The depth of field behind the focus is twice that in front of the focus. What do you mean?

That is to say, the distance between the front n meters and the back 2n meters of the subject can be clearly imaged. (n stands for deep prospect)

Depth of field is the range of good focus. It can decide whether to blur the background to highlight the subject or shoot a clear background. People can often see the blurred background in photos such as flowers and insects. However, when taking commemorative photos, group photos, scenery and other photos, the background will generally be as clear as the subject.

The car in the photo is as clear as the background, which is called depth of field. Only the car in the photo is clear and the background is blurred. This is called depth of field. The easiest way to adjust the depth of field is to change the aperture size. If you make the aperture bigger, the depth of field will be shallower, and vice versa. Of course, the larger the aperture, the faster the shutter speed, the smaller the aperture and the slower the shutter speed. In this way, photos with different depth of field can be obtained under the same exposure intensity.

Aperture is not the only factor that affects the depth of field. Short shooting distance leads to the depth of the scene, long shooting distance leads to the depth of the scene, and short shooting distance leads to the opposite. Therefore, when shooting with a wide-angle lens, it is easy to focus on the whole image, while when shooting with a telephoto lens, attention should be paid because the depth of field is shallow. Similarly, based on the point with good focus, the point near it is deeper than the far point.

The scene on the plane where the focus subject is located will form a clear image on the film, and there is a range from somewhere in front to somewhere behind it, in which all the scenes can form a clear image. This range is called depth of field.

There is a circle of symmetrical aperture scale on the camera lens, which is called Jing Shenbiao. You can point out the clear distance range before and after the subject.

The depth of field varies with the set aperture value: large aperture depth of field is short and small aperture depth of field is long. The depth of field will also change with the distance of the subject. When the lens focuses on close range, the depth of field is short, and when focusing on distant objects, it is long.

If you need a large depth of field, you should first choose a smaller aperture and use a slower shutter to ensure proper exposure. On the contrary, if you need to highlight the theme with a small depth of field, use a large aperture and be fast. When the object is stationary, the speed can be set slower and a smaller aperture can be selected; When shooting a moving object, in order to avoid image blur, you should choose one with fast speed and large aperture.