Green Screen:
What They Are and How to Use them

Green screen production is the key to unlocking creative filmmaking without impossible set design. You don't have to take your actors on the high seas to film a dramatic ocean view, or book a destination villa for a beautiful backdrop. Green screens are used in almost every modern motion picture and is a landmark of television news casting.

A green screen allows you to put your actors anywhere, to create majestic backgrounds, layer live film segments over each other, and create an immersive multi-location shoot. You can add content or remove it. You can even put your actors in green suits and make them "disappear." But first, you need the right screen, camera, and software to make the magic happen. Today, we're spotlighting everything you need to know about green screen production to get started with your first Chroma-keyed video.

Let's dive into how green screens work and how to use a green screen in your video production.

Why are green screens green?

The first question most people ask about green screens is, "why green?" The answer is that green is the furthest hue from skin tones. This makes it possible to film people in front of a Chroma-keyed screen without risking any part of the person from being "clipped" or replaced with the overlaid image. This is also why it's important for actors to avoid wearing the color green and for green-screen set design to choose colors (even for plants) that are far from the neon green being keyed.

Historically, the movie industry has also used bright blue screens for the same purpose. You can still find blue screen as a green screen alternative in professional film production, photography studios, and streaming kits.

What is Chroma keying?

Chroma-keying is a method to layer two images or videos on top of each other. In simplest terms. The Chroma (color) selected in the top image is cut away to reveal the layered image or video below.

Every color has a Chroma range, which is where the technique gets its name. To "key" something is to adapt your video editing software to the "key" of your chosen "Chroma" in order to remove the background from the indicated color. Green screen editor software can then select the color you've keyed and the keyer will remove that color completely, so that these spaces are transparent.

Once the Chroma-key process is complete, another image or video can be laid "below" the transparent spaces to create a double-image from the weather forecaster's map to the fantastical scenes in modern cinema.

How using a green screen can benefit your video

How does a green screen work for video? Green screens can be used to benefit video production in many ways. It gives the director the freedom to create scenes and sets that would otherwise be impossible. Chroma-key production is not just for big filmmakers and news networks. Green screens are also making it possible for small studios and solo filmmakers to create incredible videos without the limitations of just your local set or props.

Destination shots without the destination

Green screen backdrops can be used to put your actors anywhere. The green screen effect makes it easy to cut out your actors and foreground set and place any destination background you want behind them. Your actors could be standing on a mountain top, on a beach, in the middle of busy traffic, or being stalked by a lion on the sunbaked savannah.

Green screen creates larger spaces

If you have a full-sized green screen, you can make your studio a hundred times larger than it really is. Give your actors space that doesn't exist by creating it in the green-screen background.

Fantastic and impossible CGI

You can make some really cool green screen effects by combining CGI (Computer generated images) with green screen projection/transparency. You film your actors in the foreground with a surrounding green screen. Then you can create any world you want around them. You can create fantastic worlds and events around real actors using green screen. Even with stock footage, you can still put your actors under the sea or standing in a volcano.

Resizing and green screen

Did you know you can also change the sizes of things using green screen effects? Many classic monster movie shots have been of normal things like insects zoomed in and resized to appear huge on a green screen - or shrunk to a tiny size - by overlaying one shot much larger than the other.

Green screen news casting effects

Then, of course, there are classic news casting green screen effects. The news uses green screens to show footage of current stories behind the newscaster, or to present the live weather map behind the meteorologist. Today, they can use entire green-painted sets to create a dynamic and interactive Chroma-keyed world.

Helpful tips for green screens

If you're not sure how to use a green screen, let's get started with a few practical tips.

Get the right size for your shot

You need the right size green screen for your scenes and planned shots. A headshot green screen kit is easy to setup, but not big enough for diverse shots. A room painted entirely green takes some maintenance to keep shadow-free. Drapery is the most high-maintenance of the DIY green screens, but also potentially the highest quality with the potential for a smooth green screen floor as well.

Light your green screen separately — and evenly

Always, always, always light your green screen separately from the subjects. The best lights for a green screen are even lighting so that shadows don't change your Chroma range for the keying. The subjects should be lit in the context of the scene, separately from the green screen entirely.

Pull your actors away from the green screen

In fact, it's a good idea to have your actors standing at least six feet away from a wall-sized or backdrop green screen. Four feet can be acceptable for a portrait green screen designed just for close-ups and talking head shots.

