Racking focus in filmmaking

Filmmaking

Filmmaking is the process of making a film, from an initial story, idea, or commission, through scriptwriting, casting, shooting, directing, editing, and screening the finished product before an audience that may result in a theatrical release or television program...

 and television production is the practice of shifting the attention of a audience

Audience

An audience is a group of people who participate in a show or encounter a work of art, literature , theatre, music or academics in any medium...

 of a film or video by changing the focus

Focus (optics)

In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge. Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by...

 of the lens

Photographic lens

A camera lens is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.While in principle a simple convex lens will suffice, in...

 from a subject in the foreground to a subject in the background, or vice versa. It dated back to the time when cameras did not have reflex lenses so the operator would have to "rack focus" the camera by looking through the viewfinder

Viewfinder

In photography, a viewfinder is what the photographer looks through to compose, and in many cases to focus, the picture. Most viewfinders are separate, and suffer parallax, while the single-lens reflex camera lets the viewfinder use the main optical system. Viewfinders are used in many cameras of...

, then sliding the camera over so that the shot would be in focus. The technique can be seen in as early as 1929 in the early talking picture Applause (film)

Applause (film)

Applause is a 1929 black-and-white backstage musical film, shot during the early years of sound films. It is very notable as one of the few films of its time to break free from the restrictions of sound technology. Based on a novel by Beth Brown, the film was staged and directed by Rouben...

, directed by Rouben Mamoulian. American director Richard Rush

Richard Rush (director)

Richard Rush is an American movie director, scriptwriter, and producer. He is best known for the Oscar-nominated The Stunt Man. His other works, however, have been less celebrated. The next best-known of his movies is Color of Night — also nominated, but in this case for the Golden Raspberry Award...

 claims that he and cinematographer

Cinematographer

A cinematographer is one photographing with a motion picture camera . The title is generally equivalent to director of photography , used to designate a chief over the camera and lighting crews working on a film, responsible for achieving artistic and technical decisions related to the image...

 Laszlo Kovacs

László Kovács (cinematographer)

László Kovács, A.S.C. was a Hungarian cinematographer who was influential in the development of American New Wave films. Most famous for his award-winning work on Easy Rider and Five Easy Pieces, Kovács was the recipient of numerous awards, including three Lifetime Achievement Awards...

 invented the technique, first used in the 1968 motorcycle film The Savage Seven. Rush owns the patent on a lens used in the technique.