4. January 9, 2011

Shooting and Editing Green Screen Footage

Opening Items

  • Free stock footage—it's real and it's free, but be sure to cancel within 7 days if you don't want to continue
  • Project 1 Rough Copy due February 27
  • Project 1 Review Comments due March 5 (prior to PL meeting)
  • March 5 Project LIVE meeting at District Office (Pine and Willow)
    • Optional free work session
    • Get help for your project
    • It's OK to bring a small group of students to help
    • Best chance to get it ready for iVIE
  • EYMF: Don't forget!

Film Featurette:

Green Screen Materials For Checkout

  1. 3 collapsible green screen backgrounds (about 3 feet x 5 feet; can be tough to fold back again)
  2. Green Screen Kit (this kit was recently praised by David Pogue in the NYT; good picture of how it should look).
    1. 8 feet x 9 feet green screen background (large enough so you can have part on the floor to include feet)
    2. 2 soft-box lights (makes the light diffuse, not harsh)
    3. 2 light stands
    4. 2 bulbs (HOT—be careful!!!)
      • 500 watt ECT bulb
      • B&H Link
      • Let cool before dismantling
    5. Training DVD (probably worth watching)
  3. Background Hanging Kit to hold the green screen from above
    1. You don't need to be near a wall
    2. 2 stands
    3. 4 poles across the top (use 3 of them for the kit above)

Work Groups

(Last Name: A-F)
 Molly Randy Cindy Olivia Stay here or go to the room based on last name (to the left)
 Samantha Kellie Crystal Dana 


  1. The Good News: Green Screening in iMovie '11 is a one-step process!
  2. The Bad News: Green Screening in iMovie '11 is a one-step process (hope you like it, because you can't change it; that's why it's important to film it well if you want good results).
  3. Top 10 Green Screen Filming Techniques
    1. Limit shadows and wrinkles (on the background)
    2. Keep lighting diffuse, not harsh. Typical classroom lighting does this pretty well (you may need to cover windows)
    3. Make sure subject has nothing green on (unless you want it invisible; think: disembodied floating head)
    4. Have subject stand at least 3-4 feet away from green screen; more if possible to avoid spill
    5. Avoid curly, frizzy hair (Yul Brynner Andre Agassi=Good; Don King=Bad)
    6. The less movement, the better
    7. Make sure all action to be included has green behind it, but it's OK if the edges of the frame don't have green. You can create a Garbage Matte to get rid of those non-green areas.
    8. If you plan on using extra lights, light the subject just as you would if it weren't Green Screen, but keep spill off of the screen (turn off green screen lights while you decide on subject lighting)
    9. Try to have your subject lighting similar to the lighting of the background clip underneath so the two shots look organic together (consider angle of light, intensity, color, etc.)
    10. Have talent leave frame at end of take for a second or two to film just pure background (mainly for iMovie)
  4. Important: iMovie > Preferences > General > Show Advanced Tools
  5. Adding background (warning: this must come first and there's no easy fix if you build the project wrong)
    1. I recommend laying out the whole project background clips first and then going back to add green screen clips; maybe put a title on clips that require green screen so you can easily find them
    2. If it's important, make sure your background clip starts on the frame you want; the end can be arbitrary for now.
    3. Tip: if you use stills, disable Ken Burns (Crop Tool>Fit)
    4. Remember to make frequent backups (File > Duplicate Project)
  6. Adding green screen clip
    1. Select portion you want to add (Tip: hit the "F" key to make this selection a Favorite so you can come back to it)
    2. Use the Zoom Slider  all the way to the left for precise alignment. Align the front of the clip.
    3. Drag onto background clip, let go, and choose Green ScreenTip: The Playhead tells you where the first frame will go; you may be able to hit the front on first try.
    4. Click right by the edit point and use the left and right Arrow keys to step through, making sure your subject is there in the first frame.
    5. If necessary, adjust which frames show by using the with Clip Trimmer 
  7. Adjusting length of the background clip: use the Precision Editor   on the Background Clip and enable Extras 
  8. Tip: Another option is to note the length of the green screen clip, double-click on the background clip, and change the duration to that of the green screen clip. It will add/subtract from the tail of the clip.
  9. Drag so the end matches your green screen clip, give it the Arrow key test, and click Done.
  10. Garbage matte, if necessary (watch for cut-offs); details how to do it in the Task section.
  11. Subtract Last Frame (worth a try, but I haven't seen much improvement)
  12. Adding music
  13. Exporting


Plan it Out
  1. Pick a background clip from the supplied folder
  2. Pick background music from the supplied folder
  3. Develop a scenario for your talent to act out that's appropriate for the background clip; make it FUNNY!
  4. Include dialog if you wish, but it's not necessary
Shoot and Build the Scene
  1. Film your green screen clip, following as closely as possible the best practices above
  2. Let the background clip you chose be your guide on length, but 10-20 seconds is fine
  3. Remember to have subject(s) leave view of camera at the end for a second or two (background only) before turning off camera so you can try "Subtract Last Frame".
  4. Create a new iMovie '11 Project
  5. Import your background clip from the supplied folder (File > Import > Movies) into a new (named) Event.
  6. Import your green screen clip(s) from the camera
  7. Add the background clip to the Project, then the Green Screen clip on top of it (see Instruction section above for details, if needed).
  8. Adjust end points (see above for process
  9. Enable Subtract Last Frame checkbox on Green Screen clip (double-click on it to reveal the Inspector); you can disable this if you don't like the effect by unchecking
  10. Cropping the clip: adding a garbage matte to get rid of unwanted items on the top or sides
    1. In the project window click once on the green screen clip (do not use the Crop Tool; use the Arrow)
    2. In the Viewer choose Cropped
    3. Adjust the 4 corner points so that any non-green elements are cropped out; watch out for cut-offs.
    4. Test your crop by pushing the Play button (top right, by Done).
    5. Click Done
  11. From a Finder window, drag your music onto the Project background (not onto a clip; background should turn green)
Publish your Work
  1. File > Export Movie > Medium
  2. Deliver to us on thumb drive
  3. Be prepared to talk about the good, the bad, and the ugly
  4. Re-assemble by 5:15 at the latest (we'll start earlier if all are accounted for)