Canon POWERSHOT A480 User Manual page 72

While you press and hold the shutter button halfway, the focus and exposure
are fixed. You can now recompose and shoot. This is called Focus Lock.
Focus.
Center the subject you want in focus, and
press the shutter button halfway.
Confirm that the AF Frame on the subject
is green.
..... R ecompose.
Hold the shutter button pressed halfway
and recompose the scene.
: shoot.
Press the shutter button fully.
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