Nikon N70 AF Instruction Manual page 32

A F-S Single Servo
AF
You lightly press shutter release button, the lens starts
adjusting for focus. Because the priority is on correct focus, the
shutter locks until the stationary subject is in focus (with . ) or
until the moving subjects expected to be in focus (with . . ).
After focus is achieved with a stationary subject, the focus
remains locked for as long as shutter release button is lightly
pressed. This feature is useful, especially when recomposing
the picture with the mains subject off center. However, if the
camera-to-subject distance changes, you have to refocus.
32
Stationary subject is in
focus
With a stationary subject: Lightly press shutter release button.
When the subject is in focus, the lens stops moving, the in-
focus indication . appears in the viewfinder, and focus is
locked. If the subject moves, remove your finger from shutter
release button, then lightly press it again to restart autofocus.
If. stays in the viewfinder
Subject is located closer than the closest focusing distance
of the lens. Move away from subject and refocus.