|March 18, 2002|
The Early Days
Moviegoers marveled the first time Superman soared across the sky in his quest to defeat evil. But what was state-of-the-art in 1978 is no longer as convincing. Today's moviegoers have come to expect amazing effects that put them right in the middle of the action: a fishing boat battling ninety-foot waves in The Perfect Storm; giant, life-like dinosaurs devouring their prey in Jurassic Park; a terrifying plane crash in Cast Away. Special effects have come a long way since they first appeared.
Have you ever seen the 1933 movie King Kong? It is one of the most memorable examples of early experiments with special effects. King Kong himself was an animated model, brought to life on screen using stop-motion filming. It is a very labor-intensive method: models have to be moved a fraction of an inch, their facial expressions changed, and then shot, with 24 different shots being taken for just one second of film.
King Kong's costar in the movie was the actress Fay Wray. If Kong was an animated model, how did the early filmmakers make it look as though he was interacting with an actress? The answer lies in a technique known as "optical printing." The producers filmed Kong and Fay Wray separately. They then projected the two films together and used another camera to record the information on a third reel of film. The result: on film, it looks as though Fay Wray is right there with Kong. The separate elements animation, scenery, and human characters were merged to appear as though they all existed together during filming. The scene appears real. This blending of shots is now known as compositing. It's still done today, but using different methods.
These days, instead of a jerky King Kong, you'll see humans walking with authentic-looking dinosaurs in a lush forest. The old technique of optical printing has been replaced with digital compositing.
One important tool in digital compositing is the "blue screen." Movie stars perform a scene in a studio, in front of a blue screen. Later, computer programs are used to replace the blue background with a real background, such as an ocean scene. So, even though the actor was filmed in a studio, it will look like he was filmed out at sea.
The blue screen was used several times in the movie Forrest Gump. In one of the most memorable scenes, actor Tom Hanks appears to shake hands with President John F. Kennedy who in reality passed away over 35 years before the movie was made. The movie producers filmed Hanks in front of a blue screen, pretending he was interacting with the President. They then used computer technology to isolate Hanks and insert him into an old film clip featuring President Kennedy.
The Nickelodeon movie Clockstoppers, which will be released on March 29th, uses the technique known as "time-slicing." It was important for the Clockstoppers plot that objects appear to be frozen in time. In the movie, the camera seems to rotate around objects, giving you a three-dimensional view of them as they stand still. In fact, a ring of cameras is positioned around the object, and the cameras all take a still image at the same time. When the images are played together, it looks as though there is one camera moving around the object, caught in one moment of time.
Computer power has opened up new doors for filmmakers. The dramatic
of James Cameron's Titanic (1999) would not have been possible without "CGI," or
Computer-Generated Imaging. Computer graphics were used to fill in details and build scenes
that could not be filmed, such as the ship sinking in the distance. In Gladiator (2001),
version of the Colosseum was used as the set; the vivid details you see
in the movie were filled in using computer graphics.
Computer animation has taken on a life of its own, too. Sometimes, animated characters interact with real scenes and humans on screen: in The Lord of the Rings, many of the creatures Frodo and Samwise encountered such as the Cave Troll in the Mines of Moria were computer-animated. Flubber starred computer-animated goo alongside actor Robin Williams. In another Williams movie, Jumanji, the jungle animals that trampled through town destroying everything in their path weren't real.
The biggest news in computer animation is this year's new Oscar category of "Animated Feature Film." The three contenders are Monsters Inc., Shrek, and Jimmy Neutron: Boy Genius. The much-admired detail of these movies (think of Sulley's furry coat in Monsters Inc.) would have been painstaking to create in old hand-drawn animations, but today's powerful computers make it possible to make animated characters seem very real.
The Price of Effects
by Zora Warren of the Harvard Graduate School of Education's "Technology in Education" program