Talk:Controls/@comment-74.105.213.230-20140426055037/@comment-67.237.191.203-20140507044427

You have two options. The first is to press the "fn" key, and then press F1 while holding it. The second option is to open System Preferences > Keyboard > Check the box marked "Use all F1, F2, etc. keys as standard function keys."

From there, if you want to decrease brightness with F1, you would press "fn" and F1 just like the first option.