Do Chroma Key With Final Cut
The ability to replace any given background with another image is a commonly used special effect. “Chroma key” refers to shooting the subject in front of a solid color, then using editing software like Final Cut Pro to replace the solid color with another image. Green or blue screen are the most common colors used to create the key effect. Chroma key creates the illusion a subject is in another location. You can also use the chroma key effect to insert digital backdrops that create a kind of “virtual set” the subject appears in front of.
1. Choose bright green as your key color. Technically, the chroma key effect will work with any solid color. Green screen is the most popular choice for chroma key effects used by professionals because the bright green is least likely to appear in wardrobe selections. Nevertheless, be sure your subject is not dressed in a lot of green to avoid complications when setting up your key effect in Final Cut.
2. Light the backdrop evenly. For the effect to work best, the green screen backdrop must be well lit and the lighting must be perfectly even across the entire backdrop.
3. Place the subject far enough in front of the backdrop so that light from the backdrop is not reflected on the subject. If the subject is too close to the backdrop, the green light reflecting off the backdrop onto the subject will make achieving the key effect more difficult.
4. Assuming you have properly set up the shooting environment and recorded your video, accomplishing the chroma key effect in Final Cut will go smoothly. Open Final Cut and import your video. Also import the image or video you want to key into the background.
5. Move the background image to the V1 track in Final Cut. Add the video you will apply the effect to into the V2 track. Double click the video clip on the V2 track so it appears in the Viewer.
6. From the Final Cut menu, select “Effects,” then “Video Filters,” then “Key” then “Chroma Key.”
7. If your subject is not visible in the first frame of the clip, place the cursor in the timeline to where the subject can be viewed in front of the green screen. Select the “Chroma Keyer” tab from the Viewer and locate the eyedropper on the right edge of the tab window. Place the eyedropper on the green screen portion of the clip in the Sequence Viewer tab. The background from the V1 track should now appear.
8. Use your effect controls in the Chroma Keyer tab to fine tune the key as needed. The remaining green pixels surrounding your subject can be reduced or eliminated by adjusting the Edge Thin and Softening sliders.