Autofocus (AF) is an optical system that uses a sensor, a control system and a motor to focus on an automatically or manually selected point or area. The process of autofocusing generally works as follows:
- An autofocus processor (AFP) makes a small change in the focusing distance.
- AFP reads the AF sensor to assess whether and by how much focus has improved.
- Using the information from (2), the AFP sets the lens to a new focusing distance.
Autofocus systems can be found on film and digital cameras.
