Green Screen

How Do Green Screens Work?

Green Screens work by combining images/video from two sources into a single image. The two sources are layered on top of each other, with parts of the top layer being filtered out to allow the bottom layer to show through. The green screen/chroma key filter that looks for and then renders transparent a particular colour (in this case, green). Green is often chosen because it is not a colour found in any human skin tones, thus preventing the people being filmed from being filtered out.

Screen Shot 2016-10-26 at 10.39.18 PM

How Do You Use It?

Depending on the program you use, the process may look a little different. It can be broken down into 2 main categories:

  1. Filming in front of a green screen with the desired image being superimposed simultaneously.
  2. Filming in front of a green screen with the desired image being superimposed later during editing.

Green Screen Apps

If you are unable to purchase an app, iMovie and other video editors are also capable of applying the Green Screen effect. You would need to pre-record your video or image, import it into the video editor of your choosing, and add your background/foreground images during the editing process. Here is a video tutorial for creating green screen movies in iMovie, and a text-based tutorial directly from Apple Support.

Tips for Effective Filming

If possible, your green screen should be placed directly against a wall. Not only will this prevent people from knocking it over, it will also prevent light from filtering through the back side of the screen which could affect the quality of your video.

Ideally, the green screen should continue onto the floor instead of just being on the wall so that students are able to stand “in” the scene, rather than just in front of it.

Green Screen Setup

The screen should be as smooth as possible, eliminating any wrinkles, folds, shadows, etc. that may interfere with the background. Additionally, ensuring that the screen is well and evenly lit will prevent distortion of the background or an uneven transparent effect.

Creating Your Own Green Screen

If you are interested in creating green screen video but don’t have a traditional screen, you can create your own using inexpensive materials. As long as the material you are using is fully saturated and opaque, it will function the same as a professional green screen.

You can use…

  • Plastic green tablecloth (available at most dollar stores)
  • Green shower curtain (from IKEA)
  • Green file folders (from staples; affixed together to be as large as you need)
    • Note: If there are any gaps between the folders or shadows from overlap, this may affect the transparency of the ‘screen’.
  • Pizza boxes painted green
  • Green trifolds (Michaels, Staples, etc.)
  • Thick green fabric (ensure the fabric is  taught so there are no shadows)
  • Green construction paper or Bristol Board

If you have a wall that you can paint, the best paints to use are…

  • Behr: Disney Gamma Sector Green
  • Sherwin-Williams: Neon Green (2032-10)
  • Valspar: Luscious Green (6010-7)
  • Dulux Colour: Chroma Key Green

Curriculum Connections: General

Language – Oral Communication:

  • Students will use speaking skills and strategies appropriately to communicate with different audiences for a variety of purposes.
  • Students will reflect on and identify their strengths as listeners and speakers, areas for improvement, and the strategies they found most helpful in oral communication situations.

Language – Media Literacy:

  • Students will create a variety of media texts for different purposes and audiences, using appropriate forms, conventions, and techniques.
  • Students will reflect on and identify their strengths, areas for improvement, and the strategies they found most helpful in understanding and creating media texts.

Science & Technology:

  • Communication:
    • Expression and organization of ideas and information in oral, visual, and/or written forms.
    • Communication for different audiences and purposes.
    • Use of conventions, vocabulary, and terminology of the discipline in oral, visual, and written forms.

Mathematics:

  • Communication:
    • Expression and organization of ideas and mathematical thinking using oral, visual, and written forms.
    • Communication for different audiences and purposes in oral, visual, and written forms.
    • Use of conventions, vocabulary, and terminology of the discipline in oral, visual, and written forms.

Social Studies:

  • Communication:
    • Expression and organization of ideas and information in oral, visual, and/or written forms.
    • Communication for different audiences and purposes in oral, visual, and/or written forms.
    • Use of conventions, vocabulary, and terminology of the discipline in oral, visual, and/or written forms.