Chroma Keying - After Effects

In this article we will discuss how to chroma key out a background from your video. This works with any color, but a properly lite green or blue screen will yield the best results.

1. Bring in your footage to a new composition. In the effects panel search for the effect "Keylight."
2. Apply this effect to your footage by clicking, holding, and dragging this effect over the footage in the composition window.
3. In the effects window where it says "Screen Color" click the little eye dropper then click on the footage where the color you wish to key out is most prominent.
4. Click the little box that says "Final Result" and choose Status.
5. You will now see what is transparent and what is opaque in your footage. Black is transparent, white is opaque, and gray is in between. We want the subject to be white and the background to be black.
6. Twirl the triangle next to "Screen Matte." Increase the Clip Black until your background is solid black. Decrease the clip white until the subject is completely white. There will be a thin gray outline around your subject, that is ok.
7. From the drop down box select Final Result to see your final key.

To clean up rough edges use the Refine Matte effect, learn more about that over on the Refine Matte page.