User Manual Page 70 - Av:
Using the Built-in Flash
The flash exposure will be set automatically to match the aperture that was set. The shutter speed will set automatically between 30 sec. -1/200 sec.to suit the scene's brightness.
In low light,the main subject is exposed with the automatic flash,and the background with a slow shutter speed set automatically.
Both the subject and background look properly exposed (automatic slow-speed fash sync). .........