Reverse bluescreen is a

visual effect Visual effects (sometimes abbreviated VFX) is the process by which imagery is created or manipulated outside the context of a live-action shot in filmmaking and video production. The integration of live-action footage and other live-action foota ...

s technique pioneered by Jonathan Erland of Apogee Inc.(

John Dykstra John Charles Dykstra, A.S.C. (; born June 3, 1947) is an American special effects artist, pioneer in the development of the use of computers in filmmaking and recipient of three Academy Awards, among many other awards and prizes. He was one of ...

's company) for shooting the flying sequences in the film ''

Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current and ...

''. Its objective is to enable the matting of subjects that confound the conventional process, such as those exhibiting reflective surfaces. It derives its name from the fact that it reverses, or inverts, the basic bluescreen process. Erland received a Scientific and Engineering Award from the Academy of Motion Picture Arts and Sciences for this technique.

Implementation

The patented technique is a variant of the traditional bluescreen

traveling matte Mattes are used in photography and special effects filmmaking to combine two or more image elements into a single, final image. Usually, mattes are used to combine a foreground image (e.g. actors on a set) with a background image (e.g. a scen ...

process for composite photography. The basic bluescreen process calls for filming a subject in front of the solid blue backing, which consists of a translucent blue plastic sheet in front of banks of fluorescent lights. This process poses a problem. A reflective surface on the subject being filmed would result in blue reflections visible to the camera. Since the compositing process entails converting blue in the image into some other background image, such reflections would result in holes in the foreground subject with the background scene showing through. The reverse bluescreen process overcame this problem by coating the foreground subject with a clear

fluorescent paint Luminous paint or luminescent paint is paint that exhibits luminescence. In other words, it gives off Visible spectrum, visible light through fluorescence, phosphorescence, or radioluminescence. There are three types of luminous paints: fluoresc ...

that was invisible under conventional visible light but fluoresced when illuminated by ultraviolet

blacklight A blacklight, also called a UV-A light, Wood's lamp, or ultraviolet light, is a lamp that emits long-wave ( UV-A) ultraviolet light and very little visible light. One type of lamp has a violet filter material, either on the bulb or in a sepa ...

, thus inverting the process. The filmmakers shoot a subject, such as the glossy black jet fighter in the Warner motion picture ''

'', against a neutral (e.g., black) background lit with normal stage lights. Then, they reshoot exactly the same scene (using precise

motion control photography Motion control photography is a technique used in still and motion photography that enables precise control of, and optionally also allows repetition of, camera movements. It can be used to facilitate special effects photography. The process c ...

), but with the normal stage lighting replaced with blacklight. The 360nm UV light causes the fluorescent paint to glow, transforming the plane from black to a glowing object. From this image a male and female traveling matte could be produced that enabled the plane to be composited into any background scene desired.

References

{{Reflist Special effects Film and video technology