Canon 510 HS - Manual (Page 118)

Shooting Range and Focusing
118
As long as you keep the shutter button pressed halfway, the focus and
exposure are locked. You can recompose shots as needed before shooting.
This feature is called Focus Lock.
Focus.
z Aim the camera so that the subject is
centered, and then press the shutter button
halfway.
z Confirm that the AF frame displayed around
the subject is green.
Recompose the shot.
z Keeping the shutter button pressed halfway,
move the camera to recompose the shot.
Shoot.
z Press the shutter button all the way down.
This mode helps avoid missing shots of subjects in motion, because the
camera continues to focus on the subject and adjust the exposure as long as
you press the shutter button halfway.
Configure the setting.
z Touch H, touch n, choose [Servo
AF] on the 4 tab, and then choose [On]
(p. 50).
Focus.
z The focus and exposure are maintained
where the blue AF frame is displayed while
you are pressing the shutter button halfway.
Recomposing Shots While the Focus is Locked
Still Images
Shooting with Servo AF
Still Images