Lenovo Y500 can't set brightness

I installed Xubuntu 12.10 on my new Lenovo Y500 and also could not adjust brightness, it was at at maximum and could not be controlled. Get installed and used graphics driver:

lshw -c video

Gave me:

configuration: drigver=nouveau latency=0

• changing the value in /sys/class/backlight/acpi_video0/brightness does not change brightness
• booting with acpi_backlight=vendor does not change brightness
• etpci -s 00:01.0 F4.B=XX (XX = 00 to ff) does not change brightness

For the moment I solved this by installing the nvidia driver:

sudo apt-get install linux-source
sudo apt-get install linux-headers-generic
sudo apt-get install nvidia-current-updates

This gives you the terminal command:

sudo nvidia-settings 

Go to: DFP-0-(LGD), Tab: Color Correction

Here you can set the brightness.