CHANGE MODES

High-spec digital cameras feature multiple autofocus modes, each designed to handle the specific nature of subject movement common to various shooting scenarios. While any of these modes will accurately measure subject distance, your choice of mode will determine how the camera reacts to changes in the composition. No single option is ideally suited to all shooting conditions, so it is important to understand how each type of subject movement poses a challenge to the AF system, and therefore which mode you should choose for every situation. While terminology often differs between manufacturer, the overall functionality of modes on most DSLRs and CSCs is similar, so make sure that you familiarise yourself with those featured on your camera.

1 SINGLE-SHOT AF

Often the default mode, this focuses in a single movement and locks the lens distance until the shutter button is released and halfpressed again. Useful for landscapes, portraits and other stationary subjects, it is the most reliable when you do not wish focus to shift.

2 CONTINUOUS AF

Al Servo and AF-C in Canon and Nikon terms respectively, this mode is for tracking a moving subject. Once AF is activated, focus will be continuously shifted to keep the subject sharp. Remember to tailor AF sensitivity to control how quickly the lens is focused.

3 PRIORITY AF

Al Focus mode on Canon cameras will select between single shot and servo depending on the perceived subject motion – useful when you are unsure which conditions to expect. On Nikon models AF-C priority selection allows priority for focus accuracy or burst rate.