Advanced Techniques

AE-lock and AF-lock

Written by Gail Bjork

Some digital cameras have a powerful feature that lets you lock focus and exposure independently at the click of a lever.

Focus and exposure confirmation windowDigital cameras are set by default to lock focus and exposure together when the shutter release button is pressed halfway. Some digital cameras have a very useful feature to lock focus and exposure independently.

Besides Auto Focus Lock and Auto Exposure Lock, a camera may also have Flash Exposure Lock.

AF-Lock: controlling focus independently

Gain control over where the camera focuses when you depress the shutter button half-way. Say you want to focus on the subject that is off to one side in a scene. Move your digital camera so the focus area indicator is on the subject. Then press the shutter button down half way to lock focus. While holding the button in this position, recompose and then fully depress the button to take your shot.

This helps ensure that the main subject is in sharp focus rather than a random object in the scene selected by the camera.

AE-Lock: controlling exposure independently

Obtaining better exposed photos in difficult lighting situations involves moving the camera to the main area you want properly exposed. It should of equal distance as the subject since the shutter button controls focus too.

For example, if you want to capture detail in an area that would otherwise come out dark, lock exposure on the area, recompose and press the shutter-release button all the way down.

FE-Lock: controlling flash exposure

Flash Exposure-Lock locks exposure when taking photos with the flash. FE Lock can be very useful, as the following example illustrates.

If taking a photo of a person inside the house with a window behind them, turn on the flash and use FE-Lock to lock flash exposure on the face. The camera adjusts the flash output accordingly and the flash exposure will not be effected by the backlighting from the window.

Check your camera manual to see if your camera has these features. And, like all camera techniques, learn them by taking plenty of practice shots.

About the author

Gail Bjork

Gail Bjork, who is passionate about digital photography, is the owner and editor of Digicamhelp.Gail is the author of three illustrated ebooks about digital photography. A number of her photos and digital photography related articles appear at other websites.In 2006, a series of her photos, People in the Louvre, were exhibited at the Underground Photo Gallery
in Iisalmi Finland. Eight of her photos taken in the Florida scrub are on permanent exhibition at Parrish Medical Center in Titusville, Florida.Gail served twelve years as an elected member of The School Board of Palm Beach County, Florida, one of the largest school districts in the U.S. She has also been the editor of a small town newspaper and a free-lance writer. Gail and her husband owned and ran several small businesses.

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