I just bought XPS one 2720. Monitor was too bright and I tried to dim it. Manual control on the front panel does not dim down at a certain level. I tapped the setting charm and found brightness icon. But the brightness icon has a mark "unavailable".
How to make this brightness icon to work?
Since the XPS 2720 is an all-in-one desktop computer, the brightness option in the charms bar will be disabled. The reason is, Windows 8 is designed in such a way that when it gets to know that it is being installed on the desktop, certain features are disabled by default. Like the brightness for itself. And on the other hand, if this was in case of a laptop, then the brightness feature would have been enabled. Hence comes in use the OSD (On Screen Display) buttons on the all-in-one itself. But they can only dim the brightness upto a certain level and not below that, as you have mentioned in the post.
Now the answer to your question "How to make this brightness icon to work?" is that we cannot make it to work. But, there is another way to decrease the brightness. Here is how:
Your XPS 2720 comes with Intel Graphics as well as Nvidia Graphics. So right-click on the empty space on the desktop and select Graphic Properties. A window should open up for Intel HD Graphics Control Panel like in the picture below:
Now, go to Display ---> Color ----> and try adjusting the Hue / Saturation / Brightness and see if the display brightness meets your needs.
Hope this helps.
That's not a sufficient solution, especially as the previous model XPS One 2710 actually DOES feature the brightness-setting via the Charms bar. And it's really handy, I might add. So there's no reason to not support this feature in the newer XPS 2720. What can be done about this?
I never had a problem with glare from a monitor in over 20 years of daily use until I bought the XPS 2720. The screen is far too bright even at its lowest setting particularly when working at night with applications where the background is white. This problem is making an otherwise excellent computer unusable.
Changing the brightness in the Graphics Properties is not the same as changing the overall brightness with the Display Settings Control on the front panel. The control needs to be changed to cover a much lower range either by a firmware update or by enabling the windows brightness control. Does Dell have any intention of fixing this?