Green screen or blue screens chroma key backdrops are sometimes used during filming in order to remove the colors when chroma keying in post production and superimpose the subject onto a different background or scene. On this week’s Reel Rebel Stephen Schweickart discusses the basics as to when and why you might choose to use one vs the other.
3 Tips/Considerations for Choosing Green Screen vs Blue Screen:
There are a variety of things to take into consideration when deciding on what color chroma key backdrop to use. Here are just a few basic considerations to follow when deciding which to go with.
1. Do not use the same color screen as your talent is wearing. If your talent is wearing green with a green screen or blue with a blue screen, when you remove the color you will also remove the clothing of your talent and will instead get the effect of a floating head and arms.
2. Consider the time of day. You should most always shoot in green if you are placing your subject in a daytime shot and blue for a night shot. Any leftover green that you are not able to remove will blend better into day shots, whereas leftover green screen will stand out against the blue hue that night time shots often have.
3. Be aware of how much space you are going to have behind your talent. Green is very bright and therefore has a tendency to "spill" onto your subjects. If there is not enough space between your talent and the green screen the result will be the edges of your talent being removed, especially around the hair.
There are more advanced things to consider when deciding on whether to use a blue or green screen, but following these few basic tips will at least get you started in the right direction.
Question: What additional tips do you have that may help those that are new to video production? AND, when do you think using Chroma key is appropriate?
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 the
gigantic blue or green walls they film against. You may already know that they do this so they can
easily remove the color in post production and superimpose the characters onto a different
backdrop, but what you probably don’t know is why they use both green AND blue and not just one or
the other. I’ll try and demystify this so whenever you want to insert yourself into a pool party
with 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 blue
or green. You don’t want to shoot on a blue screen if there’s a blue object in your scene, and the
same goes for green. Seems like common sense, right? If your talent is wearing a blue shirt in
front of a blue screen, you’ll remove the shirt, and not in a fun way. You’ll be stuck with a
floating head as your main character and likely that’s not what you’re looking for, unless you’re
trying to be a silly weatherman. You can get around this a little, but stick with this rule of
thumb for now since you’re just getting started: If there’s blue in the scene, shoot on green.
Now let me give you one that’s less obvious -- time of day of your scene. If you’re planning to
put your characters into a scene taking place during the day, shoot them on green. Why? Because
getting a perfect key in post production is very difficult for even the pros and in a daytime shot
any edges of leftover green will be far less noticeable. The same goes for night and a blue
screen. You’d be able to see green spill plain as day in a nighttime shot, but the blue will be
masked 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. Green
is the spilliest color out there because of how bright it is so it’s real easy to accidentally
have your background color spill onto your talent and that can play havoc with your keyer in post
production. 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 of
the green spill off of them as possible or you might jump off a bridge in frustration before you
even finish your piece.
There are more advanced reasons to choose one color over the other, but these simple rules should
get you through the chroma keying battlefield with only a few bumps and bruises.