Perhaps on your various adventures across the internet, you’ve encountered a video along the lines of the one to the right.
Maybe it was video your teacher made for a class, a twitch stream, or a vlogger. Regardless of where you saw it, the creators were most-likely using a greenscreen to accomplish this effect. If you are interested in reproducing this look in a creation of your own, well, look no further, because this blog post will give you the rundown on how to accomplish this for any budget. Ready? Lezzgo.
Using a greenscreen for video production (or, as I like to call it, “greenscreening”) is a technique for combining two sources of video input, where one appears to be super-imposed on the other. It allows the creator to insert one or more people or objects “on top of” or “in front of” another image or video feed. Greenscreening is used all over the place, from big-budget movies to, teaching demonstrations, to the weatherman on the evening news.
So how does it work? Generally, one video feed acts as the foreground (which is the one with the greenscreen in it) and another as the background. Both of these videos are fed into some type of computer software (there are lots out there, more on that later) to be combined. The background feed will be placed first, with the foreground feed on top of it, blocking the background. Then, in-software, the green pixels from the foreground are made invisible, to reveal parts of the background.
The image to the right shows an example from the avengers. The top image shows the original video recording with Thor, Captain America, and Black Widow in front of large green screens, pretending to shield themselves from an explosion. Later, in post-production, a video of an explosion (along with some other video effects) were added in to the background.
Though you do need a multi-million dollar budget to cast Chris Hemsworth, Chris Evans, and Scarlett Johansson in a feature film, you don’t need one to get a green screen up-and-running at home. In fact, you can get one working for (almost) free, assuming you already have a computer with a decent webcam.
As with many things in life, you get what you pay for. You can spend hundreds, or even thousands of dollars on greenscreen setups that will give you great image quality, lighting, and clarity. Though I will talk about more expensive setups later, for now I’m going to show you how to get a bare-bones, ultra-affordable greenscreen setup working. In this section, I’m going to assume that you already have the following:
If you don’t have a webcam, you can pick one up fairly cheap online. As you might image, there are a lot of options out there for this. One that seems to be popular as of this writing is the Logitech HD Pro C920. Even if you have a built in webcam on your laptop or desktop, you might want to get a USB one anyways. It will give you more flexibility to position the camera independently of your computer.
The other purchase that you’ll have to make for this is the greenscreen itself, which you will need to hang/mount behind you. There lots of options for this, including:
(to be clear, I’m not officially recommending any of these products in-particular, just giving you some ideas). Whatever methodology you choose, it is important that the end result is a nice, evenly-lit, medium green color without and wrinkles or major shadows. I also want to stress that bright, even light is important here. A good way to accomplish this during the daytime is to have your desk positioned in front of a window, which provides a large, hopefully even, light source. Otherwise, work with the lamps and other light source that you have to get things as even as possible.
After you’ve gotten your greenscreen set up, spin up some software to view your webcam feed. Ideally, the video should look along the lines of the image above (replace hand-draw face with yours :). If you aren’t getting good light, consider moving your desk setup, moving your light sources, etc. The diagram below gives a top-down view of what your setup should look like t this point.
At the time of writing (Spring 2020) probably the best free software you can use to get a greenscreen quickly up-and-running is OBS (Open Broadcast Software). Just go to the website, and download i+ install the appropriate version. I’m sure at some point in the future, these instructions will become outdated, but here’s the steps you need to follow to put the contents of your computer screen behind you! When you first open it up, it will take you through some initialization steps. After going through those, the window should show the main OBS interface.
Click the “+” button in the scenes area to add a new scene, then name it “greenscreen.” After setting that up, you’re welcome to delete the default “scene.” Next, in the sources section, click the “+” button to add our webcam video source. Press “+”, then “Video Capture Device”, then “Create New”. This will bring up a window to configure the video capture device. Your computer’s webcam should be an option in the dropdown. If it isn’t, make sure it’s plugged in and properly configured before proceeding.
After configuring everything as desired, click OK. Back in the main OBS menu, you should be able to see the video feed from the webcam! At this point, you should be able to resize the webcam source so be smaller, so that it it only covers the lower-left or lower-right corner of the screen, as shown.
