About Color Temperature Information Transmission; About The Af-Assist Beam - Canon SPEEDLITE 580EXII Mode D'emploi

About Color Temperature Information Transmission

When the flash fires, the color temperature information is transmitted to
the EOS DIGITAL camera. This feature optimizes the flash picture's
white balance. When the camera's white balance is set to <A> or
<Q>, it will work automatically.
To see if this feature works with your camera, see "White Balance"
under "Specifications" in your camera's instruction manual.

About the AF-Assist Beam

Under low-light or low-contrast conditions, the built-in AF-assist beam
will be emitted automatically to make it easier to autofocus. The AF-
assist beam works with all EOS cameras. The AF-assist beam is
compatible with 28mm and longer lenses. The effective range is shown
below.
Periphery
Position
Center 0.6 - 10 m / 2.0 - 32.8 ft.
0.6 - 5 m / 2.0 - 16.4 ft.
Effective Range
49