[Tuning] Unable to change brightness

[Link_wf]

I can change the brightness value but it only affect the hud and menus, not the scene itself.

Here is some screenshots :
min :


medium :


max :


Also, the menu become unusable when set at extreme values :

min :


max :


My system :
Win 7 64
AMD phenom 2 x4 965
AMD radeon 6950 (catalyst 11.8)

Can anyone confirm this problem ?
Is there workaround ?

 

[Link_wf]

After reading this thread, I re-enabled dof and it is now possible to adjust brightness.

So, is there a way to disable dof and adjust brightness at the same time?

Playing with dof is not a solution, it's ugly, annoying and it reduce a lot the frame rate.