70
AF Point Activation Area
C.Fn-17
C.Fn-17 can be set to expand the AF point’s activation area to include more than one active
AF point. (→p.137) See “Setting a Custom Function” on page 132.
•
C.Fn-17-1 Expanding the activation area to 7 points
(→p.137)
This larger activation area makes it easier to focus subjects moving irregularly.
•
The expanded AF point activation area is not
displayed in the viewfinder.
•
When focus is achieved in the One-Shot AF mode,
the selected AF point and the AF point(s) achieving
focus will light.
C.Fn-17-1
: Selected AF point.
: AF points in expanded
activation area.
•
C.Fn-17-2 Expanding the activation area to 7 or 13 points automatically
(→p.137)
As shown below, the AF point activation area expands automatically to 7 or 13 points depend-
ing on the lens focal length, AF mode, and the subject’s speed in the AI Servo AF mode. This
is effective when the subject’s movement is unpredictable.
C.Fn-17-2
AF Mode
Lens Focal Length
Shorter than 300mm 300mm or Longer
One-Shot AF
AI Servo AF
The activation area does not expand
automatically.
The activation area expands by one point.
For a slow-moving
subject
For a fast-moving
subject
For a slow-moving
subject
For a fast-moving
subject
aa
∗ To set the Custom Function, see “Setting a Custom Function” on page 132.
