I've been tweaking around with the automatic brightness settings, and here's some interesting information I've found so far: 1). Ambient light sensor minimum value is 10, so don't bother setting a level of 0-9, it'll never get activated. I made my first level 0-10 to catch the lowest light values. 2). Keyboard and button backlighting is either on or off - a value of 0 is off, and anything else is on. 3). Button lighting is WAY brighter than the low screen backlight levels. 4). Screen backlight levels 5 and below are actually screen off. 6 is the first one that you can see at all (and you can't really see it if there is much of any light around - it's only good in the complete darkness). 5). The "Screen dim level" setting selects the minimum brightness level you can use for the automatic brightness configurations AND sets the dim level it will use when dimming the screen. And it will use it when dimming *regardless of the ambient light level*. If you pick a value lower than 10 so and use your phone in normal light conditions, the screen will appear to be off when it is actually just dimmed. You'll notice it because you'll have to hit the power button twice to turn it on (the first press is actually turning it off). EDIT: Just found a workaround! Set your "Screen dim level" to the lowest value you want (6 or 8 or whatever) and reboot. When the phone is back up, set up your automatic brightness levels to be what you want. Then set "Screen dim level" back to 20 and reboot again. Your level settings below 20 will remain, but your dim will still be set at 20. The bizarre result is that if you are using the phone in the dark, it will actually get BRIGHTER when it tries to dim.