Chroma Keying with Keylight

Topics Covered in This After Effects Tutorial:

Creating a Garbage Matte, Using Keylight, Applying a Preset, Key Cleaner Effect, Advanced Spill Suppressor Effect, Matching Color and Tones

Exercise Preview

Exercise Overview

In this exercise you’ll key out a color screen so can add a new background to a video. This process is an example of video compositing.

Previewing the Final Video

1. Let’s see a preview of what you’ll be making. If you’re in After Effects, keep it open but switch to your Desktop.
2. On the Desktop, navigate to Class Files > After Effects Advanced Class> Greenscreen Removal > Preview Movie and double–click Woman Talking on the Phone.mp4.

3. Notice the following:

   • This video is composed of two videos that have been composited together.

4. Replay the video if you need to, and close it when done.

Setting up the Workspace

1. In After Effects, go to Window > Workspace > Standard.

2. Choose Window > Workspace > Reset “Standard” to Saved Layout.

3. If the After Effects window does not fill the screen, maximize it:

   Mac:	At the top left of the window, click the green button (the third button).
   Windows:	At to the top right of the window, click the Maximize button (the middle button).

Getting Started

1. In After Effects, if you have a project open, choose File > Save.

2. Choose File > Open Project and:

   • Navigate to Desktop > Class Files > After Effects Advanced Class > Greenscreen Removal.
   • Double–click on Greenscreen Removal—Started.aep to open it.

3. Choose File > Save As > Save As and:

   • Name the file Your Name—Greenscreen Removal.aep and
   • Save it into Desktop > Class Files > After Effects Advanced Class> Greenscreen Removal.

Setting up the Composition

1. Drag your main video (the one with the green or blue screen) into the empty Timeline panel or onto the Create a New Composition button.

2. Drag your background layer into the Timeline below your greenscreen layer.

3. Rename the bottom layer Background or BG and rename the top layer Talent.

Creating a Garbage Matte

Garbage mattes are quick masks around your subjects. They cut out any garbage in the shot that would make the keying more difficult such as light stands, rigging, or anything that isn’t the color to be keyed. They don’t have to be perfect just roughly enclosing your subject and limited the screen color to be removed.

1. Select your Talent layer. Thats the one with your main subject on it.

2. Activate one of the Shapes tools. The garbage matte doesn’t have to be perfect so you can use the Rectangle, Ellipse or Pen tools.

3. Create a rough mask around your main subject or subjects.

4. If necessary animate the mask if your subject moves around a lot.

Applying the Keylight + Key Cleaner + Advanced Spill Suppresser Preset

Keylight can be applied either as a stand–alone effect or as a part of a preset. Adobe has created a preset the combines the effects: Keylight, Key Cleaner, Advanced Spill Suppresser. In most situations it is best to use the preset rather than the stand–alone effect.

1. In the Timeline panel, select the layer you want to key out.

2. In the Effects & Presets panel, type keylight into the search field.

3. Double–click on the Keylight + Key Cleaner + Advanced Spill Suppresser preset.

4. In the Effect Controls panel, use the Screen Colour pipette to select the color you want to remove.

5. Adjust Screen Gain to increase or decrease the tolerance of the color removal.

6. Adjust Screen Balance if necessary.

7. Switch to the Screen Matte or Status preview mode.

8. Open the Screen Matte properties and adjust Clip Black, Clip White, and Clip Rollback as necessary. The goal is to have the foreground (what you want to keep) completely white, while the background (what you want to remove) is completely black.

9. Switch the View mode back to Intermediate Result and adjust Screen Shrink/Grow if necessary to remove any remaining fringe color.

NOTE: Chroma Keying is more of an art than a science. It can take multiple tries and often minor adjustments to values to get the result you want. It may take switching back and forth between the Intermediate Result and Screen Matte previews multiple times to achieve the effect you are looking for.

1. Turn on the Advanced Spill Suppressor effect.

   NOTE: For a complete list of the properties of the Keylight effect use this link for The Foundry’s own help page: https://tinyurl.com/2tr5w2fw

2. Save your file.