Canon EOS-1D C EOS 1D X Instruction Manual - Page 95

3 Customizing AF Functions AF-assist beam firing Enables or disables the EOS-dedicated Speedlite's AF-assist beam. ON: Enable The external Speedlite emits the AFassist beam when necessary. OFF: Disable The external Speedlite will not emit the AF-assist beam. This prevents the AFassist beam from disturbing others. IR: IR AF assist beam only Only external Speedlite models that have an infrared AF-assist beam will emit the AF-assist beam. Set this if you do not want the AF assist using small flashes to be emitted. If the external Speedlite's Custom Function [AF-assist beam firing] is set to [Disable], the AF-assist beam will not be emitted, regardless of this function's setting. One-Shot AF release priority You can set the AF operation characteristics and shutter-release timing for One-Shot AF. : Focus priority The picture is not taken until focus is achieved. Effective when you want to achieve focus before capturing the shot. : Release priority Priority is given to taking the picture instead of achieving focus. This gives priority to getting the shot. Note that the picture will be taken even if focus has not been achieved. 95