What does depth of field mean?

Depth of field refers to the distance range of an object measured along the axis of an imager, which can obtain a clear image in front of a camera lens or other imager.

1, for details

When the lens of a camera is clearly focused on an object, a fairly clear image can be formed on the film or receiver at a point on the same plane perpendicular to the lens axis and opposite to the lens center.

Points in a certain range before and after this plane can also form clearer image points acceptable to human eyes along the lens axis. The distance between all the scenes before and after this plane is called the depth of field of the camera.

2. Factors affecting the depth of field

The distance between aperture, lens and subject is an important factor 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. The formula for calculating the depth of field can be seen from the formula that the back depth of field is >; The prospect is far-reaching.

(4) Lens aperture: The larger the aperture, the shallower the depth of field; The smaller the aperture, the deeper the depth of field; (5) Lens focal length: The longer the lens focal length, the shallower the depth of field; The shorter the focal length, the deeper the depth of field.

(6) Distance between subject and background: Changing the distance between subject and background will not change the depth of field, but only determine whether and to what extent the background is blurred. (7) Distance between the subject and the lens: The farther the distance, the deeper the depth of field; The closer the distance (not less than the minimum shooting distance), the shallower the depth of field.

The role of depth of field:

1, highlighting the theme

By controlling the depth of field, the subject can be kept clear in the picture, while the surrounding environment becomes blurred, thus highlighting the subject and enhancing the expressive force of the theme. This includes the arrangement of subject position, the choice of focus and the choice of foreground background in composition.

Step 2 create a checkpoint

Depth of field can help create a sense of layering in shooting. By adjusting the depth of field, you can choose which parts are clear and which parts are fuzzy, thus enhancing the layering of the picture. This is the most common role of depth of field in photography.

3. Enhance artistic sense

Depth of field can take very artistic photos, especially when shooting portraits, flowers, animals and other subjects. By controlling the depth of field, you can take very beautiful photos.

Step 4 simplify the picture

By controlling the depth of field, you can simplify the elements in the shooting scene, thus making the picture more concise and clear. This is a practical function. For example, in the face of some messy shooting environment, you can shoot with a large aperture to make the depth of field of the photo shallow and weaken the environment.