Digital Camera Focus Mode: Face-Priority AF
Digital cameras come with lots of focus modes; you'll find yourself only using a few of them. One that almost every photographer, both amatuer and professional, will often use is face-priority auto focus. People are the main subjects in the majority of photos that are taken. What face priority does is it uses facial recognition technology to realize that it is taking a picture of a person. It then uses the face as the focal point of the shot.
Understanding Face-Priority AF
Cameras that have face-priority modes can identify and focus on three faces in a shot on average. The camera will stay locked on the face as long as the person remains in the frame. Most work by displaying a box around a subjects face. The box first appears as red and then turns to green. The red means that a face is recognized, but the focus is not ready. Once the box turns green, you're free to shoot away.
This is very useful for portrait photographers, as well as the amateurs shooting a Saturday night out. A user can go and shoot quick snap shots of people that will look sharp and in focus. You can now get great shots of your friends as easily as turning on your camera and hitting the button.