Motion Picture

I INTRODUCTION

Motion Picture, a series of images that are projected onto a screen to create the illusion of motion. Motion pictures—also called movies, films, or the cinema—are one of the most popular forms of entertainment, enabling people to immerse themselves in an imaginary world for a short period of time. But movies can also teach people about history, science, human behavior, and many other subjects. Some films combine entertainment with instruction, to make the learning process more enjoyable. In all its forms, cinema is an art as well as a business, and those who make motion pictures take great pride in their creations.

The images that make up a motion picture are all individual photographs. But when they appear rapidly in succession, the human eye does not detect that they are separate images. This results from persistence of vision, a phenomenon whereby the eye retains a visual image for a fraction of a second after the source has been removed. Although we do not experience the images as individual photographs, we do notice the differences between them. The brain then perceives these differences as motion.

Motion pictures are recorded using specially designed cameras that capture the images on rolls of film. After being processed and printed, the film is run through a projector, which shines light through the film so that the images are displayed on a screen. Most movies have accompanying sound.

This article concerns the technical aspects of motion-picture production. For information about the artistic and historical development of motion pictures and the motion-picture industry, see Motion Pictures, History of.

II TYPES OF MOTION PICTURES

There are many types of motion pictures, but the most significant categories are feature films, animated films, documentaries, experimental films, industrial films, and educational films.

Feature films are the movies most commonly shown in large movie theaters. They typically last at least one and one-half hours and tell a fictional story or a story based on real events but portrayed by actors. The list of prominent feature films is far too long to recount in this article, but some of the best-known include The Birth of a Nation (1914), Metropolis (1926), Citizen Kane (1941), Casablanca (1942), On the Waterfront (1954), The Sound of Music (1965), The Godfather (1972), Star Wars (1977), Gandhi (1982), Jurassic Park (1993), and Titanic (1997).

Animated movies follow the same format as features, but use images created by artists. These films create the illusion of movement from a series of two-dimensional drawings, three-dimensional objects, or computer-generated images. The first animated feature was the German film Die Abenteuer des Prinzen Achmed (The Adventures of Prince Achmed, 1926). Other notable ones include Snow White and the Seven Dwarfs (1937), Dumbo (1941), Sleeping Beauty (1959), Yellow Submarine (1968), Heavy Traffic (1973), the Czech film Neco z Alenky (Alice, 1988), the Japanese film Majo no Takkyubin (Kiki's Delivery Service, 1989), Beauty and the Beast (1991), and The Lion King (1994). In some films, animated characters interact with human actors, as in Who Framed Roger Rabbit (1988). For more detailed information on animated films, see Animation.

Another form of film is the documentary, which deals primarily with fact, not fiction. Documentaries do not often appear in theaters, but they are seen regularly on cable and broadcast television. Some well-known documentaries are Nanook of the North (1922), The Silent World (1956), Harlan County, U.S.A. (1976), Eyes on the Prize (1987), and Hoop Dreams (1994).

An experimental film is a sequence of images, literal or abstract, which do not necessarily form a narrative. An experimental film can be animated, live action, computer generated, or a combination of all three. Five noteworthy experimental films are the French film Un Chien Andalou (An Andalusian Dog, 1929), Meshes of the Afternoon (1943), A Movie (1958), Eraserhead (1978), and Privilege (1991).

Industrial films are made by companies that wish to publicize their products or generate a favorable public image. Educational films are specifically intended to be shown in classrooms. Their aim is to instruct, on subjects from history to driving skills.

III THE PEOPLE WHO MAKE A MOTION PICTURE

Many different people contribute their skills and talents to the making of a film. The stars and other actors who appear on the screen are only part of the story; most of those who work on a production do not appear on camera. The most prominent roles behind the scenes are the producer, screenwriter, director, unit production manager, casting director, director of photography, designers, assistant directors, film and sound editors, and music composer. Because every film is a unique project, the roles may overlap or differ depending on the individuals involved.

A Producer

The producer is responsible for turning a film idea into a successful motion picture. The producer must find money to pay for the production, hire actors and the production team, supervise the production process, and make arrangements for distributing the finished film to theaters.

