Ai Servo Af For Moving Subjects - Canon EOS Rebel T5i 18-55mm IS STM Kit Instruction Manual

f: Changing the Autofocus OperationN
One-Shot AF for Still Subjects
Suited for still subjects. When you press the shutter button
halfway, the camera will focus only once.
When focus is achieved, the dot inside the AF point achieving focus
lights up briefly in red, and the focus confirmation light <o> in the
viewfinder will also light up.
With evaluative metering (p.117), the exposure setting will be set at
the same time focus is achieved.
While you hold down the shutter button halfway, the focus will be
locked. You can then recompose the shot if desired.
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 picture and try to
focus again. Or see "Subjects Difficult to Focus" (p.103).
If [z1: Beep] is set to [Disable], the beeper will not sound when focus
is achieved.

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.100) 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.
98