If necessary, choke this matte further to eliminate tracking markers and other small bits of noise.In Keylight Status or Combined Matte view (depending on your preference), raise Clip Black just enough to remove gray pixels from the background in Status view, and then lower the Clip White setting to just above the same number ( see Figure 8).To create this layer, follow these steps: The goal with this layer is to create a background matte that's 100% transparent and outside of all edge detail by several pixels. For clarity's sake, turn off effects for Edge for the moment. Duplicate this layer (Keylight still applied), rename it Background, and solo it.(Enable Move All Attributes in the Pre-compose dialog box.) Rename the layer Edge. Create a pre-comp containing the Keylight layer created with the previous steps.This breakdown will work with any software keyer, but it's especially helpful to get the most out of Keylight. The three-pass method is the same principle, but it should save you from extensive hand-animating. Keylight's Inside Mask and Outside Mask controls let you draw a mask, set it to None, and then select it as an Inside Mask or Outside Mask.

This method of isolating and focusing on the edge inspired me to devise the following workflow to achieve the same in an After Effects pre-comp, with as few extra steps as possible. The Apple Shake-based implementation of Keylight adds inputs for a garbage matte and holdout matte.

Finally, from the drop down View box, select Final Result to see your final key.Figure 7 Nice edges-it's the core of this matte that needs to be a little firmer.

There will be a thin gray outline around your subject (which is okay). Decrease the Clip White until the subject is completely white.

Twirl the triangle next to Screen Matte and increase the Clip Black until your background is solid black.

We want the subject to be white and the background to be black. Black is transparent, white is opaque, and gray is in-between.

You will now see what is transparent and what is opaque in your footage.

Then click on the little box that says Final Result and choose Status.

Then click on the footage where the color you wish to key out is the most prominent.

Now, in the Effect Controls window on the left of your screen, where it says Screen Colour, click on the little eye dropper.

Apply this effect to your footage by clicking, holding, and dragging this effect over the footage in the composition window.

In the effects panel search for the effect Keylight (1.2), which is under Keying.

Bring in your footage to a new composition.

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

Keylight 1.2 not working