Unless otherwise noted all text, pictures, captures and illustrations are by Mike Strong. Copyright 2003 - 2017 Mike Strong, all rights reserved.

Video Editing and Shooting - Block XLIII (43)

Digital Video Editing

Chromakey

Chromakey is one of the many effects offered in Vegas Movie Studio (VideoFactory 2) after purchase by Sony). To see the other effects click here.

Chromakey allows you to place someone, such as our sturdy friend Kung Fu Hamster! in any scene.
To play the Kung Fu clip: RealMedia: 56kb, 128kb.

Here is our starting hamster. We shoot him against a green background. You can purchase seamless paper in Chroma Key Green (called "Stinger") & Chroma Key Blue (called "Royal Blue") from camera stores selling "Premier" brand seamless. This example used some cheap green paper (a couple of dollars) from the educational/teacher supplies section of U.S. Toy Company in Lenexa, KS, just to show that you don't have to spend the hundreds of dollars that Chroma Key background cloths will cost you. At Overland Camera Store in Overland Park, KS the seamless rolls cost $27 in 53-inch wide size and $50 in 9-foot wide size. A similar size cloth background may cost $300-$700 locally. Buy the paper.

 

To start the project create two text clips, one for your name and one for the title which says, "Chromakey Example"

Files specifically made for this exercise are on the class data DVD or may be downloaded from this page:
Download Video Exercise Files Here

 

Click on the "FX" box in the lower right of our hamster's clip. Click in the effects list on the left, on the "Chroma Key" option - hold down the mouse and then drag it onto the effects dialog. When done it should look something like this.

Now, click on the small eyedropper button in the Chroma Key dialog. The cursor will change to an eyedropper shape. Move the cursor to the preview panel and click on the color you want to matte out.

Note about Green Screen and Blue Screen: Blue screens were common for many years. In the last decade they have been almost totally taken over by Green Screens. Our eyes are more sensitive to green and video color information is usually stronger in the green channel. The best chromakey effects use a color which is very strongly represented in the picture. The solid-color background behind our subject is background paper. You can actually choose a lot of different colors but special shades of green are made just for this purpose. Check with your local video/photo store.

Once you click with the eyedropper the chosen color will be dropped out. It goes to black as you can see here. This black is really a "transparent" color.

Now, place your background clip or picture in the video track under the track with the transparent background. The editor will immediately shown them combined as in this picture.

Here is our background picture. This is my own car at a country club. An errant golf ball found its way to my car's windshield as I drove northward on Metcalfe. With the club manager's help I was able to locate the golfers who paid to replace my windshield.
Lucky I didn't sic Kung Fu Hamster on them.
Starting Image Masked Video Combined with Background

Play the clip: RealMedia: 56kb, 128kb.