The role of depth of field lens

The function of depth of field lens is mainly reflected in three aspects: highlighting the main body of the character and showing the details; Show environmental relations, three-dimensional; Enhance the artistic effect and sublimate the film.

1, highlighting the main body of the characters and showing the details.

Under the depth-of-field lens, the camera usually has a large aperture and a blurred background. People or things in the foreground will easily stand out, and this visual feast will make the picture have a deeper sense of space. Virtual reality will support the characteristics of the subject, make the picture look clean and lively, bring easy-to-distinguish subject information to the audience, and increase the visual impact. For example, in the mountain scene of Bo Huang in the movie "The Island", the depth of field lens is used to highlight the main center of the character and show the messy details on his face.

2, show the environmental relationship, three-dimensional.

In the depth-of-field lens, the relationship between people and the environment is usually inseparable. Most people's real focus is the subject, and the virtual focus of the environment is the object. There is a virtual reality between the two, which makes it easier to show the environmental relationship between people and things in series, strengthens the depth and reduces the content of the picture. In Citizen Kane, the mother is filmed discussing Kane's future, and the depth of field gradually moves to Kane, who is playing with snow behind him, to show the relationship between the environments.

3. Enhance the artistic effect and sublimate the film.

In depth-of-field lens, large depth of field is used to highlight the subject and small depth of field is used to show the details. As a film language, the depth of field lens conforms to the functions of recording and prompting, shows the artistic effect of the film and enhances the expressive force. Sublimate the texture of the film and the picture, and the depth of field lens can help the audience understand the video picture more intuitively and enrich the film information. For example, in the movie The Battle of Changjin Lake, the scene of the Red Army eating frozen potatoes was filmed, and a series of depth-of-field shots were used to enhance the artistic effect of the picture.

About depth of field lens

The depth-of-field lens highlights the subject by blurring the background, and can also shoot a clear background. In optics, especially in video recording or photography, the depth of field is the distance range that can be clearly imaged in space.

Generally speaking, the shorter the focal length of the lens, the larger the range of depth of field, the smaller the aperture and the greater the depth of field. A super wide-angle lens has a great depth of field at almost all apertures. Even with the smallest aperture, the depth of field of telephoto lens is very limited. Some single-lens reflex cameras have a depth of field prediction button, so you can predict the depth of field before pressing the shutter.

When the shooting distance is constant, when shooting with a small aperture, the clear range of the scene before and after the subject will become longer because of the larger depth of field. When a large aperture is used, the clear range of the scene before and after the subject will be shortened. With the aperture, shutter and lens focal length unchanged, the closer you are to the subject, the shallower the depth of field will be. The farther away from the subject, the longer the depth of field.