100 photography tips in 100 days: Day 98
As digital cameras have evolved, so have their autofocus features. This is great news if you want to place your subject somewhere other than the center of the frame.
Most point-and-shoot cameras and some DSLRs these days have Face Detection (also known as face priority AF), which helps the user get sharp images of subjects such as two people standing next to each other.
Left of center: The off-center subject gives the image better balance and contrasts well with the blurred background. I focused on the boy's jacket, depressed the shutter halfway, then recomposed and then captured the whole scene. Photo © Andrew Darlow
Common autofocus features found on many cameras include spot, 3-point, and 9-point focusing. 9 point focusing takes into account a significant section of the viewfinder (creating a series of points where the camera looks for contrast). If 9-point (or even 3-point focusing in some cases) is used, subjects such as two people standing next to each other with space in the middle of the frame will probably be in focus.
What if your camera doesn't have face detection or multiple point autofocus? It's easy to make a mistake and focus on the background when shooting an off-center subject, but it's also easy to overcome that problem using spot focus, if your camera has that feature.
Here's how: First set your camera to spot focus mode (and single shot--not "Al Servo AF," which will track a subject and not lock focus. Al Servo is commonly used for sports or wildlife photography). Then point your spot focus target (the center of the finder) at a subject. Press the shutter release halfway and recompose, placing your subject off-center, while still holding the shutter release partway down. When you’re happy with the composition, fully depress the shutter. That’s it!