Photographic depth of field

Aperture, the distance between the lens and the subject are important factors affecting the depth of field;

1, the larger the aperture (the smaller the aperture value f) and the shallower the depth of field, the smaller the aperture (the larger the aperture value f) and the deeper the depth of field.

2. The longer the focal length of the lens, the shallower the depth of field, and vice versa.

3. The closer the subject is, the shallower the depth of field is, and the farther the subject is, the deeper the depth of field is.

After focusing, the range before and after focusing, that is, the clear image presented in the range of front and rear distance, is called depth of field.

There is a certain length of space in front of the lens (before and after focal length adjustment). When the subject is located in this space, its imaging on the negative is just between the two diffusion circles before and after focusing.

The length of the space where the subject is located is called the depth of field. In other words, the blur of the image presented by the subject on the negative plane of this space is within the limited range of the allowable circle of dispersion, and the length of this space is the depth of field.

Extended data:

Factors affecting depth of field:

1, lens focal length

2. The distance of the subject

3, the size of the aperture

4. The size of the photosensitive element (related to the radius of the allowable dispersion circle)

This relationship is:

1, the larger the aperture, the smaller the depth of field, and the smaller the aperture, the greater the depth of field.

2. The longer the focal length of the lens, the smaller the depth of field, and vice versa.

3. The closer the subject is, the smaller the depth of field is, and the farther the subject is, the greater the depth of field is.

Baidu encyclopedia-depth of field