What does camera autofocus mean?

Auto-focusing refers to the way that the reflected light is received by the sensor CCD on the camera and focused by the computer by using the principle of object light reflection. It can be divided into two categories: one is active and the other is passive.

Has the following three characteristics.

1, which automatically judges the subject photographed by the photographer in some way;

2. Measure the distance between the object and the photosensitive element of the camera in some way;

3. Drive the motor to push the focusing device of the lens to the corresponding distance scale.

Extended data:

How the camera works:

Convert optical image signals into electrical signals for storage or transmission. When we shoot an object, the light reflected by the object is collected by the camera lens and focused on the light receiving surface of the camera device (such as the target surface of the camera tube), and then the light is converted into electric energy by the camera device, and a "video signal" is obtained.

The photoelectric signal is very weak, so it needs to be amplified by pre-amplifier circuit and then processed and adjusted by various circuits. The final standard signal can be sent to video recorders and other recording media for recording, or spread through a propagation system, or sent to a monitor for display.

Baidu encyclopedia-autofocus