Tell me more ×
Ask Different is a question and answer site for power users of Apple hardware and software. It's 100% free, no registration required.
up vote 1 down vote favorite

I have periodically noticed that my display has been a bit dim, and have brought it up to maximum brightness... only later to find that my display was about halfway on brightness. I can't rule out a stray keystroke, but it seems to be several notches down a lot more often than I would accidentally hit F1. As far as I can tell this happens when the computer remains on and I remain logged on.

Especially when operating on battery power, does Mountain Lion dim the display automatically? Is there a way to turn off or circumvent this?

share|improve this question
I actually find the opposite frustrating: I typically use my computers at near-minimum brightness and it's very annoying when I reconnect to power or go into a bright room and the display is suddenly blaring with light. – CajunLuke Sep 19 '12 at 21:14

1 Answer

up vote 1 down vote

When you go from mains power to battery, OS X decreases display brightness. (It should go back to normal brightness when you reconnect to mains power.)

To turn this off, go to System Preferences > Energy Saver, choose the Battery tab, and un-check "Slightly dim the display when using this power source".

The display can also change brightness because it senses a change in ambient brightness. To turn this off, go to System Preferences > Displays, find the window on the display you want to change this setting on, go to the Displays tab, and un-check "Automatically adjust brightness".

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.