Keying a green screen
It sounds simple in theory; place a subject in front of a green screen and, when you bring it into post with the click of a button, all the green is removed from the image. You can now place any background you want behind it. Unfortunately, rarely are green screens that simple. The color space of your camera, wrinkles in the screen, uneven lighting, and improper space between the subject and screen can all lead to problematic keys where several passes may be necessary in order to remove the color. Whether you have an amazing green screen or a bit of a puzzle to solve, Motion is here to help. It shares its Keyer with FCP X.
Getting ready
Find a piece of green screen footage on your system. Launch Motion and create a new project based on your clip settings. Make sure your playhead is at the beginning of the project. Go to the File Browser and find your footage. Click on the Import button to bring it into your project.
How to do it...
Let's add a filter to key out the green...
