Canon A650 IS - Manual (Page 104)

Various Shooting Methods 102
Changing the Shutter Speed and Aperture Value
Combination
The automatically selected combinations of shutter speeds and
aperture values can be freely changed without altering the exposure
to shoot images (Program Shift).
1
Aim the camera at the subject on which you
wish to lock the exposure.
2
Press the shutter button halfway and press
the button.
• The exposure setting will lock and
will display.
3
Change the shutter speed and aperture value
combination with the or buttons.
4
Recompose the image and shoot.
• The setting will cancel after the shot is taken.