Things you needGreen screening is actually quite simple. To successfully green screen, all you need are 2 videos or images, a green/blue screen and decent editing software.
Green/ Blue ScreenYou can purchase a ready made screen. No matter which color you are using, Green or Blue, they make sure that the color is pure and the same throughout the whole screen.
You can also make an inexpensive screen by using a table cloth or even a wall that is evenly painted and lit. Spend some time to remove dirt, discolorations, folds and wrinkles. Uneven colors in the screen will result in a video with floating objects and blotches.
The blue color is not necessarily better than the green color or vice versa. The choice mainly depends on the subject (the person or object in the foreground video).
It is important that the subject contains as little of the screen color as possible whether in their clothing or as part of an object. For example, if the person has blue eyes, choose a green screen.
Another handy hint while deciding the color is analyzing the color scheme of the video which will be inserted as the background. For example, if the background you are going to insert contains images of the sea, then use a blue screen.
If the background contains an image of a park or trees, use a green screen. This way you can hide and minimize the impact of the edges that appear due to non uniform or unevenly lit screens.
Proper lightingOnce you have decided on the color of the screen, the next step is to shoot the subject standing in front of it. For the best result , make sure that the subject has a well defined outline. There should not be small parts of the clothing or even hair hanging loose as you want a sharp separation from the background.
The camera's focus should be on the subject (and not the background), to prevent a blurry effect. Be sure no one's clothing matches the background color—if you're using a blue screen, and a man is wearing a blue tie, in the final movie it will seem that he has a hole right through his chest!
The lighting of your background is very important. It should be evenly lit. If it is too brightly lit, then some light will reflect off the background producing visible circles in the final combined movie. Also, make sure that the subject is not too close to the background screen. This is to avoid shadows, which disturb the uniform color of the background.
Since getting the lighting absolutely right is challenging, the easy thing to do is to shoot outdoors. The Sun is a great light source, as the distribution is even. Just make sure that no shadows fall on the screen.
Here is a short video that gives an example of how to green screen.
How to Make a Green Screen Studio -- powered by eHow.com
Applying Chroma Key Color TransitionNow, that you have created your video with the green/blue background, the next step is to use the Chroma Key Color Transition in Video Edit Magic.
This transition replaces the green/blue background with another video or image.
Superimposing two videos:
1. Add the video / image with the blue background to the Video 2 track on the Timeline.
2. Add the video / image you want to superimpose to the Video 1 track on the Timeline.
3. Position the Seek Slider so that it coincides with the point on the two videos from which you want the superimposition to begin.
4. Select the Transitions tab in the Collections window. Right-click on the Chroma Key Color icon and select Add Transition to Timeline.
An example of green screening can be seen in my video FIGMENTATIONS. To see this video just look on the bottom of the left side bar of this blog.