If the producer has obtained financing from a studio or film distributor, that organization may want a representative to be on hand during production. This person is called the executive producer. In addition, anyone who contributes substantially in any manner to the motion picture—with their time, money, or influence—may receive the credit of associate producer or some similar title.

B Screenwriter

Screenwriters develop original ideas for the screen or adapt previously written pieces of work as motion pictures. Adaptations may come from novels, stage plays, musicals, or many other sources. Screenwriters work in two ways. They can be commissioned to write a script or they can write a script on spec (short for “on speculation”), meaning that the screenwriter is hoping that someone will like the independently written script enough to buy the rights to it and arrange for production. Once a screenplay has been purchased, the producer may decide to have it rewritten either by the original writer or by new writers.

The first step in writing a script is to create an outline, which is a one- or two-page description of the action or plot. This is followed by a treatment, which is a detailed description of the film, containing some passages of dialogue with all the scenes sketched out and the subplots developed. Then the writer begins the script itself, which fills in all the details. It sets forth the time and place of the action, describes the characters' physical appearances, and supplies all the dialogue and action. Scripts also indicate where cameras should be positioned and what camera movements should occur while filming. Scripts indicate transition devices between scenes such as dissolves (when one image gradually replaces another), fade-ins (when an image gradually replaces the blank screen), fade-outs (when a blank screen gradually replaces the image), and straight cuts from one scene to the next.

C Director

The director analyzes the script, visualizes how the film should look, and guides the actors and the production crew as they carry out that vision. Many people imagine the director as the person who controls every aspect of film production, but the director's role is usually not quite this broad. Instead, a film is a cooperative project between the director, the producer, the actors, and the crew members. A good director balances his or her desires with other people's to produce the best film possible, while all the time remaining as true as possible to his or her initial vision.

During the production process, several factors can influence how the director's vision of the film is carried out. If negotiations with an actor break down, then another actor may have to be found for the part. If much of the film takes place outside and the weather does not cooperate, the film's settings may have to be changed. And if a key actor or crew member interprets a scene differently than the director does, the director may ultimately accept that vision of the scene. Ideally, the producer and director share a vision for the film and agree on how to make the film. (If they do not, and the differences are great, the director may be fired from the project.) When the film is ready to be edited, the director supervises the first cut (the name given to the edited film). After that, however, the producers can come in and re-edit the film, if they want. Very few directors have the right to approve the final cut of a film. See also Directing.

D Unit Production Manager

The unit production manager (UPM), who reports to the producer, is responsible for scheduling, budgeting, selecting many of the crew members, and arranging for permits from various authorities and owners to shoot at locations outside the studio. The UPM also oversees the purchase of goods and services, handles the day-to-day business of running the production office, and ensures that the project stays within its budget.

E Casting Director

The casting director selects actors and negotiates contracts during the hiring process, although the final choice—particularly when selecting stars for lead roles—usually falls to the director and the producer. When selecting actors for a film, casting directors take many factors into account, such as an actor's suitability for the role, box-office appeal, acting ability, and experience.

F Actors

The actors play the roles of the film. To create believable characters, they rely on the details in the script, the director's vision, and their own sense of the role. In most films, the actor's job is to make the audience believe that the character is a real person speaking unrehearsed lines in a natural setting. An actor normally accomplishes this through voice, movement, and the portrayal of emotion. But other artistic qualities also affect the audience's judgment. These qualities are often difficult to describe or define, but they include charm, depth of feeling, originality, plausibility, and physical appearance.

Acting is a complex art. The mastery of voice projection, various manners of speaking, gesture, movement, and other abilities is only part of the craft. Other basic acting skills include an ability to memorize lines, develop a sense of timing, and express a character's social status, age, and temperament.

G Stunt People

Many films involve actions that could result in injury. These actions may be as dramatic as jumping off a cliff or as commonplace as tripping and falling down. During many potentially dangerous scenes, specially trained stuntmen and stuntwomen fill in for the actors. This ensures that the stunt will be performed as safely as possible, and that the actors will not risk injury. Nevertheless, some stars, such as Chinese actor Jackie Chan, insist on doing their own stunts.

