Canon PowerShot SX10 IS User Manual page 66

Night Display
When shooting at dusk or during the evening when the dark
surroundings make it difficult to view the LCD monitor or the
viewfinder, the camera's "night view" option displays the subject
brightly in the LCD monitor. This will allow you to compose a shot
even in dark environments (this setting cannot be turned off).
*
Although noise may appear and the movement of the subject shown on the LCD
monitor or the viewfinder may appear somewhat jagged, there is no effect on the
recorded image. The brightness of the imqge displayed in the LCD monitor or the
viewfinder, and the brightness of the actual image recorded will be different.