Howto Lower brightness on Apple LCD Monitor? ; jor

[giovanni_re]

I've just installed an Apple Cinema Display (LCD) monitor. This is a 5 year old monitor.
Using KUbuntu 10.4

The apple website indicates this monitor has:
User controls (hardware and software):
  	Display power, system sleep, system wake, brightness and display tilt

Brightness is what I want to turn down.

Looking in the 
KDE System Settings > General > Computer Administration > Display > Size & orientation > DVI-0

there is no adjustment for brightness.

Anyone know how to decrease brightness on this?

Thanks :)