How the Green Screen Process Works
Green screen is the common name used to describe a special effects process formally known as chromakey. This process allows filmmakers to record a subject in front of a solid green background and then replace the background with another image during the editing process. Inside the editing software, the background color is selected and then any color matching that selection is made invisible by the software.
When the right green screen is used (and is evenly lit), and the scene is recorded with a good camera using the correct settings, the process can go very smoothly. When the recording is less than optimal (it is never perfect), the software must work harder to guess which colors are part of the background and which are not. The more variation there is in the color of the background, the less precise the results.
Green screen software tools have become very sophisticated at compensating for poor quality video recordings. But even the best tools struggle with fine hair detail, semi-transparent objects, motion blur, and other challenging images. The better your source footage, the better, faster, and easier your results.
Many video producers stop working once they have keyed out the background. But, professionals go through a few more steps to get amazing results. First, they color correct the image so that the subject and background blend together more effectively. Then, they add something called ‘light wrap’ to give the illusion that some of the light from the background is actually lighting the edges of the foreground subject – much like how light moves in the real world. These finishing touches create the subtle details that trick our brains into accepting the final image as real.
Lights, Screens, and Cameras
Most of your success producing green screen video footage comes from what you do before and during the video shoot. Your lights, your camera, and your screen (and how you use them) have a huge impact on your results. When you know how each one impacts the quality of the footage you record, you will be empowered to make the best choices available at any budget. Spend wisely and you can get great results with modest budgets.
