I just received my ThinkPad Twist running Windows 8 and have an issue with the screen brightness; it changes while I use the device in an unpredictable way which is just annoying me as I prefer to work with full screen brightness and hence, disabled the Energy Saving settings that would dim the screen after some minutes of inactivity.
Still the screen just dims from time to time (also while I am working) and also changes back to full brightness in a similarly unpredictable way. Those changes in brightness might take some minutes between them...
What software settings I should consider?
Also, the laptop appears to have an ambient light sensor. Could those changes in screen brightness be related to this sensor? So far the light conditions remained the same in spite of me not switching on or off the lights. Covering the position of the sensor did not induce any reaction.
The above symptoms are that of the Ambient Light Sensor feature.
To disable this or make changes to the settings, go to the Advanced Section of the Windows Power Settings >> Display >> Auto Dim.
Check control Panel > Power Options and select maximum performance
Next choose change plan settings. You can set when to dim the display when on AC or while on battery.
Here, we have selected "never" for both, and have adjusted up to full brightness - this may only make sense for test purposes, or for plugged in mode. On battery, full brightness and never dimming will reduce battery run time.
Lastly, click the blue link at the bottom to change advanced power settings...
Scroll down to the section for adaptive brightness and click the + to expand the section. Now you can select to enable or disable this on both battery and plugged in (AC) mode. If you had already made the changes in the steps above and notice the auto dimming while on battery, toggling off on battery here should keep the display at your selected brightness levels at all times (based on your power plan settings above).