3Custom Function SettingsN
C.Fn III: Autofocus/Drive
C.Fn-7 AF-assist beam firing
Enables or disables the AF-assist beam of the built-in flash or the EOS-dedicated external Speedlites.
0:Enable
The AF-assist beam will be emitted when necessary.
1:Disable
The AF-assist beam is not emitted. This prevents the AF-assist beam from disturbing others.
2:Enable external flash only
If an external Speedlite is attached, it will emit the AF-assist beam when necessary. The camera’s built-in flash will not fire the AF- assist beam.
3:IR AF assist beam only
When an external Speedlite is attached, only an infrared AF-assist beam will be emitted. This prevents any Speedlite which uses a series of intermittent flashes (like the built-in flash) from firing the AF-assist beam.
With an EX-series Speedlite equipped with an LED light, the LED light will not automatically turn on for AF-assist.
If an external Speedlite’s [AF-assist beam firing] Custom Function is set to [Disabled], the Speedlite will not emit the AF-assist beam even if the camera’s C.Fn-7 is set to 0, 2, or 3.