Use the least compression and highest shutter speed

Tip from a green screen pro: increase your video file quality with the minimum amount of compression and increase the shutter speed for more frames per second. This eliminates the risk of blur that could jeopardize the clean cutoff lines between your green screen and your subjects.

Avoid these common green screen mistakes

Green screen filming can be tricky. If your green isn't the same Chroma all the way across, or if there are too-compatible colors in the shot, you may see green screen errors when you go to Chroma-key the scene. If you're new to green screen effects, you can avoid a few rookie mistakes by learning from those green screen directors who came before.

Allowing your green screen to wrinkle

A DIY green screen backdrop made of fabric is prone to wrinkle. Stretchy fabric is the best green screen material, but a heavy drape that rolls out onto the floor is sometimes exactly what you need. Until it wrinkles. One wrinkle shadow in your green screen can alter the whole shot. Have a steamer and iron ready to keep a DIY green screen backdrop smooth and pristine for filming.

Lighting your green screen unevenly

Lighting on a green screen needs to be consistent and as even as possible. You may need several diffuse lights to achieve the effect while also lighting your subjects to fit into the scene you will be creating for them.

Dressing your actors in green — or using green on the set

Never have your actors wear the same color (or similar) to the green screen. Even a dark plaid can cause the "magically disappearing actor" trick where the Chroma-key picks up the color of a shirt or dress and your actor's entire body is cut away to reveal the background. This is fun for invisible stunts, but not if when your actor's shirt keeps blipping into the void.

You should also avoid green in any foreground set design. The wrong potted plant could suddenly become a leaf-shaped background cutout.

Avoid color spill with good green screen software

Spill is when a little of the green shows around your actors and set. This can be fixed most easily with good green screen editing software. If you find the Spill setting, you can adjust it to change the Chroma-key threshold for a crisper combination image.

Basic setups for green screens

Fabric, paint, or green screen kit?

Choose the type of green screen you need. The size and portability will play a major role. Green Screen kits are made of stretchy green (or blue) fabric that never wrinkles or shadows and is easy to set up, but tend to be smaller for close-up shots only. Paint can help you green screen an entire room and never wrinkles, but you'll be contending with corner shadows. A fabric backdrop provides the best quality and coverage, but takes constant wrinkle-care.

Fabric green screens: Know when to steam

If you choose a fabric backdrop, keep a close eye on it. One of the best tips we can give for green screen shooting is to keep your steamer and iron ready. Re-steaming the fabric to keep it smooth at the right moment can save your shot.

Separate and diffuse lighting

Keep your lighting setups separate—one for the green screen and one for your actors and set. Light your actors and set for the context of the scene: the time of day, the direction of the light, and any light-changing events. Light your green screen with an even, diffuse light so the entire backdrop is the same shade of green without shadows.

Always take test shots

Here's a pro tip: Always take test shots to determine if your green screen, lighting, and set are ready for production. A few test shots can ensure that when you and your actors get into filming, your time won't be wasted with a poorly lit green screen or accidental shadow creation. Block the scene, test the costumes, and use your green screen software to make sure the Chroma-key works perfectly with your setup.

The importance of proper lighting on a green screen

Proper lighting is absolutely essential for green screen shooting. Not sure how to light a green screen? The best lights for a green screen are diffuse, so there won't be a single bright spot that fades in a radius. Instead, you want your entire green screen to be as close to shadow-free as possible. Your lighting can even eliminate the shadow of the fold in a fabric green screen that extends to the floor.

Just like you can get a green screen kit, you can also find a green screen lighting kit to help you with the diffuse lights you'll need for even lighting. The most important thing is that you achieve the same shade of green throughout so that your Chroma keyer can find and remove the shade cleanly.

When to use a blue screen instead of green

Sometimes, you do need green in the shot. This is when you break out the blue screen for your Chroma key effects. The most common choice for a blue screen is when you are filming outdoors with trees and grass in the foreground that would be keyed if you were using green. You can also choose a blue screen if the script calls for an actor to wear green, hold something green, or interact with green objects on set.

What to look for in green screen editing software

Green screen editing is usually included in a high-quality video editing software suite. While some video editing programs only include the tools to clip, merge, and create transitions, video editing programs like Pinnacle Studio make it easy to select a Chroma-key setting and get started with green screen overlays.

Conclusion

Using the right green screen software tools, you can easily select the color and hue you want to Chroma key (green is usually the default, but you can also choose blue or even a custom Chroma key color) to remove the background and add something fantastic to the green screen areas of your original shot footage.

Ready to start your first green screen production? Good luck!