What I need is to extend the delay before the display dims. I will often read a page full of text and the screen will dim, and I have to touch the trackpad. It gets annoying when trying to take notes or do homework.

This is for a 13" 2008 MacBook Aluminum.

I am aware of the pmset halfdim switch. That switch corresponds to the automatically reduce the brightness of the display before sleep in the Energy Saver preferences pane. But it's not what I need. I do like the feature, but I'd just like to extend it 15-20 seconds.


2 Answers 2


I'm not aware of a way to set the dimming time directly. You could always just increase the Display Sleep time in the Energy Saver preferences and then manually put the display to sleep when you're walking away from the machine. That's done with the combination ctrl - shift - eject

  • I've been continually searching on this for the past few days and I have found nothing to indicate it can be done. So, I'm gonna accept this as the best way to do it. Thanks
    – KyleWpppd
    Nov 12, 2010 at 17:17
  • Incidentally, if there was a way (through a hidden configuration setting) it would most likely be present in /Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist; but there are no keys in there for setting the screen dimming delay, so I'm inclined to say it's not possible, too.
    – mipadi
    Nov 12, 2010 at 20:55

The best 3rd-party based solution for you is to use Caffeine.

About Caffeine: A tiny program that puts an icon in the right side of your menu bar. Click it to prevent your Mac from automatically going to sleep, dimming the screen or starting screen savers. Click it again to go back. Hold down the Command key while clicking to show the menu.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .