Autofocus Cameras

Autofocus cameras typically use a computer to run a miniature motor that focuses the lens for you. There are two types of autofocus systems, active and passive. Single-lens reflex cameras with interchangeable lenses typically use the passive autofocus system. Cameras without interchangeable lenses usually use active infrared sensors.

Researched by NONA YATES / Los Angeles Times

Source: https://www.howstuffworks.com

How Stuff Works: https://www.howstuffworks.com