Green Screen

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During Destination Week 3 we discussed several ways to produce media. I ran a session on creating media with green screens. This technology leverages a computer’s ability to display pixels as totally opaque (full opacity) or totally invisible (full transparency). If you’ve ever created a photo slideshow with cross dissolves, you have seen how a computer is able to slowly fade an image to nothing as a new image fades up to replace it.

In the case of doing this with green screen, there is one small difference. Instead of setting an entire image to full transparency, we are setting only pixels of a certain color and brightness to be invisible. We can do this with any color, but it’s common to use green or blue screens since those are the colors furthest away from human skin tones. Having that color separation makes it easier to isolate people from the background. The result is a image or video that has some pixels visible and some invisible.

What can we do with such images and videos? We looked at several examples of how we might use such assets to improve student learning.

The key to getting a good green screen is to have bright, even lighting on the surface of the screen, and to try to keep subjects far enough in front of the screen that light doesn’t reflect off it and ‘spill’ green light onto them. The screen can be an inexpensive piece of cloth, or sheets of poster board. You can get fancier backdrops by visiting your local faculty resource center and checking out one of the do-it-yourself video kits or reserve a green screen room at the Osceola Campus learning support center.

You can also download inexpensive phone or tablet apps that allow you to shoot, edit and distribute green screen video using a single device. We looked at both Green Screen by Do Ink and Green Screen Movie FX. Once you are comfortable with the basics, you might try getting an inexpensive green screen monosuit so you can create levitating objects within your frame.

3 Responses to “Green Screen”

  1. bsartor

    Very informative. The use of ‘green screen’ seems to be limitless!

    Reply
  2. dhodges6

    So innovative-especially how to integrate the screen with ideas to interest students!

    Reply

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