Ai Servo Af For Moving Subjects - Canon EOS 6D Instruction Manual

If focus cannot be achieved, the focus confirmation light <o> in the
viewfinder will blink. If this occurs, the picture cannot be taken even if the
shutter button is pressed completely. Recompose the shot and try to
focus again, or see "When Autofocus Fails" (p.96).
If [z1: Beep] is set to [Disable], the beeper will not sound when focus
is achieved.
After achieving focus with One-Shot AF, you can lock the focus on a subject
and recompose the shot. This is called "focus lock". This is convenient when
you want to focus a peripheral subject not covered by the AF points.

AI Servo AF for Moving Subjects

This AF operation is suited for moving subjects when the focusing
distance keeps changing. While you hold down the shutter button
halfway, the subject will be focused continuously.
The exposure is set at the moment the picture is taken.
When the AF point selection (p.94) is automatic, the camera first
uses the center AF point to focus. During autofocusing, if the subject
moves away from the center AF point, focus tracking continues as
long as the subject is covered by another AF point.
With AI Servo AF, the beeper will not sound even when focus is achieved.
Also, the focus confirmation light <o> in the viewfinder will not light up.
AI Focus AF for Switching the AF Operation Automatically
AI Focus AF switches the AF operation from One-Shot AF to AI
Servo AF automatically if a still subject starts moving.
After the subject is focused in One-Shot AF, if the subject starts moving,
the camera will detect the movement, change the AF operation
automatically to AI Servo AF, and keep tracking the moving subject.
When focus is achieved with AI Focus AF with the Servo operation active,
the beeper will continue beeping softly. However, the focus confirmation
light <o> in the viewfinder will not light up. Note that focus will not be
locked in this case.
f: Selecting the AF OperationN
93