H Animal “Actors”

For scenes in which animals must perform, specially trained animal “actors” appear. These animals obey commands from their trainer while being filmed. In many cases, multiple animals appear in the same part, because of long hours of filming or because the animal grows or changes in appearance or in some other way during a filming schedule. Animals that act in films range from ducks to elephants. Memorable roles played by animals include the dog Lassie (in Lassie Come Home, 1943), the dog Benji (in Benji, 1974), and the pig Babe (in Babe, 1995).

I Director of Photography

The director of photography (DP), also known as the cinematographer, works closely with the director and interprets the action of the story in terms of light, shade, composition, and camera movement. Other responsibilities include selecting the type of lens to be used for a shot, which influences the appearance of the image, and determining the camera's position and angle. The DP rarely operates the camera directly; this function usually falls to a camera operator.

J Designers

The production designer, sometimes called the art director, is responsible for the set designs and the overall look of the film. In some films, creating sets involves a great deal of work. For example, a realistic Western may call for the construction of the façade of an entire main street, along with the interiors of a saloon, hotel, and other buildings. The clothing that the actors wear also contributes to the look of a film, so the costume designer is a key member of the production team. He or she designs appropriate costumes or searches out vintage clothing in stores or costume houses. Additional designers deal with lighting, makeup, and other visual aspects of the production.

K Assistant Directors

Most motion pictures have at least one assistant director (AD). The ADs assist the director in almost every task. The highest-ranking AD, called the first AD, has several duties. He or she creates the overall shooting schedule, which lists the days for filming each scene, and manages many of the day-to-day problems that arise on the set. Each day the first AD also submits the following day's call sheet (schedule for cast and crew) to the UPM and the director for approval. And the first AD works with the director during shooting, assisting in the preparation for each shot. The second AD assists the first AD by getting the cast and crew to the right places at the right times, looking after extras (people who appear in the background to lend reality to the film), and taking care of many of the details involved in preparing for the next day's filming.

L Film and Sound Editors

Motion pictures are filmed in hundreds of brief shots, which must be arranged into a final product that fulfills the vision of the director and producer. This responsibility falls to the editor. The editor first screens each day's film footage (called dailies or rushes) for the director and key members of the crew. Preparation of the dailies continues throughout the production period, meaning that the film is being edited at the same time that it is being shot. Screening the dailies enables the director and producer to choose the best shots and to decide if they need to reshoot any scenes for technical or artistic reasons. After the principal filming is done, the editor finishes the editing of the film and supervises optical effects (such as freeze-frames) and titles that are to be inserted into the motion picture.

The director, producer, or editor also may decide that parts of the film have inferior sound quality. A sound editor then re-records the actors' voices in these scenes. The actors speak the lines in the studio while viewing the scene on-screen, in a process called automatic dialogue replacement (ADR). Sound editors also add recorded sound effects to complete an environment for the film. For example, if a scene takes place on a city street, the editors may add honking horns and other appropriate background traffic noises. One of the final steps in the editing process is the preparation and mixing of the separate sound tracks so that all the tracks—dialogue, music, and sound effects—are blended together to create a seamless unified sound experience for the audience.

M Music Composer

The composer works with the director and editor to create a musical score that provides transitions between scenes and an emotional point of view for scenes and the film as a whole. Music is often used to enhance the dramatic content. For example, music can identify a person as suspicious when there is nothing visible on the screen to suggest such a characteristic.

N Other Positions

In addition to the positions listed above, many other people take part in movie production. Foley artists help create background or peripheral noises, such as footsteps. A gaffer supervises electrical work and is assisted by the best boy. The key grip supervises the grips, who set up and adjust production equipment on the set. The production sound mixer supervises the sound recording during a shoot, and the sound mixer puts together all the sound for the final track by adjusting volume, fading noises in and out, and creating any other necessary audio effects. Depending on a movie's genre and budget, it can require many other professionals, including assistants, carpenters, drivers, etiquette coaches, historical consultants, housing coordinators, medics, and so on.

IV SHOOTING A MOTION PICTURE

Most motion pictures involve the same general process. This section describes this filming process and then discusses some of the more technical aspects of filming.

A General Filming Process

A development stage precedes production. In this stage, the screenwriter writes the script and the producer hires the director and key actors, prepares a budget and shooting schedule, and raises the necessary funds to pay for the production.

