Nikon D100 Manual page 81

Camera focuses on subject in selected focus area. Focus
will remain locked while shutter-release button is pressed
halfway.
Camera focuses on subject in selected focus area. If subject
moves before camera has focused, camera will focus based
on information from other focus areas. Focus will remain
locked while shutter-release button is pressed halfway.
As above, except that camera focuses on subject in focus
area containing subject closest to camera.
Camera continues to focus on subject in selected focus
area while shutter-release button is pressed halfway.
Camera focuses on subject in selected focus area. While
shutter-release button is pressed halfway, camera tracks
subject as it moves from one focus area to the next.
As above, except that camera focuses on subject in focus
area containing subject closest to camera.
How it works
Controlling How the Camera Focuses
When to use it
Use with static subjects
when time is available to
compose photo.
Use with static subjects
when time is available to
compose photo.
Use when you know your
subject will be closest ob-
ject to camera but you are
unsure where it will ap-
pear in final composition.
Use with subjects that are
moving towards or away
from you.
Use with subjects that are
moving unpredictably.
Use with erratically mov-
ing subjects when you
know your subject will be
closest object to camera.
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