1. What is Green Screen?

Most commonly used in television and movie production, green screen is a technology that allows subjects to be placed onto a virtual background.

Essentially, it is a type of Chroma key which uses advanced technology and subjects within the production is first filmed using a green screen background and then later, superimposed onto a totally different background, using advanced technology.

For instance, a little behind the scenes secret here, the weather reporter would stand to the front of a green background while filming, but what we see on our televisions, is the reporter standing to the front of weather maps. This is because digital processing allowed the solid green background, to be edited and removed, and a new background is placed behind the subject, that is, the reporter.

Chroma key technology, also known as color keying, is done using computer software, where the solid colored background is made transparent. Other images are made to show through this transparency, hence you see the weather maps instead of the solid green background.

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2. Why Are Green Screens Green?

Now you may ask, why only green and not any other color of the spectrum? Or why does the green hue work best with the computer software, becoming transparent, enabling subjects to be superimposed unto special effects?

Well, this is not absolutely true at all.

The term ‘chroma key’ and ‘green screen’ were so often used interchangeably, that the term stuck, but the truth of the matter is, any color will work. You can even test this theory on consumer video software such asMovavi Video Editor, which includes chroma key capability. This particular software would allow you to select any color background, to be removed.

Green was used popularly used because digital cameras were made to be more sensitive to this hue than any other color. Post-processing would allow for a much cleaner image than other colors.

This color was also a less common choice for clothing and hair, so actors could be safely edited out using chroma key technology, without damaging their image. When actors do need to wear green though, blue is the next best option and it is almost as common as green.

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3. Green Screen vs. Blue Screen: Which One to Choose

Deciding on whether to use a green screen or a blue screen would depend on the subjects and the colors that would be used during filming.

You should ensure that the colors in the foreground of your video are not in the same color range as your blue or green screenas seen on the photos below. If your subject has on the same color as the background, then parts of their body that has the same hue, would be removed during editing.

Consideration on the color outfit is not the only factor in your choice of using a green or a blue hue. Other factors such as the color of objects being used or the time of filming, play an important role in your option.

Look at this tutorial on YouTube. It gives you the rundown on why film producers use both backgrounds and not either or.

Here are a few reasons when deciding which is the best hue for you.

#1. When to Use Green Screen

Most modern digital cameras allow for more luminance when using the green color background and post processing is also the cleanest.However, chroma keying using the green background would enable clean editing but lighting from the green may cause the color to ‘spill’ over and reflect on the subject, making editing difficult.

By ensuring that your subject is acting some distance away from the green screen background, you can avoid the green from bleeding unto the actor.

Determining whether your scene is a daytime or nighttime scene, is imperative to your choice of hue as well since the ideal choice for filming ‘daytime’ scenery is by using the green background. During post-production, you would realize that for nighttime scenes, the green hue would be more challenging to blend into a darker backdrop.

#2. When to Use Blue Screen

As opposed to green screens, blue screens are ideal for nighttime scenes or for dark settings. This is because the darkness of the blue screen causes you to use more than twice the lighting as you would when using the green screen. For this reason, it is very unlikely that the light reflected would cause color spill.

Color spill from green screen backgrounds is time-consuming when editing your work and thus, correcting color from a blue screen would be cleaner than a green screen,making editing less challenging.

Even though you decided to shoot against a solid color background, whatever your choice in the end, it is always best to shoot in the uncompressed (RAW) format. This way, your images would have more data and keying out data in prost-processing would likely be easier and less time-consuming.

Animation World Network came out with a more detailed post on the technical aspects of the blue screen vs. the green screen.

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4. History of Green Screen

Origin

Green screen technology is basically an illusion, used to create special effects in almost every cinematic production of today. It all began in 1898 by master of illusion and film director, Georges Méliès. Wanting to create a scene which depicted a man removing his head, Méliès came up with a very meticulous technique involving multiple film frame exposures being combined. In this technique, parts of the camera’s lens were blocked, leaving certain areas blank. Alternative takes of the same scene that were filmed with a clear lens, were superimposed into these blank areas. The end result was a surreal illusion of what he was meant to depict.

Matte Processing

This technique was inspired by Méliès’ approach and were used for depicting scenes that were in either historical or faraway locations. Generally, several layers were superimposed unto the same frame so that objects could either be added or removed and specially made backdrops could be inserted to the back of the subject. Modern day filming still uses this technique, but it started the onset of the solid colored background.

