How can I adjust additional cinema display screen's brightness?

Question

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.

Answer 1

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:

Answer 2

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