Most people know that not everything you see in a movie or TV show is actually real. Some productions, especially in the sci-fi genre, use a heavy amount of CGI. In order to create a particular spectacle, they use a technique called chroma keying. 

Chroma keying layers images on top of another to create a new image. The way that this is set up is through the use of a green screen. This lets filmmakers create visuals such as space battles and alien worlds without actually having to build them. Here are 35 green screen photos that show how Hollywood really works. 

2The Wolf of Wallstreet

Some directors choose to film boat scenes in the ocean while others prefer to shoot those scenes with the help of a green screen. For The Wolf of Wall Street, director Martin Scorsese decided to go with the latter. Although this detracts from the actors’ experience, it is more convenient to film.

The Wolf of Wall Street starred Leonardo DiCaprio and brought in a respectable $392 million (for a film of this size) at the box office. The film was based off a memoir by Terence Winter and actually sparked a lot of controversy among audiences because it was so mature in content.