Green Screen Composite Photography
I had the good fortune to work with a beautiful young model this week and do a creative green screen photo shoot in my studio.
Green screen technology is most commonly used in cinema and TV - you see an example of it every evening if you watch the weather report on your local news broadcast. It's pretty simple - a elastic sheet (elastic is important because you don't want wrinkles in the screen) or painted surface such as a wall is colored a very specific color of primary green.
It has to be uniform and the hardest part of making a green screen work is lighting it consistently. You film or shoot whatever photos you are going to shoot/take - and the next most important thing about green screen usage is getting good separation between your main subject and the screen.
You do NOT want any green light to splash off the screen onto the actor/model. So you need to understand lighting - key/fill/background/back light - I often use a 5 or 6 light setup. Sometimes I use more. After you've taken your photos or shot your video/film footage, the images with the green screen are brought into whatever software you are using and a "CHROMA KEYER" is applied. What a chroma keyer does is identify the specific green of the screen and makes that color unavailable - thus making it invisible. Now you have your main subject floating in space and you can put whatever background you want behind them.