A portrait can change brightness when the camera moves slightly. Include more bright sky and the face may darken; exclude the sky and the camera may choose a different exposure. The light on the subject has not necessarily changed, but the metered scene has.
Auto Exposure Lock, often labeled AEL or AE Lock, helps retain a selected exposure while the composition changes. It is useful when the current exposure is appropriate and you want to preserve it deliberately.
Meter the part of the scene that matters
Sony describes AE Lock as a function for reframing while keeping the current exposure from changing. It can also help maintain consistent exposure between shots.
Begin by deciding what needs to be exposed appropriately. In a portrait, that may be the face. In a product image, it may be the surface whose detail must remain visible.
Position the camera and choose the exposure you intend to retain, then activate the lock according to the camera’s controls.
The lock preserves a decision; it does not establish that the decision is correct. Review the result before building an entire series around it.
Recompose and check focus separately
Once exposure is locked, adjust the framing and make sure the intended subject remains in focus.
Sony’s documented AE-lock procedure includes locking exposure, focusing on the subject again, and taking the photograph. This illustrates why exposure and focus should be treated as separate concerns.
For example, a subject may be placed near the center while establishing exposure and then moved toward one side of the composition. The final focus still needs to correspond to the subject’s position and distance.
Watch for accidental assumptions about the shutter button. Camera settings can change whether a half-press affects exposure, focus, or both.
Learn hold and toggle behavior
Some camera configurations keep exposure locked only while the assigned button is held. Others provide a toggle that remains active until released by another action.
Sony’s help guide documents both hold-style use and an AEL toggle option on the referenced model. The exact availability and controls depend on the camera.
Practice the behavior before a time-sensitive shoot. Activate the lock, reframe, release the button, and observe the indicator. Repeat until you can tell when the camera is still using the locked exposure.
A forgotten toggle can make the next scene look unexpectedly bright or dark. Checking the lock indicator is therefore part of moving between compositions.
Use a controlled comparison
Try a scene with a stable subject and a noticeably brighter background. Take one photograph after reframing with exposure free to change, then another using AE Lock.
Compare the subject rather than judging only the average brightness of the entire image. The test should show whether the lock preserved the exposure you intended.
Next, change the actual lighting on the subject. The previously locked setting may no longer be appropriate. This demonstrates the limit of the technique: it prevents automatic changes, including changes that might now be helpful.
AE Lock works best as a short, deliberate step in a shooting sequence. Establish the exposure, lock it, recompose, confirm focus, make the image, and reassess when the light or subject changes.