Back-button focusing
Speed up your work by reassigning AF tasks
The method of activating autofocus by half-pressing the shutter release is the default setup in many cameras. But although it may be familiar, it isn’t necessarily the most effective way of working with AF. Many pro sports and wildlife photographers reassign AF activation to the AF-ON button, located on the back of EOS cameras. This button is designed to be accessible to your thumb and by turning on back-button focusing, you can activate autofocus without using the shutter release button.