September 30, 2013



Two portable green screens available for checkout by K-Staters

By Phyllis Epps

The smaller green screen, which reverses to blue, works nicely for close upper-body views.

Equipment checkout in 213 Hale Library has added two large, portable green screens for K-Staters to check out. Each screen can be leaned against a wall or other support for videotaping, or users can check out a backdrop stand. LED lights, available from checkout, can be used to provide additional lighting.

The smaller screen, shown at right, is a 5-by-7 feet reversible green screen and blue screen. The larger green and blue screen, which is 7 feet wide by 9 feet high with a 7 feet deep floor overlay, is shown below.

These screens are used to make a background color — usually green or blue — transparent while another image layer appears in the background.

Larger 7x9x7 green screen for full-body images
The larger green screen, which is 7 feet deep and also reverses to blue, works better for larger, more immersive environments.

According to Wikipedia, chroma key compositing, also known as chroma keying, is "a special effects and post-production technique for compositing two images or video streams together based on color hues."

The technique can be used to remove a background from the subject of a photo or video.  The newscasting, motion picture, and videogame industries frequently use this technique.

It is commonly used for weather-forecast broadcasts, where a news presenter is seen standing in front of a large map during live television newscasts. In actuality, the presenter stands in front of a large blue or green background with the map superimposed on the background in post-production.

Software to do chroma key compositing is available on computers in the Media Development Center, 213 Hale Library.