V1.02
Thom Hogan’s Complete Guide to the Nikon D300
Page 388
Dynamic Area AF
—the camera starts by focusing on
the subject under the currently selected autofocus sensor,
but
if Continuous Servo AF is set
, may use another sensor
if it detects that the subject is moving. You control which
sensor the system
starts
focusing with by pressing the keys
of the Direction pad on the back of the camera (when the
meter is active). You also control how far from the
selected autofocus sensor the camera will follow a moving
subject (9, 21, 51, or 51 3D, set via Custom Setting #A3).
Auto Area AF—
the camera
always
determines focus
by itself, based upon a number of factors, including a
crude face recognition scheme if you’re using G-type or
D-type lenses (which supply distance info to the camera);
you get no choice in which autofocus sensor will be used
for focusing; the camera evaluates all fifty-one sensors.
õ
The autofocus area that is used as the initial focus point (or
the points that form the “group”) is set by:
1.
Moving the Focus Area Selector Lock lever to the
unlocked position (lever down to the dot position).
2.
Making sure the camera is active (press the shutter
release partway and release it if the camera isn’t
active).
3.
Pressing the keys on the Autofocus Direction pad to
change sensors (by default, the directions don’t wrap
around, so pressing left continuously just takes you to
the left sensor and stops [see “Focus Area Selection
Wrap” on page <532>]). If the Autofocus Area mode
is set to Auto Area, you don’t get to pick an initial
sensor. The viewfinder shows you which sensor(s)
you’ve picked by highlighting it (at the camera
defaults, with a brief flash of red or bold black
markings for the current autofocus sensor).
This is a good time to take a breather and suggest an
approach to mastering this new autofocus system. It should be
clear that Single Servo, Single Point is straightforward: the
camera only focuses on the spot you pick, and the camera
