This lesson we took a look at the use of green screens. There was not a lot I knew about green screens prior other than that they were green and that you stood in front of them and through computer magic, suddenly you're in Egypt. It turned out though that it was relatively straight forward. Using Adobe Premier Pro CS5 I learned that using a Chroma Key, I could pick out the colour of the screen and then gradually slide to remove it from the frame at the right level.
It was necessary then to be very careful with the lighting as shadows across the screen would make it harder to isolate all of the green. It was also worth considering how appropriate the lighting would be in relation to what you intended to replace the background with. As can be seen below, we went for a rather unrealistic underwater swimming theme but did place blue gels over the lamps to mimic the kinds of reflections.
At a more serious level these techniques could be very useful and I will most likely be trying green screen in relation to my actual video.