VFX Research - Chroma Key

A technique we are obviously going to be expected to researched is one of the most widely used since it's creation back in the 1930's and soon the be challenged the by its alter version in the 1950's. Used in pretty much every scenario that you would like to place someone in a virtual world, green or blue screens techincal term is actually Chroma Key.

"A digital technique by which a block of a particular colour (often blue or green) in a film or video image can be replaced by another colour or image, enabling, for example, a weather forecaster to appear against a background of a computer-generated weather map."

As mentioned in the definition, the technique allows you to render your block colour "(often blue or green)" invisible for the most part. Why though was it first invented green, and then also blue? Simple because bright green is not a commonly worn colour, anywhere. They are also specific shades that really don't clash with much else, skin has red tones all over the it they would disappear instantly with a red background; the same with hair especially lighter shades. Blue came into use because they found that it gave finer and less jagged when filming with actual film strips but as digital came to be green become most common again. The best part is you can pick rolls of this stuff up to cover plenty of space for less than £20 in most cases, it's so affordable.

Before going forward let's make sure we have the origins and developments correct, before digital compositing there was a technique known as 'Travelling Matte'.

"a film containing silhouettes of subjects or figures used to mask off selected areas during printing of motion-picture film."

This is typically how films incorporated the technique into film, but the process was incredibly time consuming which cried out for change. As mentioned above Green Screen first appeared in the 1930's and blue around the 1950's, simply to create basic and interesting backgrounds. In present day there aren't many high class films that won't use chroma key, only your lower budget or specific style films will get away with not using one but good luck to them.

With my new idea, I personally don't think I'm going to need to chrome key my subject. Being in a simple empty space she doesn't need to be seen anywhere, it isn't the location I am focusing on. Still it pays well to know the history and more of the inner workings of chroma key for future projects. I am still constantly searching for better plugins that enable me to work around chrome key, lately I have found that the Red Giant Suite has incredible software that makes the technique almost effortless; in the end that's what people want.