If you've ever taken a blurry photo – and let’s face it, who hasn’t – or had to wait for your camera to focus and lost your chance to capture that one, perfect image, the Focus Lock feature is for you.
Pre-focus your image to reduce blur.
The easiest and most common fix for blurry images is to depress the shutter button halfway, this lets the camera focus before you actually take the shot. Simply press the shutter button until a green dot appears on the LCD, or until a beep sounds. Once you see the green dot, or hear the beep, your camera is focused and you have a much greater chance of taking an in-focus shot.
Prevent shutter lag.
When used properly, auto focus is a great feature that can help you capture clear images in a variety of shooting situations with a minimum of fuss. However, it increases shutter lag because the focus is only sought and obtained after the shutter button is pressed. To use Focus Lock, simply press the shutter button halfway down once you have composed a shot. The lens will move into position, and the camera will focus. When you press the shutter button completely down to take the shot, the camera will not have to focus, resulting in an appreciable decrease in shutter lag for that shot.
Most people center their subject in the frame when shooting. However, from time to time you will want to take more creative or artistic shots by moving the subject off center. This is possible with the Focus Lock feature.
AF Target Mark:
Located in the middle of your viewfinder is the Auto Focus (AF) Target Mark. When you press the shutter button down halfway the camera will focus on anything located behind that mark. In the example below our subject is off center and thus out-of-focus:
Since the camera locks focus at the halfway pressing of the shutter button this gives you the opportunity to recompose your shot before fully pressing the button to take the shot.
Follow these steps to lock focus:
Position the AF mark on your subject and press the shutter button halfway. When the green lamp blinks (on the LCD) focus and exposure are not locked. When the green light is steady, both focus and exposure are locked.
Keeping the shutter button pressed halfway, recompose the shot and press the shutter button completely.