In
cinematographyCinematography , is the making of lighting and camera choices when recording photographic images for the cinema. It is closely related to the art of still photography...
,
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. It was used both for
in-camera effectAn in-camera effect is any special effect in a video or movie that is created solely by using techniques in and on the camera and/or its parts. The in camera effect is defined by the fact that the effect exists on the original camera negative or video recording before it is sent to a lab or modified...
s (effects that are nowadays mainly achieved via optical printing) and as an early subtractive colour process.
Eastman-People:* Carole Eastman* Charles Eastman, Native American physician* Crystal Eastman* David Eastman, Australian convicted murderer* Don Eastman* George Eastman, founder of Kodak* George Eastman , Italian actor* Howard Eastman* Joseph Bartlett Eastman...
, Agfa, Gevaert, and
DuPontE. I. du Pont de Nemours and Company , commonly referred to as DuPont or Du Pont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont is currently the world's second largest chemical company in terms of market capitalization and...
all manufactured bipack film stock for use as a colour process from 1920s onwards.
In
cinematographyCinematography , is the making of lighting and camera choices when recording photographic images for the cinema. It is closely related to the art of still photography...
,
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. It was used both for
in-camera effectAn in-camera effect is any special effect in a video or movie that is created solely by using techniques in and on the camera and/or its parts. The in camera effect is defined by the fact that the effect exists on the original camera negative or video recording before it is sent to a lab or modified...
s (effects that are nowadays mainly achieved via optical printing) and as an early subtractive colour process.
Use as a colour process
Eastman-People:* Carole Eastman* Charles Eastman, Native American physician* Crystal Eastman* David Eastman, Australian convicted murderer* Don Eastman* George Eastman, founder of Kodak* George Eastman , Italian actor* Howard Eastman* Joseph Bartlett Eastman...
, Agfa, Gevaert, and
DuPontE. I. du Pont de Nemours and Company , commonly referred to as DuPont or Du Pont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont is currently the world's second largest chemical company in terms of market capitalization and...
all manufactured bipack film stock for use as a colour process from 1920s onwards. Two strips of film, one
orthochromaticOrthochromatic refers to any spectrum of light that is devoid of red light.- Orthochromatic photography :Orthochromatic photography refers to a photographic emulsion that is sensitive to only blue and green light, and thus can be processed with a red safelight. Using it, blue objects appear lighter...
with a red dyed base, and one
panchromaticPanchromatic film is a type of black-and-white photographic film that is sensitive to all wavelengths of visible light. A panchromatic film therefore produces a realistic image of a scene. Almost all modern photographic film is panchromatic, but some types are orthochromatic and are not sensitive...
, would be exposed with the emulsion layers in contact with each other, resulting in one of the two negatives being reversed. As these negatives were frequently contact printed onto
duplitized filmDuplitized film stock was a type of film available through various companies used in color photography and special effects. It was introduced in the early 1910s. The stock was of standard gauge and thickness, but carried an emulsion on each side of the base. For a color process such as Cinecolor...
for toning processes such as those commencing with
PrizmaThe Prizma Color system was a technique of color motion picture photography, invented in 1913 by William Van Doren Kelley and Charles Raleigh. Initially, it was a two-color additive color system, similar to its predecessor, Kinemacolor...
, this worked to the advantage of the laboratory.
Early colour processes such as
PrizmacolorThe Prizma Color system was a technique of color motion picture photography, invented in 1913 by William Van Doren Kelley and Charles Raleigh. Initially, it was a two-color additive color system, similar to its predecessor, Kinemacolor...
,
MulticolorMulticolor is a subtractive natural color process for motion pictures. Multicolor, introduced to the motion picture industry in 1929, was based on the earlier Prizma Color process, and was the forerunner of Cinecolor....
,
CinecolorCinecolor was an early subtractive color-model two color film process, based upon the Prizma system of the 1910s and 1920s and the Multicolor system of the late 1920s and 1930s. It was developed by William T. Crispinel and Alan M...
