Canon AF 35 ML - Manual (Page 30)

Prefocusing
O
When you wish to compose the picture so
that your subject is not in the center of the
viewfinder and the autofocus frame is,
therefore, not covering the subject, follow
these steps;
Look into the viewfinder and compose the
picture so that the autofocus frame covers
your subject. Gently press the shutter button
HALFWAY and make sure one of the zone-
focus symbols lights up. This allows the
camera to "memorize" the subject distance.
2 Keeping the shutter button pressed half­
way, recompose the picture as you like, but
do not change the shooting distance.
3
Press the shutter button all the way down
to take the picture