To make it simple: the chroma key is the technique we use compositing 2 images or video in 1 finale image.
The most common daily use is for weather broadcasts where the presenter is seen standing in front of a geographical map.
But one of the biggest markets is referred to the movie productions. How to forget about Forrest Gump with Kennedy? How they made it?
Simple, with the Chroma Key.
At the beginning the fav. color was blue, because of the film industry but in the last years we only use the green as a background color.
Also, the most important side is not just about the background but we must pay a lot of attention to the lights because it’s very easy to define a low budget production and a very good one just looking at how they used the lights making sure the shadows didn’t create any bad visual error.
I find the Chroma Key a fascinating world. The highest form of compositing.