READING 3.3

JUMP CUT

FROM BLACK SACKS TO GREENSCREENING

Melies

                 Georges Méliès

Let’s begin with a couple of observations about certain feats of special-effects legerdemain that were obviously among Georges Méliès’ favorites—namely:

  1. The frequency with which there appears in Méliès’ films, usually in the background center of the set, some sort of black proscenium that typically represents an architectural feature; the large stone-framed archway in L’Homme à la tête de caoutchouc is a very good example.
  2. The fact that in La Photographie électrique à la distance, the inventor played by Méliès makes a point of demonstrating the portability of his black projection screen; a careful look reveals a subsequent stop-action cut each time the prop screen is moved from one point to another.

The black background is the crucial element in Méliès’ favorite—and arguably most important—cinematic trick. Into the theatrical scene enacted by living actors among physical properties Méliès is able to project separately filmed images featuring live-action performers, sometimes life-size, often smaller than life-size, sometimes (as in L’Homme à la tête and La Photographie électrique) larger than life-size. We needn’t watch very many of Méliès’ films before we realize that the black-background region of the screen always demarcates an area of the theatrical set that’s been reserved for the projection of these inserted images.

How to Make “Artificially Arranged Scenes” or “Moving Tableaux”

The technique that Méliès employs in these demonstrations of cinematic ingenuity involves composite images and has various names—generally, background work or, more specifically, black-background technique. Basically, it works as follows:

See the moving picture

Dislocation

              Georges Méliès, Dislocation

              mystèrieuse, Star-Film, 1901

The black background, especially when combined with other optical tricks, offers the filmmaker a number of additional opportunities to concoct what Méliès called his “artifically arranged scenes” or “moving tableaux.” Consider, for example, Dislocation mystèrieuse (Dislocation Extraordinary, 1901—Figure R3.7), in which the body parts of a clown cavort independently of his dancing torso. How does the black-background technique work in this case?

The Black-Backing Traveling-Matte Process

Fulton

                 John P. Fulton

Now let’s jump forward in time to take a look at The Invisible Man, which was directed by James Whale for Universal Studios in 1933. The technique that allows us to watch the Invisible Man move about without seeing the unclothed parts of his body (Figure R3.8) is a more sophisticated version of the black-background technique worked out by special-effects expert John P. Fulton (1902-1965). By the 1930s, it was called the black-backing traveling-matte process, which, in The Invisible Man, was worked out as follows:[1]

Greenscreen Imaging

StarWars

          Star Wars: Bluescreen Imaging

In the computer age, the black-background technique and the black-backing traveling-matte process have evolved into a more sophisticated special-effects technique called the bluescreen process or bluescreen imaging.[2] This procedure, which has also become quite important in the creation of television commercials and video games, calls for photographing a live-action subject (called the foreground) in front of a bright, evenly lit, pure blue backing. The imagery that ultimately replaces the blue backing is called the background plate. The composite consists of the multiple images—the foreground image plus the background plate—that are combined to create the final visual product. As you can see from Figure R3.10 [3], other colors—notably, blue—can be used for the screen, but green is preferred because it’s the furthest away from human flesh tones. If other colors predominate in either the foreground image or the backing, another backing color may be more effective.[4]

Rotoscoping

StarWars

                Star Wars: Rotoscoping

A related process called rotoscoping dates from an earlier era in special-effects technology, which used animated special effects to enhance live-action sequences. A form of this process, for example, was used to create the glowing lightsabers in George Lucas’ Star Wars films (1977-2002), which also made extensive use of bluescreen imaging:

Digital Rotoscoping  

As the name suggests, digital rotoscoping delegates such tasks to the computer. This is the technique that makes actor Gary Sinise a strikingly believable amputee in the 1994 American movie Forrest Gump (Robert Zemeckis—see Figure R3.12). As Sinise played his part for live-action footage, his calves and feet were covered with specially made blue socks (reminiscent of the black-sack covering that Méliès had used nine decades earlier). The areas masked by the blue socks were then used in much the same way as the mock swords in Star Wars: they guided digital animators in the creation of the imagery that appeared in place of Sinise’s amputated limbs. In this case, of course, it was not merely a matter of replacing one form of an object (a metal-rod sword) with the similar form of another object (a hand-painted lightsabre): Sinise’s limbs had to be “erased” and the background plate filled in with the details that could be seen because the limbs weren’t blocking them from view. In effect, the blue socks functioned as a blue screen on which digitized images, adjusted pixel by pixel for color, shadow, and texture, could then be inserted.

