What are the factors that affect the depth of field and explain them?

What are the factors affecting the depth of field? The depth of field varies with the focal length, aperture value and shooting distance of the lens. There are three factors that affect the depth of field. 1. The depth of field is inversely proportional to the length of the focal length, that is, the longer the focal length of the lens, the shorter the depth of field. 2. The depth of field is proportional to the distance of the object. The closer the digital camera is to the scene, the shorter the depth of field. 3. The depth of field is inversely proportional to the aperture series. The larger the aperture, the shorter the depth of field when the focal length of the lens and the shooting distance of the object remain the same. Through the above understanding of the depth of field, we can conclude that the visual angle of human eyes watching far and near scenes (expressing the perspective law of screen space with lines) has the following laws. 1. People think that the size of an object changes with the distance. The closer you get, the farther you get, and the farthest point will disappear on the horizon. 2. Lines formed by regular arrangement or parallel lines get closer and closer, gather as far away as possible, and finally converge to one point and disappear on the horizon.