Did you know that people have been using what is now know as “green screen” technology as far back as 1918? Only back then, the screen wasn’t green, it was a black screen. Subjects were shown on a large black background and to make the black and white silhouettes, film was copied onto high contrast negatives. The 1933 classic The Invisible Man is the most famous usage of this technique. Green screen technology has come a long way sense then since these early uses.
How does it work?
In the world of video the use of a green screen is commonly referred to as “chroma key.” Simply put, filmmakers mix two different pictures together to create one image. The green screen allows the filmmaker to place an image on top of a different background.
This technique is also known as a “Color Separation Overlay” (CSO). We see this technique in use every time we turn on the local news. Weather reports use a green screen to show weather patterns and graphics that the meteorologist points to. The meteorologist is actually pointing to a green screen, and only knows what he or she is looking at by looking at a monitor.
The Blue screen replaced the black screen in 1925, when C. Dodge Dunning used colored lights to make a background blue and the subjects yellow. In an extremely complicated process, the filmmaker would then split the image using dyes and filters.
In 1940, Larry Butler updated this tedious process by inventing the three-strip color process. This technique was first used to make the iconic King Kong.
In the late 50s, the screen color changed once again this time to yellow. Named the Sodium Vapor Process, the screen itself was actually white, but an orange light when lit turned the screen to yellow.
Walt Disney leveraged this effect to combine live-action with cartoon characters. This was the technique that allowed Dick Van Dyke to dance with penguins in Mary Poppins. He was actually dancing in front of a yellow screen, which allowed the Imagineers at Disney to marry their cartoon drawings with the action on the screen.
It wasn’t until the 1990s that the color of the screen shifted to green. Why green? Cameras—video and photo alike—are more sensitive to this color.
The use of this technology doesn’t have to be purely in the realm of productions like the Matrix or Jurassic World (both of which unsurprisingly used the Chroma Key effect). Even the most amateur of photographer/videographer can reap the benefits of using a green screen with basic editing packages. However to really leverage this technique it requires a professional video production team that is experienced in using this technology.
Oswego Creative has been utilizing green screens for years and has even built its own chroma key green screen studio for our clients’ video needs. Additionally we have developed a number of innovative techniques to produce the best possible image. One of these techniques involves changing the orientation of the camera to improve the “key” of the shot. But don’t just take our word for it, this video shows the difference a single technique can have when utilizing a Chroma key studio.