An optical printer is a device consisting of one or more film projectors

Movie projector

A movie projector is an opto-mechanical device for displaying moving pictures by projecting them on a projection screen. Most of the optical and mechanical elements, except for the illumination and sound devices, are present in movie cameras.-Physiology:...

 mechanically

Machine

A machine manages power to accomplish a task, examples include, a mechanical system, a computing system, an electronic system, and a molecular machine. In common usage, the meaning is that of a device having parts that perform or assist in performing any type of work...

 linked to a movie camera

Movie camera

The movie camera is a type of photographic camera which takes a rapid sequence of photographs on strips of film which was very popular for private use in the last century until its successor, the video camera, replaced it...

. It allows filmmakers to re-photograph

Photograph

A photograph is an image created by light falling on a light-sensitive surface, usually photographic film or an electronic imager such as a CCD or a CMOS chip. Most photographs are created using a camera, which uses a lens to focus the scene's visible wavelengths of light into a reproduction of...

 one or more strips of film. The optical printer is used for making special effects for motion pictures, or for copying and restoring old film material.

Common optical effects include fade outs and fade ins, dissolves, slow motion, fast motion, and matte

Matte (filmmaking)

Mattes are used in photography and special effects filmmaking to combine two or more image elements into a single, final image. Usually, mattes are used to combine a foreground image with a background image . In this case, the matte is the background painting...

 work. More complicated work can involve dozens of elements, all combined into a single scene.

History

The first, simple optical printers were constructed early in the 1920s. Linwood G. Dunn

Linwood G. Dunn

Linwood G. Dunn, A.S.C. was a pioneer of visual special effects in motion pictures and inventor of related technology...

 expanded the concept in the 1930s, and the development continued well into the 1980s, when the printers were controlled with minicomputer

Minicomputer

A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...

s. Prime examples of optical printing work include the matte

Matte (filmmaking)

Mattes are used in photography and special effects filmmaking to combine two or more image elements into a single, final image. Usually, mattes are used to combine a foreground image with a background image . In this case, the matte is the background painting...

 work in 2001: A Space Odyssey

2001: A Space Odyssey (film)

2001: A Space Odyssey is a 1968 epic science fiction film produced and directed by Stanley Kubrick, and co-written by Kubrick and Arthur C. Clarke, partially inspired by Clarke's short story The Sentinel...

and Star Wars

Star Wars Episode IV: A New Hope

Star Wars Episode IV: A New Hope, originally released as Star Wars, is a 1977 American epic space opera film, written and directed by George Lucas. It is the first of six films released in the Star Wars saga: two subsequent films complete the original trilogy, while a prequel trilogy completes the...

.

In the late 1980s, digital compositing

Digital compositing

Digital compositing is the process of digitally assembling multiple images to make a final image, typically for print, motion pictures or screen display...

 began to supplant optical effects. By the mid-nineties, computer graphics had evolved to rival and surpass what was possible with optical printers, and optical printing is now all but gone. Improvements in film scanners

Motion picture film scanner

A motion picture film scanner is a device used in digital filmmaking to scan original film for storage as high-resolution digital intermediate files.A film scanner scans original film stock: negative or positive print or reversal/IP...

 and recorders

Film recorder

A Film Recorder is a graphical output device for transferring digital images to photographic film.All film recorders typically work in the same manner. The image is fed from a host computer as a raster stream over a digital interface...

 allow for a complete feature film to be processed by computers, have special effects applied, and then be processed back to film.

Today, optical printing is mostly used as an artistic tool by experimental film

Experimental film

Experimental film or experimental cinema is a type of cinema. Experimental film is an artistic practice relieving both of visual arts and cinema. Its origins can be found in European avant-garde movements of the twenties. Experimental cinema has built its history through the texts of theoreticians...

 makers, or for educational purposes. As a technique, it is particularly useful for making copies of hand painted or physically manipulated film.

Artifacts

As in any analog process, every optical "pass" degraded the picture, just like a photocopy of a photocopy. Also, since a new, different piece of negative was exposed and printed, matching the exact colors of the original was a problem. For economical reasons, especially in the 1950s and later in TV series produced on film, printer work was limited to only the parts of a scene needing the effect. The original footage was spliced mid-shot with the optically-printed portion, resulting in an obvious change in image quality when the transition occurs.

Other problematic artifacts depend on the effect attempted, most often alignment inaccuracies in matte

Matte (filmmaking)

Mattes are used in photography and special effects filmmaking to combine two or more image elements into a single, final image. Usually, mattes are used to combine a foreground image with a background image . In this case, the matte is the background painting...

 work. For this reason, shots intended to be manipulated via optical printer were often shot on larger film formats than the rest of the project. Larger film (such as the Vistavision

VistaVision

VistaVision is a higher resolution, widescreen variant of the 35mm motion picture film format which was created by engineers at Paramount Pictures in 1954....

 format) has better clarity and less grain when reprinted and also reduces alignment problems.

See also

• Bipack
  Bipack
  In cinematography, bipacking, or a bipack, is the process of loading two reels of film into a camera, so that they both pass through the camera gate together...
  
  
• Rear projection
• Schüfftan process
  Schüfftan process
  The Schüfftan process is a movie special effect named after its inventor, Eugen Schüfftan . It was widely used in the first half of the 20th century before being almost completely replaced by the travelling matte and bluescreen effects....
  
  
• Special effect
  Special effect
  The illusions used in the film, television, theatre, or entertainment industries to simulate the imagined events in a story are traditionally called special effects ....
  
  
• Traveling matte