The movie industry switched from blue screen to green screen for special effects because green screens provide a higher level of precision and detail in post-production editing. This precision is due to the way cameras and software interact with the color green.
Green screens allow for more accurate extraction of foreground subjects, which is crucial for creating seamless special effects. This is because the color green is not present in human skin tones, making it easier for software to distinguish between foreground subjects and the background. Blue screens, on the other hand, can sometimes result in a "blue spill" effect, where the blue from the screen reflects onto the foreground subject and makes editing more difficult.
Additionally, green screens provide better color contrast for outdoor and nature-based scenes, as blue screens can sometimes blend in with the sky or water. Green screens are also easier to light evenly, as they require less light to appear evenly lit on camera compared to blue screens.
The decision to switch from blue to green screens was not immediate, and there were several factors that contributed to the transition. One major factor was the increasing use of digital technology in the film industry, which made it easier to digitally edit footage shot against green screens. Additionally, advancements in green screen technology made it more affordable and accessible for smaller productions to use.
Overall, the decision to switch from blue screen to green screen was based on the benefits of increased precision and flexibility in post-production editing, as well as the practical advantages in lighting and color contrast. These factors made green screens the preferred choice for special effects in the movie industry. Sources for this information include The Hollywood Reporter and The New York Times.