Behind the Screen Study Guide The Illusion of Motion The moving image is actually a series of still images, A succession of still images can produce the appearance of motion. When each image is a bit different from the one before, we seem to see only one image of something moving. These still images can be: Drawings Nineteenth century moving image toys like Zoetropes and flipbooks made use of drawings, as do animated films. Photographs Motion pictures are really a series of photographs. Scanned Images Television uses a series of stills to create motion, but they are not photographs. What we see on the screen are electrically simulated lines of light that form an image. presented to the eye in rapid succession, A slowly blinking light can be seen to go on and off. Blinking at a more rapid rate, it will seem to flicker. However, if the light goes on and off even faster, the flicker will disappear. The light appears to be on continuously, because we retain the image of what we see for a moment after we see it. This is often referred to as visual persistence. Film Frame Rate Film is shown at a rate of 24 pictures per second. A slower rate will produce a flicker, which is why early hand-cranked projectors, which were often run at a slower rate, earned movies the name "flicks." Television Frame Rate The American television frame rate is thirty frames per second. Each "frame" is actually a 262-line image lasting one sixtieth of a second followed by a second 262-line image lasting another one sixtieth of a second. Because of visual persistence, we see a 525-line picture. and separated by a brief interval of darkness. We retain an image for a fraction of a second after we first see it. In order for us to see a moving image instead of a blur, each image in the series needs to be separated. The interval of darkness gives us enough time to take in the image, and as soon as we are ready to let go of this image, the next image comes into place. Nineteenth-Century Moving Image Devices Images can be attached to a wheel that is spun, as in the Zoetrope. Looking at the slotted cylinder-which forms a shutter that allows for an interval of darkness between each image-the eye sees the drawings flashed in sequence. Or the images can be put together as a flipbook. Flipping through the pages animates the drawing, and the interval between the pages acts as the shutter. Film Projectors A series of photographs on a single strip of film can be shown by a projector. The projector moves the film in a stop-and-go motion that allows one still picture to advance at a time, and a shutter provides an interval of darkness between each frame. Television Sets The scanned images are electronically generated, one after another, on the television screen. The interval of darkness is provided by the rapid alternation of the 262- line image. Animation Animation involves the filming of a series of still images frame by frame. When projected at film speed, what the images portray appears to be in motion. The art of animation existed in crude form long before the arrival of motion pictures, for it is the animation principle that underlies the simple technology of nineteenth-century moving image toys like the Zoetrope. Animations were among the earliest motion pictures. By the 1920-s the Fleischer Brothers in New York and Walt Disney Studios in Hollywood had begun to specialize in the production of animated cartoons. The technique they used was called cel animation. "Cel" is short for the celluloid sheets on which these cartoons were made. Computer technology has given rise to a new form of digital animation that can supplement, or replace, traditional animation techniques. TOY STORY (1995) was the first theatrical motion picture generated entirely by computer. Each individual frame required about 300 megabytes of computer storage, more than the storage capacity of 200 floppy disks. The complete film contains approximately 110,000 frames. index | next