How to Choose Between Green Screen & Blue Screen for Chroma Keying Video [Reel Rebel #13]

Hey, I’m Stephen Schweickart with VScreen where you guessed it we do videos for companies. And,today, we’re going to be talking about the difference between green screens and blue screens.

So you watched some behind the scenes footage from a Hollywood blockbuster and you noticed thegigantic blue or green walls they film against. You may already know that they do this so they caneasily remove the color in post production and superimpose the characters onto a differentbackdrop, but what you probably don’t know is why they use both green AND blue and not just one orthe other. I’ll try and demystify this so whenever you want to insert yourself into a pool partywith a bunch of supermodels you can do so properly.

Let me play captain obvious for a minute and tell you the most straight forward reason to use blueor green. You don’t want to shoot on a blue screen if there’s a blue object in your scene, and thesame goes for green. Seems like common sense, right? If your talent is wearing a blue shirt infront of a blue screen, you’ll remove the shirt, and not in a fun way. You’ll be stuck with afloating head as your main character and likely that’s not what you’re looking for, unless you’retrying to be a silly weatherman. You can get around this a little, but stick with this rule ofthumb for now since you’re just getting started: If there’s blue in the scene, shoot on green.Easy peasy.

Now let me give you one that’s less obvious -- time of day of your scene. If you’re planning toput your characters into a scene taking place during the day, shoot them on green. Why? Becausegetting a perfect key in post production is very difficult for even the pros and in a daytime shotany edges of leftover green will be far less noticeable. The same goes for night and a bluescreen. You’d be able to see green spill plain as day in a nighttime shot, but the blue will bemasked by the bluish tinge of the moonlight.

One final thing to keep in mind when picking your backdrop color is how much space you have. Greenis the spilliest color out there because of how bright it is so it’s real easy to accidentallyhave your background color spill onto your talent and that can play havoc with your keyer in postproduction. Edges of your talent can easily be lost if you aren’t careful, especially with hair.Make sure that you have enough space between your talent and the green so that you keep as much ofthe green spill off of them as possible or you might jump off a bridge in frustration before youeven finish your piece.

There are more advanced reasons to choose one color over the other, but these simple rules shouldget you through the chroma keying battlefield with only a few bumps and bruises.