Intervention of the Blue Screen

In the 1930s, chroma key technology was invented and this is where the history of green screen began. In the 1940s while filming The Thief of Bagdad, Larry Butler adopted a “blue screen travelling matte” as a single backdrop color. He had chosen this color because the skin colors of the actors were adequately different than the backdrop, allowing the foreground and background to be easily separated. Using this solid backdrop was so impressive that filmmakers adopted this technique to isolate their actors and create better special effects in post-processing.

Modification from Blue to Green

By this time, impressive special effects were being created using chroma key technology in a multitude of film situations. Filmmakers soon realized that digital camera technology was more sensitive to green backgrounds than the blue and was more suitable for post-processing. Most actors wearing blue clothing or who had blue eyes, appeared to be ‘disappearing’ during post-processing and so the green screen became the safer option.

Technological Advancement

Who Framed Roger Rabbit, an award-winning animation combined with live-action, used the green screen technology when it was being produced in 1998. The astounding special effects used, such as cartoons interacting with human actors, marked a new era for filmmaking and multi-million-dollar blockbusters began adopting the green screen effect for its versatility. This technology set its own trailblaze throughout the 20^th century and into today and while you may not be producing a blockbuster, you can still use this technology for any type of production.

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5. What You’ll Need to Get Started

This green screen process may seem complex and intimidating at first when you have to do the post-processing.

It really is simpler than you think!

There are several software specifically designed for this purpose and once you have access to digital video recording or photography, you can practically set up your green screen anywhere and start your own production.

Tools that you will need:

• Solid green or blue fabric
• Digital device, a camera or a mobile phone
• Lighting but natural light can work as well
• Chroma key software, usually included in most video editing software such as Movavi Video Editor

Remember, post-processing is the part that would involve you using the chroma key technology. Your first part of your production would be shooting your story on a screen. To get your green screen footage, follow these simple steps:

Step 1: Green Screen Backdrop

For this, you would need some green fabric, maybe even use a king-sized bed sheet. If you can’t find a suitable green hue around, you can easily purchase a piece of fabric at the store for as little as $10. Set the sheet or fabric up against a wall or hanging somewhere so that you can easily film your scenes in front of it. For a more permanent solution, you can have a wall in a room or in your studio painted green. You can even purchase a green screen from Amazon if you rather have one that you can easily log around to different locations.

Step 2: Check your Digital Camera or Mobile Phone

Most digital camcorders would allow you to save files in a format that can be easily imported into the chroma key software. You may want to ensure that your shooting device outputs at least HD quality, that is, 720p or higher. iPhones are also very good options.

Step 3: Setting up the Lights

Ever watched a film where the director said, camera, lights, action? Well lighting is important when shooting your green screen footage, but it is optional if you are using natural lighting. Ensure that the lighting wherever you intend to shoot, does not give you shadows on your backdrop. Go ahead and shoot your script!

Step 4: Install the Chroma Key Software

If you had success with Steps 1 through 3, then you are ready for the post-processing stage. Once you have your green screen footage, upload it to the chroma key software and place it on the track for editing. You would also need to upload your preferred background and place it on the second track. Once these both media are uploaded, simply turn on the chromakey filter and you can then further adjust it if parts of the green screen are still visible but adjusting the color settings.

If you are using Movavi, then you should only have to click a few times and the green screen would disappear.

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6. Tips for recording with a green screen

#1. Minimize Shadows

During post-processing, you would have challenges to edit out the shadows from the scene. It is better if you ensure you have adequate lighting because whatever is picked up by the camera, is interpreted as color, shadow included.

#2. Smooth and Flat Backdrop

To keep cost down, you may have improvised your backdrop by using fabric, paint or even paper. For a professional looking video, you need to ensure that the background is seamless, that is, no wrinkles or folds, even though you may think it would be edited out. However, the raised or crumpled texture can cause problems for the software when using it for post-processing.

#3. Turn Off Image Sharpening

Sharpening your image so that your subject looks better, caused difficulty for the chroma key software to separate the background from the subject. If your camera automatically sets to sharpen the image, then you would manually need to turn this feature off.

#4. Pay Attention to Props in addition to your Subject

While filming, we tend to pay more attention to our subject, but the props are just as important. Props can cause light to be reflected onto the green backdrop, causing challenges during post-processing. Also, ensure that your subject does not wear clothing that are almost the same color with the backdrop. For blonde haired subjects, you may want to use a blue screen instead or for use a magenta gel on the backlight that would change the color of the backdrop.