Film is an art with a long standing history. It could be defined as a record of an image upon a sensitive material called cellulose through the action of light (Kogah, 1999). It is a medium of mass communication whose main component of production technology are the camera and editing equipment; the film projector being the main reception technology, (Anunike, 2005). To Uwakwe (2010), film comprises of individual frames which when shown in rapid successions gives the viewer the illusion of motion. According to Bittner (1989), the motion picture is a medium of mass communication which has touched every segment of the society, has touched and dealt with every subject and has reached every audience. And because some film makers combine entertainment with instruction, films make learning process more pleasurable. It could therefore be described as an art as well as a business which makes those who create it take pride in their creations. It is a significant medium of communication of ideas designed to entertain as well as inform its audiences (Biagi, 2002). Films are illusion of motion which could be used to teach people about history, science, arts, human behavior, culture, health and many other aspects of life.
All these definitions and descriptions of film or motion picture clearly show that films fulfill many roles in the society which are (a) they educate, (b) they enlighten (c) they inspire (d) they play back history (e) provide opportunity for social interactions (f) and they provide platforms for academic works.
What is Persistence of vision
Film comprises of individual frames which when shown in rapid successions gives the viewer the illusion of motion. The flickering between films is not visible due to an effect known as persistence of vision. Persistence of vision is the very foundation on which motion picture is based. It is a theory propounded in 1824 by Peter Mark Roget, a scientist and a French national. This theory states that when
still photographic frames are projected at the speed of 2 frames per second, there is bound to be an illusion of motion. This is likened to a mirage on a tarred road on a sunny afternoon. Just as there is no real water on the road, there is also no motion on the screen. This happens because at a particular speed, say the normal speed of 24 frames per second, the eye can no longer continue to notice the difference between successive frames resulting in the illusion of motion.
In this theory, Peter Roget explains that the human eye retains an object or image for some fractions of a second when the object has been removed and kept out of the viewer’s eye. This persistence of vision creates an illusion of motion. It is so described because what the eye sees is not real moving images but rather an illusion of motion resulting from rapid succession of countless still photographs. This phenomenon can be further explained thus because the viewer is looking at the pictures persistently with full concentration, the subconscious gives the illusion of movement that never be. In other words, due to intermittent recording coupled with a given speed of projection, the persistence of vision forces the subconscious mind to make wrong interpretation that turns out to be an illusion of movement.
This phenomenon, ie persistence of vision is quite different from the phi phenomenon. Although, these two, (phi phenomenon and persistence of vision) are the two quirks of the human perceptual system which make motion pictures and television possible, (Dominick, 2002). Phi phenomenon as described by Dominick (2002) refers to what happens when a person sees one light source go out while another one close to the original is illuminated. To our eyes, it looks like the light moves from one place to another.
Source:NATIONAL OPEN UNIVERSITY OF NIGERIA