What we are looking for in a dramatic set is an imaginative substitute. Keep in mind, directors produce illusions. However basic the set materials really are, the end result can appear to the audience as the real thing.
Gerald Millerson, Author
The background is much more than whatever happens to appear behind the subject. It directly affects the success of the program, so it needs to be carefully designed and controlled.
Aspect ratio: Televisions have an aspect ratio of 4:3 or 16:9. It is important to keep the aspect ratio in mind when designing sets so that they fit the screen.
Chroma-key: Utilizing a production switcher, the director can replace a specific color (usually blue or green) with another image source ...