Canon EOS 5D MARK II Instruction Manual page 7

Av" Aperture=Priority AE
in this mode, you set the desired aperture and the camera sets the
shutter speed automatically to obtain the correct exposure suiting the
subject brightness. This is called aperture-priority AE.
A higher f/number (smaller aperture hole) will make more of the
foreground and background fall within acceptable focus. On the other
hand, a lower f/number (larger aperture hole) will make less of the
foreground and background fall within acceptable focus.
* < Av > stands for Aperture value (aperture opening).
Sharp foreground and background
(With a small aperture opening)
Blurred background
(With a large aperture opening)
Set the Mode Dial to <Av>.
Set the desired aperture.
_ While looking at the LCD panel, turn
the <_> dial.
_,_ Focus the subject.
® Press the shutter button halfway.
_y,, T he shutter speed is set automatically.
B___llWl_:_ Check the viewfinder display and
shoot.
_ As long as the shutter speed is not
blinking, the exposure will be correct.
92