Canon EOS REBEL T2I Instruction Manual page 22

-)$ AE Lock*
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.
2
Focus the subject.
_ Press the shutter button halfway.
_y,, T he exposure setting will be
displayed.
Press the <-)6> button. (G4)
_y,, T he <%> 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 auto exposure
setting.
Recompose and take the picture.
_ If you want to maintain the AE lock
while taking more shots, hold down
the <-_ > button and press the shutter
button to take another shot.
AE Lock Effects
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AE lock is applied at the AF AE lock is applied at the
C:_3" point that achieved focus, selected AF poinL
[:oJ[[_ C:] AE lock is applied at the center AF poinL
Whenthetens'focusmode switchis setto<MF>, AElockis applied at thecenter AF point.
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