The next stage, preproduction, involves the remaining preparatory work before production begins. During preproduction, the producer approves the final version of the script, the rest of the cast and crew members are hired, and shooting locations are finalized. The director, assistant director, unit production manager, and producer plan the sequence for shooting the individual scenes. If possible, the actors hold rehearsals. The producer, director, and designers work together to outline the visual look of the film—how the scenes will be staged, set construction and decoration, costumes, makeup and hair design, and lighting.

When preproduction is completed, production can begin. A movie is filmed scene by scene, and a scene is filmed shot by shot. These scenes and shots are not usually filmed in the order that they appear in the film. This is because filming depends on factors such as weather conditions, actors' availability, and the set-construction schedule. Scenes that involve large, complicated sets often are filmed near the end of the shooting schedule, because these sets take longer to be completed. Sets can be elaborate. In Titanic, for example, the filmmakers built major interior rooms such as the grand staircase and dining saloon over a 19 million liter (5 million gallon) tank of water. The sets were supported by hydraulic systems that lowered them into the water to simulate the sinking of the ship.

Preparing for a film shot involves five main operations: The art department and property master prepare the set furnishings and the props the actors will use; the actors run through their lines and movements; the director of photography selects and arranges the lights; the camera operator rehearses the various camera angles and movements to be used in the shot; and the sound crew determines the volume level and placement of microphones. The director oversees and coordinates all these activities.

Each filmed shot is called a take. For complicated shots such as battlefield sequences, the director may use multiple cameras to minimize the number of takes. Even with multiple cameras, however, the director may require many takes before he or she is satisfied. After each take the director confers with the camera operator and production sound mixer. If the director is pleased by the performances and if the camera and sound work are good, the director instructs that the take be printed. If it is not good, it is not printed.

In high-budget productions that involve complicated scenes, it is customary to film an entire sequence in one long master shot, which includes all the major action. Cover shots are brief shots that, edited into the master shot, give the scene proper dramatic emphasis and meaningful detail from moment to moment. Cover shots include close-ups, medium shots, long shots, tracking shots (shots in which the camera is moving while filming), and panning shots (shots in which the camera swivels while filming). Shooting this array of shots is called shooting coverage. Each cover shot, however minor, necessitates a new camera setup and a new placement of lights, microphones, and actors. Action from shot to shot must always match when edited into the film. For example, if the heroine has set down a glass with her left hand in the master shot, she must not set it down with her right hand in a close-up.

At the end of the day, the shots that the director likes are printed. The following day, the director, producer, cinematographer, and editor look at these dailies. During these screenings the director and editor begin to assemble shots into scenes and the scenes into a sequence. Early versions of sequences, or early cuts, often contain alternative takes for certain shots. As the director and editor make final decisions during the editing process, they eliminate the extra takes, so that the structure of the final picture emerges in the form of a rough cut. Then, as scenes are polished and transitions smoothed, the rough cut gradually becomes the first cut.

During the postproduction work, the director and editor solve problems. For example, if a shot went out of focus for a moment in a close-up, they may cover the lapse by cutting to a medium shot if they do not have another satisfactory take of the close-up. While editing the first cut, the director weighs the editor's recommendations but keeps the overall plan of the picture in mind. The producer also contributes, especially when the director and editor are considering reshooting scenes; this may cause the picture to go over budget. When all the scenes are shot and the first cut finished, the producer may approve it or work with the editor and/or the director to make further refinements. The finished product is the final cut. The film is then ready for sound editing, finalizing of the musical score, and mixing.

B Technical Aspects of Filming

The technical aspects of the filming process include operating the camera, lighting the scene, and recording the sound. Once the film has been shot, it then must be processed and printed. During this process or after it, special effects can be added to the film to create dramatic visual images. The last step in the production of a movie takes place in the film laboratory, where the visual and sound elements of the final cut are combined into a composite print. When the composite print is run through the projector, action and sound together create for the audience the vision of the story intended by the filmmaking team.

B1 Operating the Camera

The photographic process in which motion-picture film is exposed to light to create an image corresponds to conventional still photography. Camera lenses of different focal length are used as required to gain the desired perspective or photographic effect, and changing the lens aperture (opening) controls the amount of light that reaches the film. Shutter speed, which determines how long the film is exposed to light, and aperture together affect the relative lightness or darkness of the image.

