Stop motion is a general term for an animation technique that makes static objects appear to move. This technique dates back to the late 1800s, and involves shooting scenes to tell a story frame by frame, changing only a small movement within each shot.
The first stop motion film created was The Humpty Dumpty Circus by Albert E. Smith and J. Stuart Blackton. Unfortunately, the film has been lost and only exists now as still images. Smith used his daughter's ball jointed circus dolls to create the film, which allowed for ease in posing the dolls for the creation of varied frames.
Stop motion was used in early filmmaking as a cost effective way to handle special effects. Famous stop motion animator Willis O’Brien used stop motion to animate special effects in King Kong in 1933, which was wildly successful. The film's success was dependent on O'Brien creating realistic creatures, not only the giant gorilla Kong, but also the dinosaurs with which he battled. O'Brien was obsessive about details, basing his dinosaur models on the most exact paleontological studies and, most importantly, creating a Kong that was not just a model, but a character. Unlike previous projects where the creatures had been simply foes, Kong was a complex being who the audience had to sympathize with and who had to display emotion. O'Brien studied facial expressions and body language to fully bring Kong to life, and then the stop motion sequences filmed using miniatures were rear-projected to integrate the footage with live action sequences.
Special effects artists used stop motion animation to bring the At-At Walkers to life in the original Star Wars movies. The team of artists originally thought about using actual robot versions of the walkers, but that idea “proved to be too costly and complicated.”
"Models were manipulated a frame at a time, animated in front of painted backgrounds instead of blue screen, with baking soda was used in place of snow. It was shot at 24 frames per second, resulting in about 5 seconds of footage per day of work. For explosions, high speed photography was used, and cutouts were used for background walkers."
Click here to watch a featurette on how stop motion animation was used in Star Wars: Episode V—The Empire Strikes Back.
Today stop motion animation is still used, in films such as The Corpse Bride, Coraline, and Paranorman.
The Persistence of Vision
Animation creates the impression of movement through an optical illusion referred to as the “Persistence of Vision.” The eye retains an image for a split second after it has actually been shown. Animation works by presenting slightly different images in quick succession, with the persistence of vision filling in the gap between each image and allowing for the illusion of motion.
Today’s motion pictures flash images on the screen at 24 frames per second (or 48, in that each frame is flashed twice) for a flicker-free picture. You may remember making flipbooks as a child. They worked on this same principle: the more images per second, the smoother the picture.
In the late 1800s, details of how objects move were widely unknown. The human eye, unaided, cannot resolve the details of fast motion. English photographer Eadweard Muybridge changed all of this with his pioneering work in photographic studies of motion. His series of images of a horse's gait helped solve the mystery of motion.
Muybridge’s experiments in photographing motion began in 1872, when the railroad magnate Leland Stanford hired him to prove that during a particular moment in a trotting horse’s gait, all four legs are off the ground simultaneously. His first efforts were unsuccessful because his camera lacked a fast shutter.
In 1877 Muybridge resumed his experiments in motion photography, using a multitude of cameras and a special shutter he developed that gave an exposure of 2/1000 of a second. This arrangement gave satisfactory results and proved Stanford's claim.