Do you want to know the differences between a blue screen vs green screen? Well, it may seem obvious – one is blue, and the other is green. But, of course, there’s a lot more to it than that.
Before we get into it all, blue and green screens are used as backgrounds for video production companies to shoot video against. Video editors can then replace the coloured background with a different image in post-production.
So if you want someone to stand in front of the Eiffel Tower, but you’re located in the US, you can achieve this using a blue or green screen. That’s one way to save on airfare!
What Is a Blue Screen?
A blue screen is precisely what it says – a blue screen. As previously mentioned, you use blue screens to replace them with an image of your choice in post-production.
Here are a few key features of a blue screen to take note of:
● The colour blue doesn’t bounce back much light as it has a lower luminance value.
● Because blue screens don’t reflect as much light, they’re perfect for low-light scenes.
● To properly expose a blue screen, you need a considerable amount of light, which can be expensive if you’re on a budget.
● The colour blue and blue tones are very common in clothing, which can make keying a nightmare in post-production.
And a Green Screen?
We think you can guess what a green screen is. Green screens work the same way as blue screens, except they’re green. Of course, there are some key differences between the two, but we’ll get into that later.
Here are some key green screen features to know:
● You can achieve a clean key with green screens as digital cameras capture more information on the green channel.
● The colour green has high luminance, reflecting more lighting, meaning you don’t need to blow the budget on lighting.
● Many programs have automatic green keying, which makes post-production simpler.
● Colour spill can be an issue because green reflects so much light. This means your subject(s) could have a green hue to its edges, making removing it a nightmare.
So, you know what blue and green screens are used for, but we know what you’re wondering: how is the background replacement actually done?
Chroma keying is the technique that editors use to replace the blue screen with a different image. This is where the solid background is removed or made transparent, allowing for compositing. Software such as Adobe After Effects and Premier Pro have chroma keying built into them.
It’s quite simple, and there’s also a reason the colours blue and green are used instead of yellow or red, for example.
It’s because blue and green are the furthest colours from human skin tone. That means it’s a no-brainer to use these colours for backgrounds because you don’t run the risk of keying out someone’s face!
4 Main Differences Between Green and Blue Screens
We’ve already gone over some of the differences between green and blue screens. But it’s vital you know the main differences, so you can make an informed decision on which screen to use in your shoot.
Trust us, if you choose the wrong one, everyone will know about it.
Blue is popular
Generally, the colour blue is more prevalent than the colour green. For example, your subject may be wearing a blue suit. Of course, if this were the case, keying out the colour blue would leave you with a head and a pair of hands. But if that’s the look you’re going for, perfect!
So, using a blue screen is fine, but make sure nothing is predominantly blue within the scene.
Do you want minimal issues when it comes to lighting your scene? Of course, you do. Do you want to save some of your budget for things other than lighting? Absolutely. So knowing that lighting a blue screen can be a little trickier is vital.
Blue screens have a lower luminosity than green screens. So they’re best used in low-light scenes. But this may not be ideal when you need to shoot a big and bright scene. In that case, a green screen is your friend.
We’ll assume you’re not using a Super 8 film camera and have access to digital cameras to shoot your footage. With digital cameras, a green screen is the way to go. Why? Because green screens don’t create as much noise as blue screens, and your editor will thank you for making their life easier in post-production.
Keying out the footage is cleaner and simpler with a green screen on a digital camera.
Colour spill is when the colour of the background ‘spills’ onto the subject. Even though you will remove the blue or green screen, there can be an obvious and unsightly spill around the edges.
Overall, blue screens don’t create as much spill as green screens, which is something to bear in mind.
When Should Blue and Green Screens Be Used?
How long is a piece of string? Like most things, deciding between a blue screen vs green screen comes down to the specific project. There’s no right or wrong answer, and it all depends on what you’re shooting.
The important thing is knowing when it’s best to use each screen.
So, use a blue screen when:
● Shooting objects with a lot of detail – colour spill is minimal with blue screens.
● Shooting dark or nighttime scenes as blue has a lower luminance.
● The colour blue isn’t prevalent in other items, such as clothing.
And use a green screen when:
● You want to use less lighting (for example, if you’re on a budget).
● Shooting daytime scenes as green has a higher luminance.
● You’re using digital cameras – keying out green is cleaner.
If you stick to these tips, you should be clear of any blue/green screen disasters. Happy keying!