How to Make a Green Screen on a Mac

Green screens are used in filmmaking to add backgrounds, animations and other characters into a movie. Green or blue are used to create the same effect. In the 1930s, a blue screen was used to create effects in the movie "The Thief of Baghdad." Green screens are also used in weather reports, movies, TV shows and commercials. You too can have a green screen on your computer. Read on to learn how to make a green screen on a Mac.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• iMovie

Making the Green Screen

1. Build a square frame for the green screen with the 2-by-4s. Make the screen large or small enough to fit your filming needs. The screen needs to cover the entire background of the shot.

2. Stretch the green material tightly over the frame. Smooth out any wrinkles in the fabric. For the screen to work you must have a completely flat screen.

3. Staple the material onto the frame, stretching it as far as you can to get rid of any wrinkles.

4. Place the screen on the stage and film the movie.

Work With the Green Screen on a Mac

5. Locate the "Library" folder on the Mac and open it. Search for a folder named "iMovie." If the folder exists, open it. If not, download iMovie and create a new folder named "iMovie."

6. Locate the "Plug-ins" folder. If the folder does not exist, create one. Click and drag the "SS Masks & Composting Document" from the desktop to the Plug-ins folder, if the document is not already there. When you download iMovie it places this file on the desktop if a "Plug-ins" folder is not already created.

7. Reboot the computer.

8. Open the iMovie program from the desktop and click "Import" to import the movie. You can import from any digital video camera into iMovie or use the program that came with the camera to save the file and then import it into iMovie.

9. Locate the section of the movie with the green screen. Click on it and drag it to the left side of the timeline. The time is at the bottom of the screen. Find the video that will replace the green screen on the right side of the timeline.

10. Click "Video FX" in the Editing menu. Select "Blue Screen" and then select "Smooth." In iMovie when you click these, the background picture replaces the green screen. Alter the green screen's inside fill, outside fill and choke until the videos' lighting and style match up. IMovie does not have a green screen feature, so you have to use the blue screen feature and alter the settings so the video looks right.

11. Click "Share" to save and export the movie from iMovie to a file on your computer.

Resources

• Download iMovie for Mac if you do not have it.