Building the Chromakey Studio
To capture the digital footage of the performers to use in the installation it was necessary to film them in front of a green screen. This is needed so that during the editing process, the green background can be erased, or keyed out. Final footage is of dancers against a transparent background. This allows the dancers to appear in the head mounted display and look to the audience member as though they are inhabiting the same physical space at the installation.
While this video effect has been around for many years and is commonly used by the TV weather man, it takes a considerable amount of effort and know-how to create. If the green screen footage is shot improperly, post-production editing will be adversely affected. The optimal conditions for chromakey filming include the largest area of green possible, such that the performer can be placed as far from the green background as possible. This technique allows the performer to be lit separately from the background, and allows the camera to perceive the background as slightly out of focus. These measures all contribute to better results in post-production editing. Since we were filming dancers, it was necessary to have not only a green backdrop but also a green floor so that we would be able to film their feet and legs.
To get the highest quality footage we were able to obtain within our means, we built a chromakey or green screen studio in a theater space generously donated by Columbia University. This space was a great resource for us since it had a grid we could use to hang both lights and our green backdrop. Unfortunately, it was not permissible to paint the floor in this space. This meant we needed to build a stage that we could paint in chromakey green. The stage also needed to be safe and rugged enough to endure several days of modern dance. Additionally, it was not possible to find a space in New York City where we could build and paint the stage. This is no surprise since space is a scarce resource in many large cities. We were lucky to have a garage space available to us in a nearby town in Connecticut. Brendan Padgett and I designed the stage and went to Connecticut to construct it. We created a modular design that would allow us to fit the pieces of the stage into a rented cargo truck for transport back to the theater space in New York.
I purchased the appropriately pre-cut pieces wood from a lumber supplier in Connecticut. Padgett and I built and painted the stage components by hand in the garage space in Connecticut and completed the final assembly together at the theater space in New York City. I also rented a package of lights from a New York City film lighting house since theater lights have only half the amount of wattage necessary. It is important to remember that opposed to theater lighting, film lighting must be created for the camera, not the human eye. Therefore, different equipment and materials are required. Joseph Pauls, the lighting designer and cinematographer, created the lighting design we used for the three-and-a-half day shoot. Due to resource constraints, while we were able to conduct additional audio recording at later dates, no further video shoots could be conducted. This added an additional constraint to the video shoot.
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