac27 run Lion, now I buy a cinema display 27, but at display setting only main screen have brightness adjust controller. And use keyboard to adjust screen brightness also only change main screen.

can not find how to control cinema display brightness

5 Answers 5


It's way simpler than that guys. The brightness on the display is controlled by simply pressing:

Control+F1 OR Control+F2 to adjust brightness on your secondary screen (the one without the menubar).

F1 and F2 to adjust brighness on your main screen (the one on which the menubar is located).

If you have adjusted settings in System Preferences for the Function Keys to behave as standard Function keys, you will need to hold the Fn key in addition to each combination too.

If your Cinema display has a USB cable (older models), you will need to plug it in.

  • 7
    If it doesn't work, try plugging in the display's USB cable. Apr 28, 2016 at 23:36
  • as of 2019 and macOS Mojave, neither of these answers work. I also tried plugging an external USB keyboard (Apple's) directly into the CinemaDisplay, and no luck controlling the brightness. Also ran my MacBookPro in clamshell mode and nothing happened then either.
    – esaruoho
    Feb 13, 2019 at 12:02
  • Works as of today on OSX Catalina usb plugged in a reboot required.
    – David
    Dec 4, 2019 at 15:23

I search and search, finally find this article https://discussions.apple.com/thread/2649213?start=0&tstart=0 .

Gilletty said that:

I was having the same issue on my MacBook Pro. Here is what I did to resolve it:

  1. Ensure lid of laptop is open
  2. Plug in power, mini-display, AND USB from the Cinema Display into MBP
  3. Restart computer (*this was the key step for me)
  4. When computer comes back up, launch System Preferences > Displays and you should now see the brightness option that was once hidden!

So I plug cinema display usb to iMac27, and reopen display setting, now cinema display has it own brightness controller.

lik this: enter image description here

  • 6
    The USB cable made all the difference. No reboot required these days.
    – motto
    Jul 17, 2014 at 15:37
  • Had to do the USB cable and Reboot on High Sierra, so seems to at least be required on my machine.
    – Will
    Jun 19, 2018 at 18:53
  • Gilletty thanks so much!! Just plugged my 23" Cinema Display to the new MacBook Pro and sadly, the brightness was low and no way to adjust it. Came across your great post and it worked! This is super. Fortunately there are users out there willing to share and help out, contrary to Apple whose solution is for us to buy a newer screen. Cheers
    – Joolz
    Oct 2, 2018 at 5:28
  • Wow, not sure how you figured this out, but thanks!
    – Snekse
    Nov 26, 2018 at 15:59
  • 1
    unfortunately i was unable to get this going with macOS Mojave :(
    – esaruoho
    Feb 13, 2019 at 12:08

None of the approaches work for my Cinema LED Display 24 inch. Later I found the acdcontrol software from Github. It could only be installed in the Linux machine. You may encounter a situation that the Product ID (PID) of your monitor is not listed as in the file acdcontrol.cpp. (There are more than one version of a specific monitor model.) You have to modify the Product ID in the acdcontro.cpp to your monitors' which you can find by using "acdcontrol /dev/usb/* --detect", according to the manual. And then, compile the program with "make". Good luck.


It now works when I:

  1. Plug in the USB (if yours still has one)
  2. Use DisplayBuddy to control the brightness (use the Apple Display Control in DisplayBuddy)

I use Shades. This will solve your problem. I just hope it runs on Lion too.

  • I already try it, but seems it can turn cinema display as bright as my iMac27.
    – Tinyfool
    Dec 10, 2011 at 9:25

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