How to Green or Blue-screen in FCP X

One of the great unsung features in Final Cut Pro X is the great new Keyer effect. In Final Cut Studio, there was a serviceable keying filter, and Motion 4 had the decent Primatte RT. The new keyer, present in both FCP X and Motion 5, produces better results with less work. Let’s take a look at how to use it in Final Cut Pro X.

Step 1 - Shoot your footage

Standard rules apply when shooting your footage: use the most expensive camera you have, light the backdrop evenly, and try to avoid shadows cast by the subject. A DSLR will produce much better results than, say, a DV or HDV camera, but if you have access to a camera with a better colorspace (4:2:2 or 4:4:4) then, of course, use it. Use a real green-screen fabric or paint in a controlled environment, or if you just want to test something and it’s a nice day, shoot yourself against a nice blue sky.

Shooting your video.

Step 2 - Import your footage

Import your video.

Nothing special here: Use Import from File or Import from Camera, depending on your workflow, into a new or pre-existing Event.

Step 3 - Create a new Project

Choose File > New Project. Again, nothing special, just make sure your project settings match your footage. We won’t be adding your footage as the first clip, so be sure to get this right.

Create a new project.

Step 4 - Add a Generator as a background

Green-screen or blue-screen removal implies you’ll be replacing the background, so let’s add that background first. Open the Generators tab by clicking on the small “countdown” icon on the Toolbar, second from the right of the seven small buttons. Drag the Blobs generator into your Project. (If you’re feeling adventurous, add a few additional ones into your Timeline after it.)

Add a background.

Step 5 - Add your footage to the Project

Select all or part of your source footage (using I and O to mark In and Out) and then press Q to Connect the footage to the background Generator.

Connect your clip.

Step 6 - Apply the Keyer effect

Open the Effects tab by clicking on the Effects icon on the Toolbar — it’s the leftmost of the seven smaller buttons. Under Video, click on Keying. Drag the Keyer effect to your clip.

Find the keyer effect.

Step 7 - Configure the Keyer effect

If your source footage was clean, you’re probably pretty happy already. The automatic correction is really very good, and there’s likely not much tweaking to be done. However, you can change a few settings in the Inspector. Open it by pressing the button all the way to the right of the Toolbar. 

Change the source color by clicking on the Sample Color thumbnail image, then dragging a new selection on the background. Adjust tricky edges by pressing the Edges thumbnail, then clicking inside the object and dragging to the outside, then moving the center line that appears between the two control handles.

Configure the keyer.

Other options here should mostly be self-explanatory:

• Strength controls how loose the color match has to be; the higher the value, the more will be removed
  
• View lets you see the composite, the grayscale matte that defines visibility, or the original clip
  
• Fill Holes makes partly transparent areas inside the foreground more solid
  
• Edge Distance makes the matte edges sharper
  
• Spill Level removes any color cast that the background might throw onto the foreground
  

Step 8 - Remove any unwanted objects

If you’ve been able to shoot cleanly, you’ll be able to simply crop out any lights, microphones, etc. from the edges of your frame. However, if you want more control, you can use the Mask effect. If you need to, open the Effects tab and drag it to your clip from the Keying section. In the Viewer, move the four points around to enclose the area you want to keep. 

A Mask applied.

It’s possible to use more than one instance of this effect to tackle a more complex mask, but you might want to use a third-party Eight-Point Garbage Matte, like this one from Alex Gollner.