Persistence of Vision and its relation to Animation
Persistence of Vision is the fundamental theory of motion picture. The understanding of this theory is the fundamental to understanding animation. This is a common theory for animation and for live action film.
The theory states that the human eye always retains images for a fraction of a second. This means that everything we see is a subtle blend of what is happening now and what happened a fraction of a second ago.
This phenomenon is caused by a visual form of memory known as iconic memory. Few psychologists have rejected the relevance of this theory to film viewership; persistence of vision is still the accepted term for the theory of motion picture and animation. In the early days of film innovation, it was scientifically determined that a frame rate of less than 16 frames per second also known as fps caused the mind to see flicker or flashing images. In case of a flip book animation it was ok to have the slow animation going below 16 fps. But in case of a film projector, playing a film below 16 frames per second was disturbing for the human eyes.
All modern theatrical film runs at 24 frames per second. This is true for both film camera and for digital technologies.
In hand drawn traditional animation, the drawings of the animation characters are shot “on twos”; that is two photos for each drawing. This means, there will be 12 drawings and 24 photos for one second of animation. When the character need to perform a fast action, it is filmed in “on ones” basis. So that there will be a fast motion for the character. These two techniques combined together fool the human eye to create the illusion of movement.
As you all know that the illusion of movement created by showing a series of images in a brief period of time is Animation.
Persistence of Vision is the fundamental theory of Motion Picture and Animation. This blog gives a clear definition of the theory and establishes the connection between the theory and animation.