History of the green screen

Title speaks for itself, just a paper I had to write for my Tv Production class.

History of the green screen

    It first started out as the blue screen and traveling matte, it was developed in the 1930s. It was used to create special effects for The Thief of Bagdad. Larry Butler takes credit for the development of the blue screen; he won the Academy Award for special effects in The Thief of Bagdad. The background footage is shot first. And the actor or model is filmed carrying out their actions against the blue screen. Then you would place the foreground shot over the background shot. The actor or model must be separated from the background and be placed into a special made hole in the background footage. The background image is then re-photographed through male matte and then through female matte.

  The principal subject is filmed or photographed against a background consisting of a single color or a relatively narrow range of colors, usually blue or green because these colors are considered to be the furthest away from skin tone. The portions of the video which match the preselected color are replaced by the alternate background video. This process is commonly known as keying, keying out or simply a key.

  One drawback to the traveling matte is that cameras shooting the images to be composted cannot be easily synchronized. For Star Trek: The Next Generation, an ultraviolet light matting process was proposed by Don Lee of CIS and developed by Gary Hutzel. A fluorescent orange backdrop made it easier to generate a holdout matte. This allowed the effects team to produce effects in a quarter of time needed for different methods. Some films use Chroma key to add backgrounds that are constructed using computer generated imagery.

  Computer development also made it easier to incorporate motion into composite shots, even when using handheld cameras. Reference-points can now be placed onto the colored background In post-production, a computer can use the references to adjust the position of the background, making it match the movement of the foreground perfectly. Modern advances in software and computational power have even eliminated the need to use grids or tracking marks �" the software analyzes the relative motion of colored pixels against other colored pixels and calculates the 'motion' to create a camera-motion algorithm which can be used in composite software to match the motion of composite elements to a moving background plate.

  Today, green screen technology isn’t just confined to massive budget studios. It’s also used in photography. From the initial blue screen, green was used later on because filmmakers discovered that a green background doesn’t need tedious lighting. Cameras are most attuned to this color, so the outcome of films shot on green screens are more easy to work with and change. While acknowledging that, Chroma key technology is now known to photographers and filmmakers all over.