Canon EOS-1DX MARK II Settings Manual page 8

Various settings for AF-related features can
be made with AF menus [AF2] – [AF5]
The [AF2] tab includes settings related to the camera
priority concerning shutter-release timing when using AI
Servo AF. [AI Servo 1st image priority] and [AI Servo
2nd image priority] make it possible to make focusing
the priority slowing the shutter-release timing, or
prioritize faster shutter-release.
Within the [AF3] tab, the [One-Shot AF release priority]
settings sets focusing and shutter-release timing when
using One-Shot AF. The options [Lens electronic MF]
and [AF-assist beam firing] control the manual focus
operation of some lenses and the operation of AF assist
function of attached Speedlites.
AF2 AI Servo
Settings related to
shutter-release
timing when using
AI Servo AF and
continuous shooting
AF3 One-Shot AF
Settings related to
focusing and shutter
release timing etc.
when using
One-Shot AF
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