just sharing another 'puzzling thing' with sgs2...
well, for me anyway...
the brightness settings can be confusing. just like the volume. it can affect others apps in a weird way.
i normally set screen brightness to the lowest since its more than bright enough. however, when set to lowest, it will affect the stock camera apps. i totally can't see the camera apps screen under broad daylight.
if i set to auto, normal phone operations is still fine. but i believe the ambience sensor dun work during camera apps... i need to set the display brightness to max.
then there's the time when i use my stock browser. in the browser, there's the brightness settings as well... you set it to auto, you also change the settings on your display brightness back to auto... and then... it affects the rest...
*sigh*
so end up... before using camera under sun, i try to remember to set brightness to max. when at other times, i set to auto but it does make browsing unformfortable -- so sometimes have to set to manual brightness (say 40%)... at night, i try to remember to change brightness to lowest else when i browse, get blinded by the 40% brightness in a dark room...