Minolta Dynax 7xi Instruction Manual page 60

AE LOCK
To lock the exposure system independently of the autofocus system,
position your subject in the viewfinder and press the AE lock button; AEL
will appear in the viewfinder data panel. Hold the button in as you
recompose and take the picture.
• If you release the AE lock button before you take the picture, the
exposure system will re-evaluate the scene and continue functioning as
normal.
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