Olympus iS-3 DLX Instructions Manual page 20

Depress the shutter
release button halfway.
Make sure
The autofocus beep is heard and the
autofocus indicator lights when the subject is in focus.
It will blink if the subject is difficult for the autofocus to
lock on, and when the subject is too close.
Note: When the autofocus indicator blinks, the shutter
won't release. (See p. 70.)
20
Depress the shutter release
button fully to take the picture.
The shutter releases and the film
automatically advances to the next
frame.