Step by step Activate the autofocus
There are a number of ways to start the autofocus ball rolling on a digital camera
The default way to trigger the autofocus is by a half-press of the shutter release button. If the autofocus mode is set to One Shot or Single Shot AF, the focus will stay locked in as long as you keep the shutter pressed halfway down.
One or more buttons on the rear of an SLR can be configured to activate or deactivate autofocus. Being able to start and stop it independently of firing the shutter allows you to effectively switch between continuous focus and single shot autofocus.
Some cameras have a touchsensitive display, allowing you to tap on the area of the picture of you want to focus on. This is just as effective for shooting movies as well as stills, allowing you to achieve cinematic ‘focus pulls’ by tapping on different objects.
Using a wired or wireless release allows you to trigger the autofocus without touching the camera. If your camera is Wi-Fi enabled, then you can also operate it using the manufacturer’s app on a mobile iOS or Android device.