What is a video green screen and how it can add more value to your video or image?
Green screen is a technique used in photography and film making to merge two entirely different images or frames. Green screen technology is also popular as chroma key, blue screen, color keying and color separation overlay. This technology has got huge popularity and usage after the evaluation of digital compositions.
Implementation of Green Screen technique involves in shot making and editing parts of film making. The basic process involves making a shot or image with our subject in the foreground and a huge green or blue screen in the background. Then taking another shot with the background we want and this time without our subject.
For example, if you want to make a film having a scene where a person (our subject) will be hit by a car. As it is practically difficult to make such a shot in reality, we will shoot the person “enacting like he was hit” with green screen or blue screen on background. Then we will shoot a car going on the road. So, basic principle is to merging two videos by replacing the green screen in the back ground of first video with the second video ( car on the road ). This process is called color keying.
So after making two different videos we can merge both of them with any popular editing software. It can be done in almost all editing or post-production software like Apple’s Final Cut Pro and Adobe’s After Effects.
The advantage of this technique is the you can choose what kind of back ground image or frame you want. Some times you can shoot both the shots individually and merge together (as I explained in the above example). And in some other cases you can merge a physically shot image or frame with a computer graphics generated image or frame. I will give you an example for the later case. If you want make a video involving a person in a bomb blast then, we can shoot the person with green screen on background and generate bomb blast with CGI and merge both of them.
Why Green or Blue? It is not a thumb rule that we cannot use any other color. But green or blue are preferred as these colors are in opposite hue to the human skin tone. Out of green and blue these days most of the film makers are going with green as the new generation digital cameras can capture green better than any other color.
Tags: Green Screen
