AE Lock (AEL).
Also auto-exposure lock. A common feature on many SLRs with automatic exposure which allows you to lock in the current exposure settings for a period of time, regardless of what happens to the incoming light levels in the viewfinder.
Lets say youre taking a photograph of a scene which contains one very bright light source in the corner. Normally this bright light will fool the automatic exposure system into thinking that the scene is brighter than it really is. What you really want is for the camera to meter the scene without the troublesome bright light being in there.
Now you could just turn off the light if its under your control. But that wont help you if the bright light originates from the sun or from other source you cant switch on or off at will.
So another way to do this is to move the camera slightly so that the bright light no longer appears in the viewfinder. When this happens well assume that the scene now contains the light levels you really want to meter for. You can then press the AEL button (often marked with the * symbol on Canon cameras, for example) to lock in whatever the cameras light meter believes are the correct settings.
Now when you move the camera back so that the bright light is visible once again the correct exposure settings are retained and you can take your photograph. This is a typical use for AEL.
cf. automatic exposure (AE), flash exposure lock (FEL).
Entry last updated 2002-04-03. Term 87 of 1487.
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