| There's nothing quite as magical as being able to | | | | techniques of special film and filters, using black |
| juxtapose images, scenes, and people into the | | | | and white negative images were used to extract |
| composition you are creating. It is the key, pardon | | | | the subject as carefully as possible from the 'blue |
| me, of creativity. While we associate keying with | | | | screen'. As this technique was developed, much |
| our modern film and digital composting, 'chroma | | | | simpler more commonplace applications became |
| key', 'color keying', 'blue screen' is actually a | | | | popular. The 'meteorologist screen' uses the same |
| relatively old process dating to the very earliest | | | | technique to allow the weatherman to stand |
| movie and television productions. | | | | before his weather maps when he shares the |
| In the 1930's two techniques were created | | | | weather news with us. He is filmed before a blue |
| simultaneously that are fundamental and widely | | | | screen, then placed on a weather map layer. |
| used for creating virtual video and animation, the | | | | In it's most sophisticated stage, the older forms |
| use of 'mattes' and 'keying'. The matte then as | | | | of keying required several steps of film |
| now is simply creating a scene to be projected | | | | development, processing the matte and blue |
| 'on top of' the subject, 'behind' the subject. | | | | screen extraction, synchronization of the two to |
| Concepts such as cut outs, literally painting a | | | | produce a seamless product. Fortunately for us, |
| background onto glass that was placed before the | | | | After Effects has a category of keying effects |
| camera during the video shoot and in our world of | | | | that allow us to create very credible results in |
| After Effects creating a 'matte layer', 'mask | | | | only minutes. One of the most highly |
| matte', create the illusion of this imagery as the | | | | recommended is the KeyLight tool from the |
| true background of the video. This allows your | | | | Foundry: |
| actor to be in African jungles, atop great | | | | There are many great tutorials available for |
| mountains, and standing before stampeding | | | | keying basics and KeyLight in particular. One of |
| buffalo. | | | | my favorite is by After Effects guru Chris Meyer: |
| The companion technique is the 'blue screen', the | | | | You will find the basics of keying easy to |
| keying. Whatever your subject is doing, he/she | | | | embrace, and the tools available to apply these |
| must be cleanly separated from their true | | | | techniques allow you to focus on your project, |
| backdrop to be realistically placed against the | | | | imagination, and possibilities instead. In my next |
| matte layer. The actor was photographed against | | | | article on keying, I will focus more on the tool, the |
| a blue background. This blue or green background | | | | steps, and the considerations that help you |
| was chosen primarily because of the contrast to | | | | sharpen your technique and create a more |
| human skin color. These colors made it easier to | | | | credible key. |
| separate the subject from the background. Subtle | | | | |