AE lock (AEL)
AE-lock (AEL) · Exposure
A button or function that locks the exposure setting so you can reframe without the exposure changing.
Meter the exposure on the right area (e.g. the face), press AEL, then reframe to the desired composition. Useful in combination with spot metering. Not to be confused with AF-lock, which locks focus.
Tools that help with this: