How to Use a Green Screen for Online Teaching (Classroom Background)

Green screening was one of the movie industry’s best kept secrets for years. With current technology, anyone can easily set up a green screen and take advantage of the benefits of using them in the online classroom. 

There are so many ways you can use a green screen to take your lessons to the next level.

In this extensive post, we talk about everything you need to know for using a green screen for online teaching: how it works, the equipment and software you need, and tips for setting up your teaching environment.

And an add-on, we’ve compiled some nice classroom background you can download and use for free.

What is a Green Screen?

A green screen is a backdrop made up of a single color (usually green, but sometimes blue). It is usually made of fabric, such as muslin cloth. You can also make it from cardboard, canvas, and even use a green painted wall.

The green screen is used together with a technique called chroma-keying. We don’t go into the technical details here; instead, we’ll give you this to-the-point explanation from MentalFloss author Nick Keppler:

Chroma-keying is the process of isolating a single color or brightness value in an electronic image and then making that value transparent in post-production, allowing another image or footage to be placed “beneath” the color that’s been blanked out.

Although green is used so often that “green screen” and “chroma key” have become almost interchangeable, any color will work. Green is the go-to because it doesn’t match any natural skin tone or hair color, meaning no part of an actor will be edited out through chroma key.

Green screens are used in a variety of photo and video shooting scenarios; one of the more well-known uses of the green screen is the weather report on television.

The example below shows how chroma-keying with a green screen works. The green color behind the person is isolated, then replaced with another image layer:

Why Should You Use a Green Screen in Your Online Classroom?

Obviously, using different backgrounds during an online lesson will help you to deliver more effective and fun lessons, and compensate for the disadvantages of not being physically in the same room:

• You can use backgrounds related to the lesson topic to create an immersive learning environment.
• Instead of using props, you can show specific objects or situations in the background to explain concepts, elicit discussion and check comprehension; for topics such as geography, landmarks, landscapes, nature, food, and more.
• You can make your lessons easier to follow and show videos, presentations, or exercises, while your students can still see you on the screen.

Besides, using a green screen has some practical, not-so-obvious advantages:

• Your students can’t see your furniture, clothes, or personal items (or mess) in your home.
• Your family members or roommates can walk around the home without having to duck and crawl behind you while you teach online
• You can work from almost any location without your students knowing where you are.
• You can change up your virtual background without redecorating your actual work space.

Overall, a green screen will let you look more professional, create better results, help you get better ratings and thus, earn more classes.

In this article, you will find 18 best practices to increase bookings for your online lessons.

What Equipment Do You Need to Use a Green Screen?

Although a green screen setting is neither complicated nor expensive, you’ll need to invest in some equipment:

A Computer with Fast CPU and Sufficient RAM

It’s important to realize that software to use for chroma-keying your green screen background during a live online ESL lesson can be incredibly demanding on your computer’s processor and memory. You need to make sure you have a capable computer to handle the chroma-keying processes.

Our recommendation is to have a computer with at least the previous-to-current generation Intel i5 CPU running at 3GHz with no less than 4 cores, and at least 8 GB of RAM.

Important: With tablet computers and smartphones, you won’t be able to use a green screen.

Check out our recommended computers for online ESL teachers, all of which have the specs to perform well when using a green screen while teaching online.

The Green Screen

Green screens range from very cheap, to costly. You don’t need an expensive pro-grade kit. Indeed, many online ESL teachers make do with fabric they buy from the local fabric store. You can mount them on a stand or frame, or hang them on the wall or the ceiling.

Buy a green screen large enough to cover the area behind you adequately: It should be both wide and high enough to cover the entire area picked up by your webcam. Dimension requirements will vary for each person based on their height, work area, and whether you stand or sit while you teach online.

Here are a couple of affordable, recommended options available on Amazon:

Green Screen Studio Kits

The majority of online ESL teachers will be working from home. For those who have a spare room or home office where they set up their online classrooms, green screen kits are a quick, all-in-one solution.

Although the studio kits portable, they’re not really convenient when you change your teaching location frequently.

Collapsible Backdrops for Ultra-Fast Setup

If you teach online in your home with limited space, then your best option is to get a collapsible green screen backdrop. They can be quickly opened and closed, don’t require assembling or fudging around with separate stands, and can be stored away in a closet or in the basement when you’re not using it.

Portable Backdrops

Portable green screen backdrops are different from collapsible green screen backdrops in that they can fit in a suitcase, making them the ideal option for online ESL teachers on the road. You can hang them on a stand or wall behind you, or mount them on the back of your chair.

One major downside of portable green screens is that due to their compact size, you have to position them more precisely to fully cover your background. If you like to teach while standing, or even move around a bit, then this type of green screen backdrop is probably not the right item for you.

Green Screen Wall Paint

Though not for everyone, some online ESL teachers prefer not to mess about with positioning the green screen backdrop. If you have enough space and a wall you can paint, green screen paint is an excellent option. Even if you would rather not paint your wall green, you can get a wooden board, drywall or a thick sheet of cardboard to paint over.

The great thing about green screen paint is that you don’t have to worry about creases and folds, kicking or tripping over the green screen stand, or messing about positioning it. You just paint the wall, or lean the board against the wall, and you’re good to go.

Of course, painting a color across a wall or board means you will need to know how to paint, and to make sure the paint is consistently applied. You may also need to apply a few coats to the wall or board.

Lighting

Many people who use green screens will tell you that your lighting setup is more important than the green screen. When using a green screen for online teaching, lights serve two purposes: Illuminating the teacher and the green screen.

As you will discover when you set up your green screen in your work space, these two aspects will often conflict with each other.

You might find that your face and body in the webcam view are well-lit, but there is some fuzziness around your head. On the other hand, you might find that your face and body in the webcam view are well-lit with no fuzziness around your head, but there is some fuzziness around the ends of the green screen.

This fuzziness (often referred to as bleeding) is usually due to too much light on the green screen, causing the color to spill.

Both the amount of lighting as well as the color tones you use will play a role in striking the right balance. Different chroma-keying apps also handle the chroma-keying process differently. Ultimately, you will need to play around with your lighting setup until you get it just right.

Check out our recommended LED lights for online teaching to see which lighting options are best for your work space and green screen setup.

Chroma-Key Software

You will need an app that will chroma-key your green screen background. There are several free and paid apps available to accomplish this. What app you use will depend on your computer OS, as well as your specific needs. Some go beyond chroma-keying capabilities, like ManyCam Studio, which has an extensive set of features that enable you to show clip art, YouTube videos, add lower third text on your screen, wear a virtual mask, and much more.

The popular videoconferencing app Zoom, includes a virtual background feature that lets you skin your background with an image or video using a green screen, and if your computer’s CPU is powerful enough, you can skin it without a green screen. Zoom is an excellent app, but it’s only useful you’re using Zoom specifically for online teaching. If you use another platform, or if the online ESL company you work with has its own proprietary platform, you will need to use an app like ManyCam Studio, which creates a virtual webcam device on your computer that you can use with a green screen and more. Some teachers even use ManyCam and Zoom to access the additional features ManyCam offers while using Zoom.

Here is a list of apps that let you take advantage of your green screen:

ManyCam 

Price: starting from $39 per year or $79 lifetime for one device

Available for Windows and macOS

ManyCam Studio is designed to give you a suite of screen effects while live-streaming. Although ManyCam has a free version, to unlock the chroma-key feature, you will need to purchase the paid version. ManyCam has an impressive feature set that can transform how you teach online and interact with your students.

Open Broadcaster Software

Price: free

Available for Windows, macOS and Linux

OBS is a free, open-source software you can use to record and live stream your screen with a green screen background. Besides being free, OBS packs some really cool features, such as being able to set up multiple scenes, which means you can display images, videos, text, browser windows, and more, alongside yourself via your webcam.

Free is hard to beat, but you’ll need to rely on the community and a public knowledge base to get support if you need help. It’s recommended for more advanced users.

Video Meeting Software

Nowadays, most software for video conferencing has already built-in background-removal functions. They work even without a green screen – of course, with one, they produce much better results.

These software programs include the most popular ones:

• Google Meet
• Zoom
• Microsoft Teams

You can use all the video meeting solutions for free; however, for regular teaching, we recommend using the paid versions which offer more functionality and stable connection. Prices range from $10 to $20 per month.

Here’s how easily it works in Google Meet:

1. In a meeting, click on the menu item with the three dots in the bottom bar, then choose “Apply visual effects“ from the pop-up menu.
2. In the sidebar opening on the right, simply choose one of the default backgrounds images, or upload an image.

Google even offers animated backgrounds with birds flying around or with different weather outside – which looks simply wow!

You see the effect isn’t perfect in my example; I made the screenshot without using a green screen and proper lighting. (Still impressive how good it works nevertheless!)

In MS Teams or Zoom, you’ll find the background-removal functions analogously in the settings; it’s not complicated.

However, these video meeting tools don’t offer advanced configuration settings, so the results may not be as perfect as you expect. And you can’t use them when you need to teach with another software or with a teaching platform of your teaching company.

That’s why buying a software like ManyCam seems like a good investment; you won’t get broke from a $79 one-time fee. You can use it with any video conferencing tool or teaching platform, and tailor it exactly to your needs.

Setting Up Your Green Screen for Online Classes

Install and Run Your Chroma-Key App

The first step we recommend you take is to install and run your chroma-key app. Get familiar with the features of the app, so you can set up your green screen and lighting according to the functionality and recommended settings of the app.

Set Up Your Green Screen

Measure the area behind you that your webcam captures. An easy way to determine the green screen size you need is to use a spare bedsheet in place of the green screen. Use some measuring tape to measure the dimensions of the bedsheet that come into the webcam view so that you can figure out the length and width of green screen fabric you will need to buy.

You might need some help from a family member or friend to hold the bedsheet while you measure the area. A 6 x 9 feet (ca. 1.8 x 2.7 m) muslin cloth green screen should be sufficient for most online ESL teachers.

You also need to decide if you will be attaching or hanging the green screen to the wall, or using a frame to hold your green screen in place. We recommend using a frame, as this will make it easier to move around the green screen as needed, and won’t damage your wall.

After you have purchased your green screen, make sure it is free of creases or wrinkles by ironing them out with an iron on low temperature. Once you’ve done that, you can attach it to the frame.

Some green screens are set in a retractable frame, and if you are using one of these, then you can simply pull it open and lock into place.

Make sure your green screen is correctly positioned to fill up the area behind where you will be sitting or standing while teaching online. You will need to do this with your chroma-key app open on your computer so that you can view the area your webcam displays.

Set Up Lighting and Adjust Brightness and Positioning

Now that you have your green screen in place, you need to determine how bright your online teaching workspace is, and how many lights you need. If possible, choose LED lights with different color temperature settings, so you can increase or decrease brightness in different spots of your work space.

You will need to position and adjust your lighting with you standing or sitting in front of your computer with the chroma-key app open to preview yourself and your webcam.

You’re not done with lighting just yet. Next, we need to find and insert an image layer to replace the green screen behind you to test your green screen and lighting set up with your app.

Choosing an Image to Chroma-key

Although you can use any image to replace the green color in your green screen, we want to start with the most basic image that will enable us to test and tweak our green screen and lighting set up. For this, we can use a plain white image because a white image is void of any color, and will reveal any issues with light spill/bleeding.

Let’s see how to do this using ManyCam:

Looking for a plain white image to insert into your chroma-key app? We’ve got you covered. Click this link to download a plain white image.

If you see any fuzziness or bleeding around your head or on the green screen itself, you will need to check for and iron out any creases or wrinkles in your green screen, and reposition your lighting. Using the white background will also help you figure out if you need to get add lights to your setup.

This image illustrates how the white background will replace the green screen. Notice the slight green spill around the hair, body, and hands:

Note: If you have long hair, we recommend tying it back to reduce the green spill around your head.

Now, you are ready to use your teaching studio. Everything you need to do now is finding great images or other media to use to “decorate” your classroom background.

Classroom Backgrounds: Find Media to Use with Your Green Screen

As an online ESL teacher, you will constantly be on the hunt for media to use in your online classroom. A few excellent sites where royalty-free images can be found for free are:

• Pixabay
• Pexels
• Unsplash

These sites have a broad range of photos, illustrations, vectors, and videos to choose from, so you should have little difficulty spicing up your green screen images.

If you need some inspiration, look at these 10 great classroom images from Pexels we’ve selected for you as a starter:

Wrapping Up: Start Green Teaching

Now that you have a good idea how to use a green screen in an online classroom, get started! It’s really not as difficult as you think, it’s very affordable, and the difference using a green screen will make to your online lessons will be dramatic.

It might take you a bit of time to adjust your green screen and lighting to get the ideal setup. It will take you a couple of days to get comfortable using the chroma-key software. But within a month (or less), you will find green screening a cinch, and you’ll begin to wonder how you ever taught online lessons without one.