The utilization of green screens in Computer Generated Imagery (CGI) and Visual Effects (VFX) is a widely adopted industry standard. The reason for this is primarily due to the nature of the green color and its distinctiveness from skin tones and other colors typically present in live-action footage.
The chroma key technique, which is used to remove the green screen background and replace it with computer-generated imagery or other live-action footage, requires a color that is distinct from the subject being filmed. This makes it easier for post-production software to accurately identify and remove the green background.
Green was chosen as the preferred chroma key color because it is distinct from human skin tones, which are predominantly red and yellow in hue, and it is also different from the blue sky and other blue objects commonly present in live-action shots. Green is also brighter than other colors, making it easier to light and easier to key out in post-production.
Additionally, green has become a standard in the industry because it is a color that is easily distinguishable from other colors in the visible light spectrum and it also has a high luminance value, making it easier to light evenly. This results in less color spill, which is when the chroma key color leaks into the foreground subject, causing it to appear translucent or ghostly in the final shot.
Another factor that has contributed to the widespread use of green screens is the availability of green screen fabric and paint, which are readily available and cost-effective. This has made it easier for filmmakers and studios to set up green screens on location or in studio settings.
In conclusion, the utilization of green screens in CGI and VFX is a widely adopted industry standard due to the distinctiveness of the green color from skin tones and other colors typically present in live-action footage, its brightness, and the ease with which it can be evenly lit. The chroma key technique enables filmmakers and VFX artists to create seamless and believable special effects, and the widespread use of green screens has made it easier and more cost-effective to achieve these effects.