What is depth of field technology? What concept?

When the camera focuses on A, not only A is clear after taking pictures, but also objects at a certain distance (b) in front of A (between A and the camera) and objects at a certain distance (c) behind A. b+c is called depth of field.

Using depth of field to obtain the required photos is called depth of field technology. General tourist scenery photos are often used, such as taking pictures in the promenade, where the pillars in front of the characters are clear and the pillars behind the characters are clear. Depth of field technology is very important in landscape photography.

The range of depth of field (b+c) is closely related to the lens form. Fixed focus lens and zoom lens, under the same focal length, the fixed focus scene is much larger than zoom. The longer the focal length, the shorter the depth of field. The smaller the aperture (that is, the larger the aperture value), the longer the depth of field.

The antonym of depth of field is background blur.