Green Screen

Hannah Knipe

About Green ScreenChroma key compositing, or chroma keying, is a special effects / post-production

technique for compositing (layering) two images or video streams together based on

color hues (chroma range). The technique has been used heavily in many fields to

remove a background from the subject of a photo or video – particularly the

news casting, motion picture and videogame industries. A color range in the top layer

is made transparent, revealing another image behind. The chroma keying technique is

commonly used in video production and post-production. This technique is also

referred to as color keying, colour-separation overlay (CSO; primarily by the BBC, or

by various terms for specific color-related variants such as green screen, and blue

screen – chroma keying can be done with backgrounds of any color that are uniform

and distinct, but green and blue backgrounds are more commonly used because they

differ most distinctly in hue from most human skin colors. No part of the subject

being filmed or photographed may duplicate a color used in the background.

How did I set up green screen?

• Make sure there are no crinkles in the material.

• Then set up the lighitng.

How do I light a green screen?

• You will have two soft boxes lighting the green screen.

• Then a single light, lighting the model.

What is the point in using green screen in

your Web drama?• It is cheaper.• You can use any location you want

without having to actually go there.• You can exaggerate the size of

scenes.

Final image

What I did

You can see that I have used green screen to edit this

photograph of myself. I started by putting the photograph on photo shop and I then added

another layer of London I then had to put round to get

rid of the green screen and then merged the two

together so it looked as though I was in front of Big Ben.