What do A and M on the lens of SLR camera stand for respectively?

The letter a stands for autofocus, which is the aperture priority mode. That is to say, an aperture is set, and the camera automatically gives the appropriate exposure time according to the light at that time.

The letter M stands for manual focusing and manual control mode, that is, how many apertures and exposure time need to be used are completely determined by the user, and the photos to be taken are completed in the original way regardless of the external environment.

Among them, SLR cameras also have three common exposure modes:

P file is a program automatic exposure file, just like A file. The difference is that P file only automatically sets the shutter speed and aperture value. You can adjust the focusing mode, whether to turn on the built-in flash, sensitivity and so on.

TV file is an automatic exposure file with shutter priority. After setting the shutter speed, the camera will automatically adjust the aperture value to get the correct exposure. The higher the shutter speed, the more dynamic images can be captured and it is not easy to blur.

Av file is an automatic exposure file with aperture priority. After setting the aperture value, the camera will automatically adjust the shutter speed to get the correct exposure. Using this file can reflect different depth of field changes, that is, the background blur is different, the larger the aperture (f/), the smaller the value, and the more blurred the background.

Extended data

Imaging mode of SLR camera;

The full name of a SLR camera is a single-lens reflex camera, which refers to a camera that uses a single lens, through which light shines on the reflector and takes a view through reflection.

The so-called "single lens" means that the photographic exposure light path and the framing light path * * * use one lens, unlike the paraxial camera or the double-reflex camera, the framing light path has an independent lens. "Reflection" means that a plane mirror in the camera separates the two light paths: when the mirror falls during framing, it reflects the light of the lens to the pentaprism and then to the framing window; When shooting, lift the reflector quickly, and the light can shine on the film or photosensitive element CMOS or CCD.

Baidu encyclopedia-SLR camera