The Evolution of Green Screens

by | |

The Evolution of Green Screens


The Evolution of Green Screens

Hollywood movie magic has a new home — anywhere you want — and it’s all thanks to the power of the green screen.

Green screens and other chroma key screens enable you to picture yourself anywhere in the universe and turn that dream into reality with a little digital magic of your own. You can create a stunning YouTube video to gather followers or to build a new work presentation to crank up sales, train teams, showcase products and much more.

You’ve never been able to do more from your home or office, and we’re here to help you with that green screen journey.


How Green Screens Work

The use of a green screen, called a chroma key screen by people in “the biz,” is a method of placing two images or videos together to create a single image. Essentially you’re taking a video that will be your background and overlaying another image or video on top of that background.

The image being replaced, such as the green background, needs be a single, solid and uniform color. Next, technology associated with a live video feed — in the case of your local meteorologist pointing to a weather map — or a video that’s being presently recorded is used to filter out that color and replace it with your background image.

The area that isn’t edited out, green in most cases, is not impacted so you get a clear picture of both videos or elements. This is why sometimes you’ll see a newsperson have part of their clothing disappear on the news — it was too close to the screen color and got filtered out too!

Why do people disappear on green screens? Too close.

The technical term for this process is color separation overlay, and it works in a variety of environments. Neon green is easy for systems to differentiate and to filter out. There are also few natural items with this color, so there’s less of a chance that parts of your video will get unintentionally edited out.

Live feeds use chroma keying and a retractable green screen to do this video substitution, but it is also very common for your favorite TV shows to do this as well. For example, HBO’s “Game of Thrones” often has its actors interact with bright green objects or costumes that are digitally removed during production and replaced with dragons, snakes, the undead and much more.


Early Days of the Green Screen: Black

While green screen technology seems relatively new because it has a very heavy presence in modern entertainment, the underlying concept and similar technologies have been in use for more than 100 years.

Back in 1898, George Albert Smith was replacing parts of images using a double exposure, which had a black cloth in place of the green screen and used incredibly high contrast in the images to make the black elements virtually disappear. This technique made it’s jump to film in 1903 with “The Great Train Robbery” when it was used for static backgrounds in one of cinema’s first ever blockbuster films.

Frank Williams created a “travelling mattes” technique in 1918 that allowed the image replacements to move out of pure static backgrounds by compensating for the curve of an object, motion and camera movements. This was responsible for the techniques used to create the protagonist of the 1933 film “The Invisible Man.”


Early Days of the Green Screen: Blue

Blue screens were created by production teams at RKO Radio Pictures in the late 1930s and first made its way onto film with the special effect of a genie flying out of a bottle in the 1940 “The Thief of Bagdad.” The blue screen use was an evolution of the travelling mattes technique, and initially they were overlaid on stills to create transitions from one scene to the next.

A new device called an optical printer would work with two projectors, a beam splitter and a standard film camera to combine the actor who was working in front of a blue screen with a reel of an established background. This process was innovative, but somewhat slow as it combined the two reels one frame at a time.

The intensity of the blue in the blue chroma screen color was very close to that of neon greens, which eventually led us to the use of that very familiar green screen. However, there are still cases today where you can see a blue chroma screen in use rather than the more popular green chroma screens.


Early Days of the Green Screen: Disney Yellow

Sodium vapors were used in some filming during the 60s and 70s to create an intense yellow screen with an extremely specific wavelength, which made the substitution of a background much simpler. The camera for these films had a custom prism that would split the image it received and strip away the yellow, so the filmed action could be easily placed over an entire background.

This worked more as a removal than an on-the-fly replacement, and it was some of the most successful screen replacement technology of the time. You’ve probably seen it used to create twins in “The Parent Trap” or in a variety of dance scenes in 1964’s “Mary Poppins,” which won an Academy Award for its special effects.

But, the technology never caught on broadly. The reason, Filmmaker IQ reports, is that there was only ever a single prism designed to work with the ignited sodium vapor, and Disney owned it and the camera. To keep a hold on the technology, Disney charged a hefty fee for anyone who wished to rent the rig.

Disney charged a lot for yellow screens before green screens.


Early Days of the Green Screen: Green

One reason most of us associate the beginning of green screens with weather forecasters is because green screens were adopted in the early 1970s by both American and British TV networks. News stations had multiple cameras and displays so the weather person and other anchors could work in front of the green screen but look at a monitor of the feed to see the weather map they were pointing at.

They saw what those of us watching were seeing and it made the process much more seamless.

The technology we know today really got its start in the 1980s thanks to a man by name of Richard Edlund. For “The Empire Strikes Back,” Edlund created a quad-optical-printer that was able to interweave images from multiple reels much faster and much cheaper. His work was especially effective for miniatures and was able to work on both white and green backgrounds — for which Edlund received an Academy Award in 1980.

A big part of that development was the use of computers to control the processing of these images. Computers also allow production teams to better time the combination of the two layers, getting past many of the hurdles around movement and changes in camera perspective during a shot. Computers would control cameras with specific motions that mirrored each other so the foreground and background did not have a break in perspective.

