What is a green screen studio
NOTE! The film has no sound. It only shows how to replace a background.
In a green screen studio, you can use a technique for visual effects where a subject or object is filmed in front of a single-colored, usually light green hue. This process makes it possible to remove the green background from the image and then replace it with another background, which can be a still image, animation, or film. In the example above, the background is a digitally produced studio.
Why the color green?
There are two reasons why we work with the green color (although other colors are possible). The first is that the light green hue is not found in human skin tone and is rarely used in clothing, so it's a "rare color" and since everything in that color hue becomes transparent in the process, it's obviously good if it doesn't exist in the foreground object.
The second reason (at the risk of being a bit nerdy here) is how colors are compressed when recording digital film or video. A common color compression is called 4:2:2, where the numbers represent the color channels red, green, and blue (R:G:B), which means that the green color channel is intact and that 1/2 of the red and 1/2 of the blue color information has been discarded. Oddly enough (even if it sounds like a lot), we don't notice the loss of these colors because our eyes are not as sensitive to red and blue color spectra as they are to green. For various reasons, the human eye evolved with excellent detail resolution in the green channel but rather poor resolution in red and blue. So when you need to remove the green color (also called "keying"), it's extra beneficial to work with the green tone so that it contains twice as much information to work with as the blue and red channels, thus providing the greatest possible contrast against the foreground.
Are green screen and chroma key the same thing?
You may have also heard the term "chroma key" in connection with green screen filming. Chroma key is a term for the method of removing a specific color in video material; "Chroma" comes from the English term "chroma range", which means color range. The word "key" is used for the method of removing a color from a color range, so that "to key" or "pull a key" in connection with green screen simply means removing the green color.
Why use a green screen studio in film production?
A green screen studio in film production is a great tool for us filmmakers, as it contributes to creative freedom in post-production (post-processing). The ability to choose, change, or adjust the background eliminates the need for expensive film recordings at "real" locations and also allows for the creation of non-existent environments, so-called virtual backgrounds. See example below.
When shouldn't you use green screen?
In certain scenarios, there may be a need to capture the real environment where the subject is located, where green screen is not suitable. Additionally, if the scene requires a high degree of visual complexity or details - such as reflections and shadows - green screen technology is unlikely to produce an acceptable result. It can also be that the scene contains significant saturation and hue shifts in the background scene, which can cause chroma key artifacts when composing with the foreground element.
What characterizes a good green screen studio
A good green screen studio is characterized by its ability to provide the optimal background for chroma key compositing. This requires a solid, evenly lit background that can be seamlessly blended with other video elements in post-production. Studios built for green screen production must also have the lighting required to ensure that foreground subjects are correctly and consistently lit, without creating any unwanted reflections on the green screen background. Having a well-insulated studio with sound-absorbing material also helps minimize ambient noise and unwanted acoustics.
Do you want to produce film with the help of green screen?
We have extensive experience producing film with the help of green screen and are happy to assist with production if you need to produce film with virtual backgrounds or other special effects. Contact us, and we'll tell you more.