Canon MARK III EOS-1 DS Instruction Manual page 172

3 Custom Function Settings
C.Fn III -13
0: Normal
1: Brighter
C.Fn III -14
Enables or disables the EOS-dedicated Speedlite's AF-assist beam.
0: Enable
The external Speedlite will emit the AF-assist beam when necessary.
1: Disable
The external Speedlite's Custom Function [AF-assist beam firing] set to
[Disable] will override this Custom Function's 0 setting.
C.Fn III -15
See page 104 for the mirror lockup procedure.
0: Disable
1: Enable
2: Enable: Down with SET (button)
With setting 1 and 2, the <2> icon will appear on the top LCD panel.
C.Fn III -16
Disable: Continuous shooting will be enabled: <o>: Approx. 5 fps,
<p>: Approx. 3 fps
Enable: The continuous shooting speed set with [Register] will be enabled.
Register: <o> can be set within 2 fps to 5 fps, and <p> can be set
within 1 fps to 4 fps. After entering the settings, select [Apply].
C.Fn III -17
Disable: No limit is set on the continuous shot count. (Continuous
shooting will be possible up to the maximum burst indicated.)
Enable: The continuous shooting will be limited to the number set with
[Register] after which the shooting will stop automatically.
Register: The continuous shot count can be limited to 2 to 99. After
entering the settings, select [Apply].
172
AF point brightness
AF-assist beam firing
Mirror lockup
Continuous shooting speed
Limit continuous shot count