Calculation of photographic depth of field

1, the relationship between depth of field and aperture

Depth of field is closely related to aperture. When we open the aperture of the camera, we are actually narrowing the depth of field, and vice versa-this is an inviolable "iron law": the larger the aperture, the smaller the depth of field; The smaller the aperture, the greater the depth of field.

2. The relationship between depth of field and focal length

The depth of field is also closely related to the focal length of the camera lens. For example, compared with the fixed-focus lens of 100mm, the fixed-focus lens of 50mm definitely has a greater depth of field than the fixed-focus lens of 100mm-this is also an inviolable "iron law": the longer the focal length, the smaller the depth of field; The shorter the focal length, the greater the depth of field.

Extended data

Chinese expression of depth of field formula;

Depth of field = (2× the diameter of the diffusion circle× the square of lens focal length× the aperture value× the square of focal length)/(the fourth power of lens focal length-the square of the diameter of the diffusion circle× the square of aperture value× the square of focal length)

Depth of field on the back = (diameter of diffusion circle × aperture value × square of focusing distance)/(square of lens focal length-diameter of diffusion circle × aperture value × focusing distance)

Foreground depth = (Diffuse circle diameter× aperture value× focal length square)/(Lens focal length square+Diffuse circle diameter× aperture value× focal length)