The most important elements of a motion-picture camera are the lens, the shutter, and the two reels that supply the film and take it up again. When a motion-picture camera is in operation, the shutter opens and exposes the film, which receives an image formed by the lens. The shutter then closes and a mechanism called a pull-down claw moves the film along so that it can be exposed once again. In normal operation this cycle occurs 24 times per second, creating 24 separate still photos.

By operating the camera at speeds much faster or much slower than 24 frames per second, the apparent time of a motion can be lengthened or shortened. For example, filming a scene at 72 frames per second, but projecting it at the normal speed of 24 frames per second, slows down the action so that what happens in one second takes three seconds on screen. Operating the camera at a slow frame speed produces the opposite effect and is useful for viewing a very slow process, such as the growth of a plant. When a plant's growth is filmed at one frame every three hours and the film is projected at 24 frames per second, 72 hours of growth are compressed into every second, and on film the plant will appear to spring from the earth.

The steadiness of the image the camera records comes from the camera mount and a device in the camera motor called the registration pin, which holds each frame still while it is exposed to light. Three-legged stands called tripods usually support the camera, and a platform on wheels called a dolly holds the camera steady while it moves across the floor or ground. A crane or supporting arm called a boom raises and lowers the camera during filming. A Steadicam is a camera mount for producing smooth shots in places where using a dolly or crane presents difficulties, such as on a staircase. The Steadicam uses gyroscopes and other advanced electronic equipment to prevent the camera from shaking. When the filmmaker does not want the camera to be steady, the camera operator simply holds the camera in his or her hands. This technique is used in documentary films to capture a fast-moving event or in feature films to create a documentary-like feel.

B2 Lighting the Scene

A scene can be shot in a studio or on location, meaning that it is filmed in a place that has not been specially constructed for the film.

Two types of light source are used for interior shooting, whether in a studio or on location. Incandescent lamps, which range from a few watts to 10,000 watts in power, resemble household light bulbs and are used for most filming. Arc lamps are stronger and cast a wider and more direct beam of light. They are used when the crew must illuminate a large area or when the scene demands extremely bright light.

Much location shooting occurs outdoors, where unpredictable weather can make lighting difficult. Even in daylight, the film crew uses lights and reflectors to increase the brightness of the scene or to fill in patches of darkness or shadow. When the shooting environment outside is too bright, film crews use devices such as butterflies, large pieces of silk or diffusion material, to cut down on brightness or to create shadow.

Sometimes a director elects to use day-for-night shooting, in which a scene is shot during the day but made to look as if it occurred at night. To achieve this effect, the film crew must manipulate the amount of light that reaches the film. Their methods include placing the subject in shade, positioning the camera so that it does not shoot the sky, and choosing certain types of filters to place on the lens.

B3 Recording the Sound

In filmmaking, sounds are picked up by microphone and recorded on tape. During production a boom generally holds the microphone above the actors and out of camera range so that it is not seen on screen. Whenever possible, the original recording includes only dialogue. Additional sound can obscure the dialogue.

Sometimes shooting outdoors results in too much noise, rendering some of the dialogue unusable. In this case, the actors later record replacement dialogue, and their lines are then synchronized with the picture. During postproduction, sound experts create special sounds, such as a train wreck or the clinking of silverware and dishes during a dinner scene.

A complete sound track is built from tracks that have been recorded separately. The dialogue is on several tracks, the music on others, and sound effects on yet others. Many large, elaborate productions such as musicals have 30 or more separate tracks. Sound engineers combine, or mix, the individual tracks electronically in a recording studio while viewing the final cut of the picture.

B4 Motion-Picture Film

Motion-picture film is manufactured in long ribbons that are stored and handled in rolls. Perforations along the edge of the film help move it through the camera, printer, and projector at a constant speed, typically 24 frames per second. When the sound track is mixed and the visual optical effects completed, the picture and sound are printed onto one piece of film for release to theaters.

The greater a filmstrip's width, the sharper the image that is projected onto the screen. The standard width of film used for a feature-length motion picture is 35 mm (1.38 in). An occasional large-scale production appears on 70-millimeter (2.76-in) film, whereas low-budget and some experimental films are typically shot on less expensive 16-millimeter (0.63-in) film. (Filmmakers now shoot most documentaries and some experimental films on digital videotape, because its quality is almost that of film, and it is cheaper to buy and does not need to be processed.)

