How Do Green Screens Work?

Posted on Jun 13, 2016
How Do Green Screens Work?

Is this a question you’ve asked yourself before? Yes, you’ve stood in front of a blank screen to have your photo taken and found the finished product to be of you floating in the middle of space with superheroes by your side? Fascinating and cool… but how does it work?

What Goes On Behind The Green Screen?

There really are superheroes out there, and they’re called professional photographers and videographers (who get way too little credit for all their awesomeness)! Yes, we like to think that we (the GlamCam team) fit that bill too and we have been credited with creating some of the most incredible ways to wow our event-goers and clients with high quality green screen magic.

The transporting of our clients to far-off lands and space encounters via green screen is made possible with a special effects process, referred to formally as chromakey.

Superimposing People On Virtual Backgrounds

Chromakey makes it possible for professional photographers and videographers to utilise the most advanced technology available today to superimpose their subjects onto a diverse number of distinctive virtual backgrounds. The actual process of chromakeying is the process of singling out a specific colour (the colour of the physical screen that you stand in front of) in an electronic image. It then uses computer software to make that colour transparent.

This makes it possible for another image – any image you want – to show through. A practical example is when a meteorologist stands in front of a green screen to present the weather. TV producers use chromakey to isolate the specific shade of green used on the physical green screen. Computers with amazing editing software make sure that the shade of green all but disappears. This allows for another image – such as the animated weather map – to appear instead.

When movies are filmed, the actor may be filmed in front of a green screen lying on his stomach with a large fan blowing his cape and hair back behind him. The chromakey process replaces the green background with a moving image of the night skyline behind the actor. This marvellous process makes it appear as though the actor lying on his stomach is flying through the New York City sky. Pretty cool, right?

Do Screens Need To Be Green To Work?

Screens don’t need to be green for chromakeying to work. Any colour can be isolated and removed using the chromakeying process. There are many photographers, videographers and filmmakers who use blue screens. However, chromakeying can also be used to remove purple, red, pink, yellow or orange backgrounds.

So why is green the most popular colour for screens? It’s a rather technical answer based on the concept of contrast. The screen that is used needs to contrast with the people being photographed. The shade of green used is a colour that few people are likely to wear, so it’s easier to isolate the green and make it disappear than many other more popular colours.

Should a person happen to appear in front of the green screen wearing clothing the same shade of green, chromakeying would make that clothing disappear too, leaving you with a bodiless head. That would be perfect for a Halloween event, don’t you think?

Give us a shout to discuss green screen options for your next event. We can go with anything from company branding to the Eiffel Tower, a Scooby Doo encounter or even a tropical paradise.

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