Chroma key screens played an important role in color separation for analog color TV because the feeds were adjusted to the phase of the corresponding screen color to make in-phase portions of a video replaced by the background video. If the two phases didn’t line up, then the background video would not appear correctly.

In digital TVs, the process uses a numerical representation of a color or color range, and the chroma key screen and technology simply compares each part of the video with the number, replacing it with a background image when the color matches that value or is within a range of values.


Screens Today Are Blue and Green

We often call the process today “green screening” because of the fixed and retractable green screens we so often see in the behind-the-scenes and making-of parts of movies and TV shows. However, most of your favorite movies and TV shows will actually use a mix of green and blue screens whenever they’re doing work outside of a studio lot, such as on-site reporting or filming in a remote location.

Green screens dominate because they are the easiest to process technologically and few things have the natural green hue that need to be adjusted. Blue screens are common when the subject is predominantly green, so typically with plants and some animals or when an effect is introduced over the ground in a landscape shot.

Cameras are also more sensitive to green light, which is why the processing of green screens is easier. Digital cameras today have taken this one step further and are specially designed for green screen replacements. They do this by using a Bayer Pattern design that has twice as many green photosites than red or blue, making it easier to capture the green and maintain a difference between the green screen and green objects.


Faking It Like the Best of Them

The digital revolution has brought green screens out of the TV stations and movie studios into countless homes and businesses thanks in part to YouTube and a variety of affordable software editing packages and the use of portable and retractable green screens makes it even easier for everyone to utilize this chroma screen technology. You no longer need thousands and thousands of dollars to get your own setup for a professional look.

Software like iMovie, After Effects and Photoshop are so powerful yet affordable, that many of the green screen videos that go viral are filmed on a smartphone or tablet and processed in just a few minutes with your average PC.

To create compelling videos in your office or home, all you really need is a quality camera, regular PC, editing software and a high-quality green screen. Filming yourself in a static position will limit the bleed of background and foreground and today’s leading software has become especially adept at inserting the background properly because there is a high demand for the functionality.


Limit green screen background bleed by staying still.


Virtual Conferencing Roll Down Green Screens

One of our favorite uses for a green screen is to create a virtual background for an event or presentation — many companies are installing roll down green screens for this purpose. It’s why we stock a wide selection of virtual conferencing projector screen options that are designed for portability or to be firmly set in place with a size that fits your space.

Using a green screen for your virtual conferencing allows you to always be branded. We’ve seen clients successfully use them to show logos, run demo videos during a presentation and provide additional information — all while making sure the presenter’s face stays front and center.

Facial expressions are great cues that help others understand how to contextualize your words and can be very important to showcasing your excitement or concern, depending on the situation. As we know, eye contact is extremely important to your success when making a presentation. The use of a green screen helps to show your information — complete with the ever important eye contact — even in a virtual setting.

A bonus tip for those of you getting excited about sales and marketing opportunities with a virtual conferencing projector screen is to use part of the screen to give your audience a real-time clock that has your logo on it. This helps people stay on time, encourages them to full-screen your video and has a nice branding impact.

Another bonus is that all of the same equipment can be used for effective video ads, training, reusable presentations and much more.


Getting Started With Green Screens

The professional setup can be a little daunting for many green screen newbies, but there are plenty of affordable options for your company to test out a green screen production of its own. Your auxiliary systems and software don’t have to break the bank, which is great for anyone looking to maximize ROI, and that can free you up to afford a green screen that is the appropriate size to properly cover your entire background — one of the few absolute musts!

So, here are a few of the top tips you’ll need to get started:

  1. Lighting is a big deal. You need good lighting to look professional and to limit the amount of shadows you’re casting on the screen because that can reduce the quality of the background insertion. Get strong lights that make the green look smooth and even, with a preference for soft bulbs.
  2. Light the screen first. This helps keep things even and makes the whole process of a seamless background shift a lot easier. Next, light the front of your presenter, and then even everything out with additional lights as needed.
  3. Plan your action and movement beforehand. The one thing software can’t do is make up for any action that moves past your screen. So, if you stand up, spread your arms, kick a foot or move your head a lot, make sure you’re not exceeding the green screen — it’s hard to look professional when you lose a body part for a few frames.
  4. Match your setup to your person. People with blond hair have a hard time because the yellow can be close to a green, but you can avoid hair loss by matching lights to it on the other side of the color wheel, typically a magenta gel or filter. Jewelry and glasses can have the same issue, though they also tend to reflect into the camera and should be removed if possible.
  5. Having issues? Move forward. Getting closer to the camera and farther away from the screen will avoid a lot of lighting issues from strange glare, halos or shadows, all of which can hurt your video. Getting as far as 10 feet in front of the screen will make it a lot easier to adjust the background too, but it may require a slightly larger screen.


How to avoid green screen lighting issues.


Get the Screen You Need

The Projector Screen Store offers a wide range of portable and retractable green and blue wall or ceiling mounted screens designed specifically to work in your home, office or on the go. We have the size options you’ll need to cover your entire space and limit errors — like amputated hands in the middle of a shot — plus different control options from pull-down screens to 1:1 ratio designs perfect for your next presentation.

Order the screen you want online now, or use our online support tool. You can get help answering your questions so you can pick the perfect size, color and design of your retractable green screen.

This entry was posted in no categories.