Canon EOS 450D - Manual (Page 88)

88
Use AE lock when the area of focus is to be different from the exposure
metering area or when you want to take multiple shots at the same exposure
setting. Press the button to lock the exposure, then recompose and
take the shot. This is called AE lock. It is effective for backlit subjects.
1
Focus, then press the <A>
button.
(0)
Press the shutter button halfway.
X The exposure setting will be
displayed.
X The icon lights in the viewfinder
to indicate that the exposure setting is
locked (AE lock).
Each time you press the button,
it locks the current exposure setting.
2
Recompose and take the picture.
* When the lens’ focus mode switch is set to <MF>, AE lock is applied at the
center AF point.
A AE LockN
AE Lock Effects
Metering Mode
(p.77)
AF Point Selection Method
Automatic Selection Manual Selection
q *
AE lock is applied at the AF
point that achieved focus. AE lock is applied at the
selected AF point.
wre
AE lock is applied at the center AF point.