What is Chroma key(traditional) and how does it work
Chroma key is a widely-used technique that allows foreground objects to appear in a video scene even though they were not present – and often could not have been present – when the scene was shot.
Chroma key effects are often called “blue-screen” or “green-screen” effects because the foreground action is shot in front of a uniform blue or green background. The background is then electronically removed, leaving only the foreground action to be superimposed on the actual background of the final scene, which has been separately prepared.
Blue and green are the generally-preferred colors for chroma key use because their removal from an image will not affect human skin tones, but in principle any hue can be used with Studio’s chroma key tool.
LED Chroma key system
Now the brand new LEDchroma Key technology is graduallytaking place rather using the traditional old “blue-screen” or “green-screen”chroma key system – no blue, no green screen and no heavy lights and reflectors, simply grey screen and blue-green LED lights.
The advanced LED chroma Key system uses a grey cloth that is made up of thousands of tiny glass beads that are almost invisible to the naked eye. Green LED light rings placed on the camera lens focus light onto the cloth that is then reflected back into the lens. This instantly produces a very bright green colour in the camera that requires a tiny level of lighting compared to conventional methods. This is just one of the great developments that have been seen in this production method over recent years.
Why this LED chroma key
Traditional chroma key involves a complex professional studio setup with a large blue screen or green screen background. Whereas LED chromakey comprisesa range of flexible, portable, safe and easy to use products mean that with minimal lighting and technical expertise almost any location can be used as a virtual studio at a fraction of the usual costs – providing endless creative possibilities for digital content creation.
Typical cloth or painted green screen set-ups with big, expensive studio lights used in traditional system. You can also light up a traditional green curtain with simple lights bounced into an Umbrella to produce soft and even light. However, lights take energy, cause massive amount of heat and it takes time to create an even background with no shadows or harsh variations (gradations from a darker green to a brighter green). These harsh variations often times make keying traditional green screen in post a real chore.
Introducing LED Litering which mounts directly to the front of the camera. Believe it or not, these low powered LED’s provide enough luminance to light up a 30′ chromatte curtain from 30′ away.
When the light from the LED Litering hits the special Chromatte background, the light is reflected back and what the camera sees is a perfectly even blue or green sceen!
The background is a silvery graycolor upon initial examination. A closer look reveals tiny glass beads that reflect incoming light like “cats eyes” do when car headlights approach. This is what makes the material reflect the color of the LED Litering, in a brilliant blue or green.