Lens characteristics with different focal lengths

The characteristics of lenses with different focal lengths mainly refer to: 1, and the change of viewing angle and depth of field obtained through the lens. For example, 50mm and 85mm can shoot a person from head to toe, just adjust the shooting distance, and the 50mm lens should be closer. The difference between the obtained films is the different background angle and the different degree of background blur, that is, the different depth of field. 2. Because of different angles of view, the film shot by wide-angle lens has more visual impact; The medium telephoto lens has a feeling of the scene before and after compression, and the background blur highlights the characteristics of the subject.