Canon A2100 IS - Manual (Page 19)

19
The shutter button has two stops. To take images that are in focus, be sure
to first press the shutter button lightly (halfway) to focus, then take the shot.
Press halfway (lightly to the first
stop).
X The camera automatically makes the
necessary settings for shooting, such as
focusing and setting the brightness.
X When the camera focuses, it will beep
twice and the indicator will light green.
Press fully (to the second stop).
X The camera plays the shutter sound and
takes the shot.
Pressing the Shutter Button
If you just press the shutter button fully without pausing halfway, the
image may not be in focus.