Chroma Key
Definition
Chroma Key is a visual effects and post-production technique for compositing (layering) two images or video streams together based on color hues. A subject is filmed in front of a uniformly colored background (most commonly green or blue), and the post-production software removes all pixels of that specific color, making them transparent and allowing a different background to be placed behind the subject. Green screen is preferred in most modern productions because digital camera sensors are most sensitive to green, making it easier to achieve a clean key.
Contextual Usage
The VFX supervisor briefs the production team before a green screen shoot: "We need to make sure the green screen is evenly lit with no hot spots or shadows. Any unevenness in the lighting will create problems during the Chroma Key process in post, and we'll end up with a dirty key."
About this section
Production — or "principal photography" — is the phase in which the film or video is actually shot. It is the most visible and, typically, the most expensive phase of the entire process. Every day on ...
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