The film itself consists of a thin layer of light-sensitive material called an emulsion, which coats a transparent base of flexible cellulose. Most emulsions contain silver bromide suspended in gelatin. Color-film emulsion consists of three layers, each containing silver bromide along with a chemical dye sensitive to one color—red, green, or blue. During processing the images formed on the three layers combine to produce a single image on film. The exposed rolls of film pass over a series of rollers and through a developing solution, a wash, fixing baths, a second wash, and a drying chamber. Finally, the developed and dried film is rewound into a roll. (Videotape, by contrast, requires no processing. Video cameras record sound and images electronically onto magnetic tape, which can be played back immediately.)

When the emulsion is exposed to light, a latent image is formed. During processing, the developer changes the silver halide in the emulsion to metallic silver where light touched the emulsion. In the next stage of processing, the silver halide crystals that were not exposed are washed out of the emulsion by a chemical solution called the hypo or the fixer. What remains, the metallic silver, forms a negative image of the subject—darkest where the most light struck the emulsion, and lightest where the least light struck.

To make a positive image, light is passed through the negative to expose another roll of film. Where the negative is thickest, little light strikes the print film. In processing the print film, the unexposed silver halides are washed away, leaving the reverse of the negative image—a thin emulsion in the print where the negative was thick. This corresponds to the light areas of the subject. Where the subject was dark, the negative is thin and the print film thick.

C Special Effects

Special visual effects have added to the allure of motion pictures since the early days of cinema. French director Georges Méliès is considered the most influential pioneer of special effects. His film A Trip to the Moon (1902) combined live action with animation, demonstrating to audiences that cinema could create worlds, objects, and events that did not exist in real life.

Three-dimensional (3-D) film technology was developed in the early 1920s but did not become popular until the 1950s, when it enjoyed a brief period of use. Although motion-picture film, like still photography, normally yields two-dimensional images, the illusion of a third dimension can be achieved by projecting two separate movies—one made for the right eye, the other for the left—onto a special screen. Members of the audience wear 3-D eyeglasses so that the right eye sees one picture and the left eye sees the other, producing the effect of three dimensions.

Many of the special effects used in contemporary films were invented before World War II (1939-1945). For instance, in the silent film The Thief of Bagdad (1924), Douglas Fairbanks appears to battle huge monsters by means of a technique that involved filming two scenes separately, then blending them during the printing process. Half of one negative image was exposed during printing (say, the half with Fairbanks), while the other half was covered. Then the covered, still-unexposed half was exposed to the negative with the monsters. The result was a complete single image formed from two separate scenes. This same split-screen technique allowed Kevin Kline to play both the president of the United States and his look-alike in Dave (1993).

Another example of the lasting power of early techniques is stop-motion photography. The original King Kong (1933) used this technique, in which the King Kong figurine was repeatedly filmed for very brief segments and then moved, so that when the film was projected at normal speed, King Kong appeared to move. The same technique animated the figures in James and the Giant Peach (1996).

After World War II there was a lull in the development and use of special effects. Technical advances in the design and manufacture of motion-picture cameras made it easier to film on actual locations, and the trend in cinematic storytelling tended toward realism, resulting in less call for fantastic illusions. Then in 1968 the film 2001: A Space Odyssey, in which astronauts appear to float weightlessly in outer space, led to a renewed interest in special effects. Star Wars (1977) revolutionized the way special effects were created and proved them to be a potential box-office gold mine. George Lucas, who directed Star Wars, created his own special-effects studio, Industrial Light & Magic, which became a leading innovator and was responsible for a series of groundbreaking special-effects techniques.

In making Star Wars, Lucas used computers to control camera movement. In this technique, called motion-control cinematography, the computer's precise control allows a camera shooting live action in one studio to move at the same speed as a camera shooting a model in a second studio that serves as background for the live action. The two shots can be combined later with full confidence that camera moves will be identical and will therefore match seamlessly. Motion-control cinematography also allows cameras to replicate the same series of shots precisely while filming the same object. With each pass the camera makes, different elements can be added. For example, in Star Wars different engine glows and running lights could appear on the spaceships in successive filming passes. The accumulation of more and more detail results in a complex and realistic-looking object.

