Sony SLT-A58 - Manual (Page 42)

Using the flash
GB 42
(Flash Off) Does not fire even if the flash is raised.
• You cannot select this item when the mode dial is set to P,
A, S, or M. If you do not want to use the flash in these
modes, push the flash down.
(Autoflash) Fires in dark environments or when shooting towards bright
light.
(Fill-flash) Fires every time you trigger the shutter.
(Slow Sync.) Fires every time you trigger the shutter. Slow sync shooting
allows you to shoot a clear image of both the subject and the
background by slowing the shutter speed.
(Rear Sync.) Fires right before the exposure is completed every time you
trigger the shutter.
(Wireless) Fires an external flash (sold separately) that is off the camera
and away from it (wireless flash shooting).