Research and Understanding Green Screen

Green screen also known as chroma key is a "special effects /post-production technique for layering two images or video streams together based on color hues (chroma range)."
Mostly known to be used in the news and films. This technique is used normally for the budget purposes as it is cheaper using green screen technique rather than hiring or renting out a location.

Over the years green screen has became easier and cheaper to get hold off therefore even young teenagers who want to make short videos can do it by buying a green or a blue cover which they can put up on a wall. Also in the most recent times green screen can be made by number of video editing software which has the chroma key effect for example   such as "Autodesk Smoke, Final Cut Pro, Pinnacle Studio, Adobe After Effects" and Sony Vegas Pro.

Why the colour green or blue ?

Simple the colours green are blue separate from the skin colour of the human mostly therefore these colours are most often used.

History

The blue/green screen method was developed in the 1930s at RKO Radio pictures . A visual effects pioneer Linwood G.Dunn used an early version of the technique to create the wipe transition where it was used in films such as such as "Flying Down to Rio (1933)" .

Most credited person for the blue screen effect is Larry Butler who won an Academy award for special effects in the 1940 film "The Thief of Bagdad"

For some time matte shots had to be done locked down so that neither the matted subject nor the background could shift their camera perspective at all at any point . Later, computer-timed, motion-control cameras solved and fixed this problem, as both the foreground and background could be filmed with the same camera moves.

Through out the years the computer technology that is progressing made everything easier for the film makers to do. As green screen became a well known technique to be used in a lot of current and past well known films .

Films to of used green screen technique

Many films such as Titanic , Avatar and Spiderman have all used green screen . However one film I really liked and I thought it worked well in was 'The Avengers' . The film clearly had to use this technique as it helped it build what it is . The film is mainly focused and relied on effects. I think the green screen worked very well in Avengers as it made it seem very realistic which shows how much the technique of green screening has progressed over the years . In the video below you can see the amazing way they made the green screen effect work with the digitally made New York.