Friends in photography, under what circumstances are Af-A, AF-s and AF-C used respectively?

Suitable for single autofocus, used to shoot still objects. During shooting, the camera focuses once by pressing the shutter half, and the focal length is locked. Press the shutter to shoot. ?

2、AF-C:

Suitable for continuous autofocus and shooting moving objects. During shooting, the shutter camera can be released at any time for continuous focusing. ?

3、AF-A:

Suitable for automatic servo autofocus, when the camera automatically judges the mobility of the shooting object, choose AF-S or AF-C mode. When shooting sports, it will focus continuously, and when shooting static, it will focus once.

Extended data:

Tip for locking focus:

1. Use Focus Lock

First, put the subject in the middle of the viewfinder. Then press the shutter button halfway to lock the focus on the subject. When you press this button, you will hear a click or see the focus indicator (usually a green dot) on the LCD screen light up.

2. Adjust the exposure when using focus lock.

After locking the focus of the subject, the camera will also set the exposure for the subject. In other words, if the focus is locked on a very bright object, the camera will underexpose the whole photo in order to correctly expose the subject. The effect is that the whole photo looks a little dark.

3. Focus, metering and shutter button (shutter button for short, or shutter)

Shutters of SLR cameras can be divided into half-press and full-press. Under normal circumstances, when the shutter is half pressed, the camera will automatically focus and start the metering system for metering. After focusing successfully, fully pressing the shutter will release the shutter for shooting. So I call it "focus, metering and shutter release button" here.

Baidu Encyclopedia-Focus Mode