, and
TrucolorTrucolor was a process used and owned by Consolidated Film Industries division of Republic Pictures. Trucolor was originally a two-strip process based on the earlier work of William Van Doren Kelley's Prizma color process. It later became a three-color process.Republic used Trucolor mostly for its...
all used bipack film.
The most famous version of Technicolor, the full-colour three-strip Technicolor Process 4 used from 1932 to 1954, exposed two of the three strips—the blue and red images—in bipack.
Use as an in-camera effect
To achieve the in-camera effect, a reel would be made up of pre-exposed and developed film, and unexposed raw film, which would then be loaded into the camera. The exposed film would sit in front of the unexposed film, with the emulsion of both films touching each other, causing the images on the exposed film to be contact-printed onto the unexposed stock, along with the image from the camera lens. This method, in conjunction with a static matte placed in front of the camera, could be used to print angry storm clouds into a background on a studio set. The process differs from
Optical Printing in that no optical elements (lenses, field lenses, etc) separate the two films. Both films are sandwiched together in the same camera and make use of a phenomenon known as
contact printing.
The process had its beginnings in providing a repeatable method of compositing live action and matte paintings, allowing the painted section of the final image to be completed later, and not tying up the set/sound-stage whilst the artist matched the painting to the set. It also alleviated the considerable difficulties caused by matching shadows on the painting to the set on an open-air set. The process worked equally well for matting-in real water to a model, or a model skyline to live action. The process was also referred to as the
Held Take process. Perhaps the most famous example of a
held take is the long shot of astronauts clambering down into a lunar excavation in
2001: A Space Odyssey2001: A Space Odyssey is a 1968 science fiction film directed by Stanley Kubrick and written by Kubrick and Arthur C. Clarke...
.
The technique, if used with a camera not specially designed for contact printing, runs the risk of jamming the camera, due to the double thickness of film in the gate, and damaging both the exposed and unexposed stock. On the other hand, because both strips of film are in contact and are handled by the same film transport mechanism at the same time, registration is kept very precise. Special cameras designed for the process were manufactured by Acme and Oxberry, amongst others, and these usually featured an extremely precise registration mechanism specially designed for the process. These
process cameras are usually recognisable by their special film magazines, which look like two standard film magazines on top of each other. The magazines allow the separate loading of exposed and unexposed stock, as opposed to winding the two films onto the same reel.
The bipack process, which is a competing method to
optical printingAn optical printer is a device consisting of one or more film projectors mechanically linked to a movie camera. It allows filmmakers to re-photograph one or more strips of film...
, was used until digital methods of compositing became predominant in the industry.
Industrial Light and MagicIndustrial Light & Magic is an Academy Award winning motion picture visual effects company that was founded in May 1975 by George Lucas and is owned by Lucasfilm. Lucas created the company when he discovered that the special effects department at 20th Century Fox was shut down after he was given...
used a specially-built rig, built for
The Empire Strikes Back that utilised the method to create matte painting composites.
The Dunning Process
Various improvements and extensions of the process followed, the most famous being Carroll D. Dunning's, an early method built on the bipacking technique and used for creating traveling mattes. It is described thus:
- The foreground action is lighted with yellow light only in front of a uniform, strongly lighted blue backing. Panchromatic negative film is used in the camera as the rear component of a bipack in which the front film is a positive yellow dye image of the background scene. This yellow dye image is exposed on the negative by the blue light from the backing areas, but the yellow light from the foreground passes through it and records an image of the foreground at the same time.
The Dunning Process, often in shorthand referred to as "process," was used in many black and white films, most notably
King KongKing Kong is a fictional movie monster that has appeared in several films since 1933. These include the groundbreaking 1933 film King Kong, the film remakes of 1976 and 2005, as well as various sequels...
. Its chief limitation was that it could not be used for colour cinematography, and the process died out with the increasing move toward production of films in colour.
See also
- Optical printer
An optical printer is a device consisting of one or more film projectors mechanically linked to a movie camera. It allows filmmakers to re-photograph one or more strips of film...
- 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
The illusions used in the film, television, theater, or entertainment industries to simulate the imagined events in a story are traditionally called special effects ....
- Traveling matte