Frame-by-frame animation is more commonly known as stop-motion animation. It is achieved by manipulating a physical object and making it appear to move on its own by shooting one frame, manipulating the object, then shooting another frame, and so on. A famous example of frame-by-frame animation is the 1933 film, King Kong. The giant ape is shot in this animation style, making it seem as though he is moving on his own. Other forms of animation fall under the frame-by-frame category as well, such as cel animation and object animation.
Clay puppets are commonly used when filming frame-by-frame animation because their movements can be easily manipulated between frames with minimal risk of damage to the puppet itself. It is a relatively newer form of animation, but it took hold as a popular form of stop-motion, especially when geared toward children's programming. This type of frame-by-frame animation is often aptly called claymation.
Other forms of frame-by-frame animation rely on manipulation of solid objects rather than malleable ones. A stop-motion film can be shot, for example, of a model car driving up the street by taking a shot of the car in one frame, moving it up the road a bit, then taking another shot. this principle mirrors that of claymation, but the object itself is not malleable and therefore cannot imitate human or animal expressions. This is called object animation and is one of the oldest animation techniques.
Perhaps the oldest form of animation is cel animation, which is a frame-by-frame animation technique in which scenes of a film or show are drawn by hand on clear cels. Each hand-drawn cel varies slightly from the one before it to convey motion when the cels are photographed by a special camera. When these images are shot onto a reel, the final product shows each cel in rapid succession, thereby mimicking movement. It is important in this case to make sure each cel lines up carefully with the others when shooting, or else the final product will appear jittery or jumpy.
Since the advent of Computer Generated Imagery, or CGI, stop-motion animation has been largely rendered obsolete. CGI is less time consuming and labor intensive, and motion can be manipulated in far more ways than with simple stop-motion animation. However, stop-motion animation is still in use, as its final product retains a characteristic look that is popular among critics and fans.