• CINEMA SYSTEMS • Projection Series-XXIV
3D Film Projection 3D Film 3D Film Projection Projection Since the evolution of celluloid entertainment, there had been some truly fascinating formats that gave new expression to cinema. The three-dimensional format - popularly called 3D has been one. In today's digital age, the format is gaining more prominence than ever. For, the sheer variety of imagery takes the audiences into a whole new world of wonderment. As part of the continuing series on sound and projection, Theatre World, this time in the fourth part of Unit-VI, presents 3D film projection. At a time when film is fast disappearing, it may be relevant to know what exactly was, and, is, the 3D format. Like painters and photographers, filmmakers and cameramen have striven hard for long to give their audiences the perception of depth, within the limitations of a two-dimensional image. In the cinema, attempts to reproduce genuine 3D images had, however, not met with much commercial success, and therefore tended to be short-lived novelties. Any 3D projection system has to take account of the fact that the audiences perceive depth because they have two eyes, set about 2½ inches apart, which capture the same scene from two slightly different angles. We call this principle stereoscopy. The first application of stereoscopy to the photographic capture of images required two camera lenses and two films to capture the separate images for the left and right eye. Similarly, during projection, two separate images had to be projected simultaneously, but with a slight off-set, so that no matter where the viewer sat the left eye could only see the left image and the right eye the right image. Black-and-white stereoscopic films were first produced quite cheaply, using the anaglyph system where the two separate images are printed onto a single strip of film in two complementary colours. The film was then viewed using complimentary-colour filters so that the left eye image on the film was formed in blue green (cyan), and the right in red. The viewer viewed the left eye's bluegreen image through the red filter and the right eye's image through the blue-green filter. A superior Polaroid system was first used in 1939 at the New York World Fair. In this system, light polarizing filters were used to block out the unwanted image from each eye. The left eye's image was projected and viewed through a vertical polarizing filter and the right eye's image through a horizontal one. The screen for this projection system, however, had to be the same regular silver screen so that the light from the projector was reflected without changing its polarization. That the early system required two separate 35mm films running on
two interlocked projectors it was quite complex, and difficult to operate to perfection.
The principle of polarized 3D projection
The first public 3D screenings were in the 1920s using the anaglyph system. However, it was not until 1951, when the Polaroid system was used at the Festival of Britain for as many as 1220 sellout performances of a short film, that Hollywood started to take the idea seriously. Over the following three years the major studios made about 100 feature movies in 3D before the boom was over. Then they turned to the new 2D widescreen system - the Cinemascope - which did not require the audiences to wear glasses.
3D polarizing glasses
April-June 2009
Theatre World
TW-33