PAOLO CHERCHI USAI
The history of cinema did not begin with a 'big bang'. No single event -- whether Edison's patented invention of the Kinetoscope in 1891 or the Lumière brothers' first projection of films to a paying audience in 1895 -- can be held to separate a nebulous pre-cinema from cinema proper. Rather there is a continuum which begins with early experiments and devices aimed at presenting images in sequence (from Étienne Gaspard Robertson's Phantasmagoria of 1798 to Émile Reynaud's Pantomimes lumineuses of 1892) and includes not only the emergence in the 1890s of an apparatus recognizable as cinema but also the forerunners of electronic image-making. The first experiments in transmitting images by a television-type device are in fact as old as the cinema: Adriano de Paiva published his first studies on the subject in 1880, and Georges Rignoux seems to have achieved an actual transmission in 1909. Meanwhile certain 'pre-cinema' techniques continued to be used in conjunction with cinema proper during the years around 1900-5 when the cinema was establishing itself as a new mass medium of entertainment and instruction, and lantern slides with movement effects continued for a long time to be shown in close conjunction with film screenings.
Magic lantern, film, and television, therefore, do not constitute three separate universes (and fields of study), but belong together as part of a single process of evolution. It is none the less possible to distinguish them, not only technologically and in terms of the way they were diffused, but also chronologically. The magic lantern show gradually gives way to the film show at the beginning of the twentieth century, while television emerges fully only in the second half of the century. In this succession, what distinguishes cinema is on the one hand its technological base -- photographic images projected in quick succession giving the illusion of continuity -- and on the other hand its use prevailingly as large-scale public entertainment.
Films produce their illusion of continuous movement by passing a series of discrete images in quick succession in front of a light source enabling the images to be projected on a screen. Each image is held briefly in front of the light and then rapidly replaced with the next one. If the procedure is rapid and smooth enough, and the images similar enough to each other, discontinuous images are then perceived as continuous and an illusion of movement is created. The perceptual process involved was known about in the nineteenth century, and given the name persistence of vision, since the explanation was thought to lie in the persistence of the image on the retina of the eye for long enough to make perception of each image merge into the perception of the next one. This explanation is no longer regarded as adequate, and modern psychology prefers to see the question in terms of brain functions rather than of the eye alone. But the original hypothesis was sufficiently fertile to lead to a number of experiments in the 1880s and 1890s aimed at reproducing the so-called persistence of vision effect with sequential photographs.
The purposes of these experiments were various. They were both scientific and commercial, aimed at analysing movement and at reproducing it. In terms of the emergence of cinema the most important were those which set out to reproduce movement naturally, by taking pictures at a certain speed (a minimum of ten or twelve per second and generally higher) and showing them at the same speed. In fact throughout the silent period the correspondence between camera speed and projection was rarely perfect. A projection norm of around 16 pictures ('frames') per second seems to have been the most common well into the 1920s, but practices differed considerably and it was always possible for camera speeds to be made deliberately slower or faster to produce effects of speeded-up or slowed-down motion when the film was projected. It was only with the coming of synchronized sound-tracks, which had to be played at a constant speed, that a norm of 24 frames per second (f.p.s.) became standard for both camera and projector.
First of all, however, a mechanism had to be created which would enable the pictures to be exposed in the camera in quick succession and projected the same way. A roll of photographic film had to be placed in the camera and alternately held very still while the picture was exposed and moved down very fast to get on to the next