What is the depth of field lens in the movie?

In optics, especially video or photography, depth of field? (DOF) is the range of distances that can be clearly imaged in space.

Depth of field is the range of good focus. It can highlight the subject by blurring the background, and can also shoot a clear background.

Three determinants of depth of field:

1, lens focal length

2. The distance of the subject

3. The size of the aperture.

The shorter the focal length of the lens, the wider the range of depth of field, the smaller the aperture and the greater the depth of field. A super wide-angle lens has a great depth of field at almost all apertures. Even with the smallest aperture, the depth of field of telephoto lens is very limited. Some single-lens reflex cameras have a depth of field prediction button, so you can predict the depth of field before pressing the shutter.

Extended data:

There are usually three reasons that affect the depth of field:

1. The larger the aperture, the shorter the depth of field, and the smaller the aperture, the longer the depth of field.

When the shooting distance is constant, when shooting with a small aperture, the clear range of the scene before and after the subject will become longer because of the larger depth of field. When a large aperture is used, the clear range of the scene before and after the subject will be shortened.

2. The longer the focal length, the shorter the depth of field, the shorter the focal length and the longer the depth of field.

When the aperture and shutter are the same, shooting the same scene and using a long lens will make the depth of field shallow. When using a wide-angle lens, the depth of field will be longer.

Using a long lens on the left and a wide-angle lens on the right can show the difference in depth of field.

3. The closer to the subject, the shallower the depth of field, and the farther away from the subject, the longer the depth of field.

With the aperture, shutter and lens focal length unchanged, the closer you are to the subject, the shallower the depth of field will be. The farther away from the subject, the longer the depth of field.

Baidu encyclopedia-depth of field lens