Sony mvc-cd250 Operating Instructions Manual page 74

Once you press AE LOCK, the exposure,
now captured, is fixed. For insfance, this
function is convenient in the following use:
Measure the exposure of the desired portion
of the image using the spot metering
function and fix the exposure value by
pressing AE LOCK. Then, recompose tbe
picrure.
Fix
the exposure.
Shoot the subject
The exposure is fixed and the AE-L
indicator appears.
The focus is automatically adjusted.
Carry out one of the followings:
* Press AE LOCK again after step
kom the shutter
- Press down the shutter button in step