Canon PowerShot V10 Advanced User's Manual page 261

Note
[Screen off] applies while the shooting screen is displayed. These settings do not
apply during menu display or image playback.
The camera turns off during menu display or image playback after the time set in
[Screen off] and [Auto power off] elapses.
To protect the screen, the screen turns off 30 min. after it is dimmed (although the
camera itself remains on), even if [Screen off] and [Auto power off] are set to
[Disable].
Power saving settings do not apply during shooting, or when connected via USB or
wirelessly.
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