Help photographers: how to calculate the depth of field of SLR lenses? All I know is that the depth of field behind the focus is twice that in front of the focus. Use a different

What is depth of field? A: In principle, there is an allowable diffusion circle before and after the far focus and the near focus, and the range between them is called the depth of field. That is to say, before and after focusing, the image still has a clear range, and the depth of the subject before and after controls the blur degree of the image on the photosensitive element. The distance between aperture, lens and subject is an important factor affecting the depth of field. The larger the aperture, the smaller the depth of field, and the smaller the aperture, the greater the depth of field. The longer the focal length of the lens, the smaller the depth of field, and vice versa. 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. In order to highlight the subject, many people will choose a small depth of field. Of course, if you want to shoot the scenery, we would recommend choosing a large depth of field. Does the depth of field of the camera matter? Is the depth of field to achieve clear subject and other blurred effects? SLR cameras are much more expensive than ordinary cameras. If the depth of field effect is achieved through post-production, wouldn't it cost less and have the same effect? Answer: The depth of field is the clear range of depth of field when shooting. The depth of field is short when the aperture is large, and all SLR cameras currently on sale can basically achieve a better shallow depth of field. In addition, the depth of field is mainly the technical standard to measure the lens, not the absolute standard to measure the art of photography. Post-production photos can't get that absolutely natural effect. Depth of field calculation formula

The depth of field calculation formula can help you understand the depth of field range of various lenses, various apertures and various lenses. This formula is aimed at the fuzzy circle you require, so the calculated depth of field range is more accurate and reliable. Of course, this is much more troublesome than Jing Shenbiao in the camera and Jing Shenbiao in the book.

The depth of field calculation formula is as follows:

Height × depth

Depth of field near the limit = ————

H+D-F H×D

The far-reaching boundary of the scenery = ————

H-D-F

H = hyperfocal distance D = focal length (the distance from the front node of the lens to the object) F = focal length of the lens.

For more information, please refer to or calculate the hyperfocal distance in Section 4.

Let's take an example to illustrate the calculation of this formula: For a 50mm(0.05 m) lens, the hyperfocal distance distance of f8 is 6.25 m (the blur circle standard is 0.05mm), and when focusing for 4 m, the depth of field of f8 is as follows:

Height× depth 6.25×4 25

Depth of field near the limit =——————— = = 2.45 (m)

h+D-F 6.25+4-0.05 10.2h×D 6.25×4 25

The far boundary of the scenery = ———————————————— = —— = —— =11.36 (m)

High density fiberboard 6.25-4-0.05 2.2

Therefore, the depth of field in this example is 2.45- 1 1.36 meters.