Many of the spaceships and other objects in Star Wars were miniatures, borrowing another technique from early cinema. Filmmakers have long used miniatures to stage such large-scale actions as the collapse of a building or a shipwreck, scenes that would be too expensive or unfeasible to stage. Adding in appropriate sound for the scale of the event completes the illusion.

Filmmakers draw upon many other special effects to create illusions in the cinema. Sometimes a film calls for an actor to appear in a place it will be difficult to film, or doing something that is impossible, such as flying. In these cases, the filmmaker uses the so-called blue-screen process, filming the actor in front of a screen that is either painted or lit to match a particular shade of blue. During printing the filmmakers then replace this blue background with a completely different image, creating the illusion that the actors are moving through that setting. In Superman (1978) and its sequels, blue-screen was used to depict the hero's flight. The actor, Christopher Reeve, was filmed with his arms outstretched against a blue screen in a studio, acting as if he were flying. After images of the city (from the perspective of a low-flying airplane) were substituted for the blue background, Superman appeared to be flying over tall buildings.

Another way to place actors in settings that do not actually exist is through matte photography. This technique involves a realistic painting with an area blacked out. The painting is filmed and then, separately, an action sequence that has been carefully framed to fit the perspective and scale of the blacked-out area is inserted. The combination of the two images creates the illusion that the action is happening in the environment of the painting. The paintings used in matte photography range widely in size, and many matte photographers are now using computers to generate the paintings. One use of matte photography occurs in the final scene of Raiders of the Lost Ark (1981). The scene shows a worker pushing a crate through a huge warehouse stocked with all kinds of government-owned objects. Except for the worker and the path he takes, the warehouse is actually a painting.

In the late 20th century, the techniques used in creating effects entered a new era, that of digitization. In digitization, sounds and images are stored as electronic files and viewed and edited on a computer. Creating a digital version of a filmed image takes a huge amount of data-storage capacity. To approximate the look of the 35-millimeter film, the computer must break each frame into millions of pixels (picture elements). The computer assigns a number value to each pixel that corresponds to a color and brightness level. By renumbering the pixels so that the colors change, the image can be altered.

Digitizing images allows them to be manipulated in almost any conceivable manner, and the computer can also be used to generate its own images. An example of combined imagery is a scene from Jurassic Park (1993) where computer-generated dinosaurs are seen charging toward and then leaping over a filmed man and two children. In Forrest Gump (1994) the title character seems to meet historical figures such as President John F. Kennedy and singer Elvis Presley. This was done by digitally merging images of lead actor Tom Hanks with films of Kennedy, Presley, and other figures.

Another popular computer-generated technique is called morphing, which is short for metamorphosis on film. Morphing, which is the featured visual effect in Terminator 2: Judgment Day (1991), involves the digital translation of one object, or character, into another. The effect is of the object or character visibly and fluidly changing into another.

Advances in digitization allowed filmmakers to alter their previous work in ways previously impossible. In the late 1990s, by digitizing Star Wars and its sequels, George Lucas was able to add new scenes and creatures, and to improve some of the special effects of the original films. The digitally remastered films were then rereleased.

The 1997 film Titanic used computer-generated images, miniatures, and live-action special effects more extensively than any previous film. Unlike the special effects of previous films, many of Titanic's effects did not make themselves obvious. Instead, they blended into the texture of the film. The result was so effective it was almost impossible to tell that many scenes onboard or in the water were filmed in a studio, and not on location, and that many images, including crowds of people on the ship, were actually computer generated.

V PROJECTING A MOTION PICTURE

Once a motion picture has been shot, processed, edited, enhanced with special effects, mixed, and printed, it is ready to be shown. Films are generally shown in theaters, with a motion-picture projector in the rear of the theater shining the image over the heads of the audience onto a screen in the front of the theater.

When the film runs through the projector, light shines through the film and projects the image forward. The major elements of a projector are a light source with a lens, a film gate through which the film passes from the projection reel, a sprocket that pulls the film down one frame at a time, a shutter that opens and closes as the film passes by, a projection lens, another sprocket through which the film passes to go to the take-up reel, and an optical sound head that reads the sound track.

