Optical and Special Effects - Text 1
For the first three decades of film history, exhibitors almost always screened release prints struck directly from camera negatives. It is only with the introduction of Eastman Duplicating Film in 1926 that the production of interpositives and internegatives became a practical reality.[1] The use of intermediate elements made it possible to greatly reduce the number of operations involving the precious camera negatives, and consequently helped protect them from wear and tear. It also greatly simplified the printing process: once the interpositive had been graded, the printing of the hundreds of copies typically needed for studio releases did not require corrections to be done on individual shots during the printing process, as had been the case when release prints were struck from ungraded camera negatives.
Yet another significant advantage of using duplicating stock was that it enabled filmmakers to produce optical and special effects during post-production and not during principal photography. Filmmakers, like photographers a few decades before them, had been quick to realize that images captured on light-sensitive emulsion can be manipulated, masked, divided or multiplied. While some of these operations sought to create spectacular illusions, others were used to enrich the grammar of narrative cinema. Masks and iris shots, for instance, could be used to direct the attention of viewers, while fades could signal a temporal ellipsis.
Moving picture cameras designed for studio work soon incorporated multiple features that facilitated the production of these optical and special effects. The Pathé Professionnelle, which in many respects was an evolution of the Cinématographe Lumière, made it possible for the operator to shoot trick shots by using a second crank recording a single frame per revolution. This novel feature made possible the creation of films and sequences making use of stop-motion animation and pixilation.