The Chroma-Key Process  

Sometimes called bluescreening or greenscreening, chroma-keying or the chroma-key process uses digital editing tools to perform such tasks as selecting the optimal background color and painting over it with the desired background. Using special Ultimatte equipment, digital compositors can create imagery that includes smoke, shadows, and transparent objects. Both chroma-keying and Ultimatte processing are used only for television and video production and postproduction.[6]


[1] See John Brosnan, Movie Magic: The Story of Special Effects in the Cinema (1974; rpt. New York: New American Library, 1976), pp. 71-73. Fulton himself explained the process in some detail in the September 1934 issue of American Cinematographer: Joe Winters, “The Invisible Films Return” (I), Horror Wood Website, September 2002, at www.horror-wood.com (accessed November 2, 2004). See also “The Wild and Wonderful World of John P.Fulton,” Matte Shot—A Tribute to Golden Era Special Fx, August 28, 2010, at http://nzpetesmatteshot.blogspot.com (accessed June 9, 2016); “The Art of Invisibility according to Fulton and Horsley,” Matte Shot—A Tribute to Golden Era Special Fx, November 2, 2010, at http://nzpetesmatteshot.blogspot.com (accessed June 9, 2016). For more on the use of optical effects in American movies of the 1930s, see Tino Balio, Grand Design: Hollywood as a Modern Business Enterprise 1930-1939 (1993; rpt. Berkeley and Los Angeles: Univ. of California Press, 1995), pp. 133-35.

[2] See Tom Russo, “Movies 2.0: Digital Effects Magic Explained,” Popular Mechanics, September 30, 2009, at www.popularmechanics.com (accessed June 9, 2016); Mark Fischetti, “Leap of Faith: Blue Screens Explained,” Scientific American, January 17, 2008, at www.scientificamerican.com (accessed June 9, 2016); Steve Bradford, The Blue/Green Screen Page (1995-2008), at www.seanet.com (accessed June 9, 2016). For a clear step-by-step illustrated description of the bluescreen process, go to Marshall Brain, “How Blue Screens Work,” How Stuff Works (1998-2011), at www.howstuffworks.com (accessed June 9, 2016).

[3] For Figure R3.10: Gerri Miller, “Inside ‘300,’” How Stuff Works (1998-2011), at http://entertainment.howstuffworks.com (accessed June 9, 2016); Tom Russo, “Movies 2.0: Digital Effects Magic Explained.” Also consulted: Rob M. Worley, “300 Matches Miller Style” (July 27, 2006), Mania (2012), at www.mania.com (accessed February 27, 2014).

[4] See Lightcraft Technology (2005-2014), “Keying Interface—Blue vs. Green Screen” (December 3, 2014), at www.lightcrafttech.com (accessed June 9, 2016).

[5] For Figure R3.11: “How Does a Star Wars Lightsaber Work?” HowStuff Works (1998-2011), at www.howstuffworks.com (accessed June 9, 2016); Michael Kaminsky, “Saving Star Wars: The Special Edition Restoration Process and Its Changing Physicality,” The Secret History of Star Wars (2007-2009), at http://fd.noneinc.com (accessed June 9, 2016). To learn how to make your own lightsaber using Apple Motion, go to Conor O’Sullivan, “Creating Lightsabers in Motion” (CPO Studios, 2005), at http://cpostudios.com (accessed June 9, 2016). Also consulted: “Lighting a Saber,” starwars.com (Lucasfilm, 2004), at www.starwars.com (accessed November 2, 2004).

[6] See esp. Bradford, The Blue/Green Screen Page. See also Ranjan Parekh, Principles of Multimedia (New Delhi: Tata McGraw-Hill, 2006), p. 351.

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