As a film runs through a projector, each image is shown individually on the screen, and the shutter is timed so that it is open when the image is in front of the light source, and closed when the film is advancing. This happens 24 times per second. The shutter also has a second blade that blocks the light once while each picture is being shown. This produces 48 pulses of light per second instead of 24. (Making the pulse action briefer reduces the flickering of light that the viewers might notice.) Because the human eye does not function fast enough to register each image separately, the images on the screen seem to blend into one, and photographs showing successive positions of a person or object in motion give the illusion of a continuously moving picture.

The sound track is recorded directly on the print film. The projector shines a light through the optical track, which varies in density—thick or thin depending on the strength of the original sound. The projector converts the light that passes through the optical track into an electrical signal, weaker or stronger, depending on the density of the optical track. The electrical signal then travels to the theater's speakers, where it is converted into mechanical energy that produces sound waves that travel to the audience.

Until the early 1950s, motion pictures were generally projected onto a screen with an aspect ratio (the ratio of width to height) of 4 to 3, which is about the ratio of a standard television screen. But then various techniques were developed to project movies at different screen ratios.

Cinerama, the first wide-screen process, was introduced in theaters in 1952. Three 35-millimeter cameras and three projectors were used to record and project a single image onto a large curved screen, with the result that the images blended together to produce an illusion of vastness. Other wide-screen processes soon followed. CinemaScope used a special lens called an anamorphic lens, which compressed a wide image onto standard 35-millimeter film, and a projector that decompressed the image, making it twice as wide as standard screen images. VistaVision achieved a wide-screen effect by using 35-millimeter film transported from right to left horizontally. This allows for a wide-screen image to be photographed without an anamorphic lens onto 35-millimeter film. In the 1960s Panavision became the standard wide-screen process, using an anamorphic lens to achieve an aspect ratio of 2.35 to 1. Currently, most U.S. films have an aspect ratio of 1.85 to 1, while most European films have an aspect ratio of 1.66 to 1. For 70-millimeter films, the aspect ratio is 2.2 to 1.

When a wide-screen film is packaged for viewing in television's aspect ratio of 4 to 3, the sides of the picture are often lopped off. To show the full wide-screen image on home video, the transfer must be letterboxed. In this process, neutral strips of black fill the top and bottom of the TV screen, changing its aspect ratio to represent what was originally used for the theatrical presentation.

VI DISTRIBUTING AND MARKETING A MOTION PICTURE

After films have been produced, they must be distributed to individual movie houses and theater chains. This is accomplished through distributors, who lease motion pictures from the producer or production company. They then pay for the making of prints; arrange screenings so theaters can bid on the rights to show the film; promote and advertise the film; distribute copies of the film to the theaters; arrange for release on cable and broadcast television; coordinate distribution of videotapes, laser discs, and digital video discs to stores; and keep records of the income and expenses for all aspects of film distribution. Distributors bill theaters at the end of engagements, upon receipt of attendance reports.

Sometimes films are not leased, but instead these distribution tasks are subcontracted by the producer to a distributor. The producer then pays for the services by giving the distributor a percentage of the revenue, ranging from 10 to 50 percent of the motion picture's net income. Additionally, the distributor deducts from the producer's share of the net profits the cost for supplying prints of the film and for advertising and promotion.

The Motion Picture Association of America (MPAA) rates films to provide guidance to viewers about what kind of material the movie is likely to contain. There are five ratings. “G” indicates that the film is suitable for all ages. “PG” means that some material may be inappropriate for children. “PG-13” means that some material may be unsuitable for children under age 13. “R” means that anyone under age 17 must be accompanied by a parent or adult guardian. “NC-17” means that no one under age 17 is admitted.

Many films, especially those geared toward children, involve additional marketing beyond the film itself. The film's producers sell the rights—called ancillary rights—to use the film's characters or images to various manufacturers, and various toys, games, and clothing then appear featuring these characters or images. And for many films, separate musical recordings of the songs in the film's sound track are produced and sold in record shops.

Contributed By:

Nicholas Tanis

Jockey on a Galloping Horse

In Jockey on a Galloping Horse English-American photographer Edweard Muybridge captured the actual logistics of a horse in motion for the first time. This and similar series photographs were published in Animal Locomotion in 1887. The works are considered forerunners of motion pictures.

Bridgeman Art Library, London/New York/Stapleton Collection