Just like when you make a sound, your ears hear it, when your camera makes a sound, its built-in mic records it. While some lenses make little but audible mechanical noises when they focus, STM lenses focus in near silence, allowing you to record what you see and what you hear—without any distractions.

Racking focus is a simple technique you’ve probably seen on TV or in the movies. It simply means changing focus during a shot—for example, shifting focus from a person close to the camera, to someone further from the camera. This is a great way to get more creative with your videos, and with an STM lens, you can do it seamlessly.