Next, we need a second video feed to act as the background. For this article, I’m going to stick with capture a computer or tablet screen for the background, since the focus is for presenters / vloggers / streamers. However, keep in mind throughout all of this, it can be done with other video and still-image sources too. Press “+” in the sources area, then “Display Capture”, then “Create New”. This will bring up a window to choose which screen to capture. At this menu, you can either capture the contents of the computers main screen, the screen of a secondary monitor, or even the screen of an attached tablet, such as an iPad. For this example, I’ll be using an iPad. After adding this video feed and saving, you should be able to see it in the main OBS video preview.
However, doing this step might have placed the screen capture on-top-of the greenscreen feed. You can drag and drop the sources in the source list - so make sure that the camera feed is above the display capture source.
The last step is to replace the green pixels with the background! In order to do this, you’ll have to add a chroma-key filter to the webcam source. You might need to tweak the sliders to get it looking good for your particular greenscreen color, lighting, etc. With that, you should be ready to go!
The “studio” configuration I discussed earlier was a bare-bones, affordable-as-possible kind of setup. If you are willing and able to spend some $$$, and you have a larger workspace, you can arrive at higher-quality video, audio, and much improved lighting. In this section, I’m going to cover a more expensive setup (on the order or $1k - $2k, assuming that you already own, or have access to, both a laptop and desktop), but keep in mind that this is not an all-or-nothing decision. You can mix and match some of the more expensive components with some of the cheaper setups to get something that fits your budget.
This time, I’ll start off by showing you the setup diagram, and then go through each of the components.
In terms of the actual greenscreen, the options are the same as what I mentioned earlier. There are some cheap options, and some more costly ones.
The main differences are in the audio, camera, and lighting configuration. Instead of using a cheap or built in webcam, this setup involved buying a separate, high-quality camera for capturing the video feed. This can be done at a number of different budget levels, but the key component is that you need a video camera with: good quality video, HDMI out, audio in.
In 2020, a good/affordable option for this is the Panasonic GH4, which can be picked up body-only for $600. I’m sure 5 years from now, there will be a better option at that price point. You’ll also need to pick up a lens (can be done for around $250). In order to capture this video feed into a computer, you will need a HDMI/USB capture card. There are multiple companies that make these, such as Elgato, Razer, and Blackmagick. These can be picked up for $100-$200 each. Once you have the camera set up, connect the camera to the capture card (HDMI), and then the capture card to the desktop (USB). If set up correctly, this sill allow you to grab the video feed via OBS, using similar steps to what I explained earlier. This portion of the setup (camera, lens, card, cables, tripod) can be done for a wide variety of price points. You can get the GH4, suitable lens, Razer capture card, and the cables for around $1000.
If you’re going to start investing more money into your setup, one of the first things to invest in should be a lighting kit. If you’re ever tried greenscreening before, you’re probably aware that having bright and consistent light, as well as minimizing shadows, is very important for achieving a good result. A good starting point is to get three lights, one on each side of the subject lighting the sides of the subject and the greenscreen itself, and a third key light (or subject light) whose primary job it is to keep the subjects face and body well lit. There are a bunch of video lighting starter kits available online that include lights, stands, cables, etc, ranging in price from $100-$500, depending on the features you want. You might want to consider investing in LEDs to reduce both the heat and your energy bill. Once you get these, set them up as the diagram shows. You can also put your key light above the camera, so have more of a “straight-on” lighting look.
If you want to capture the contents of a computer screen to put in the background (whether for presenting or gaming), this setup is designed for a dedicated presenter computer. This could be a laptop, or even a tablet. You’ll need a second capture card to grab the contents of the screen on the desktop computer. Run an HDMI cable from the laptop to capture card, then a USB from the card to the desktop. Use the OBS steps shown earlier to overlay yourself (though the GH4 input feed) above the contents of the screen (a separate video feed in OBS).
Lastly, I’ll mention audio. It is perfectly acceptable to just use the built-in audio that comes from the camera. However, this can be problematic if you as the presenter plan to move around, or turn around where you aren’t facing the camera directly. My suggestions to solve this problem would be to spend $200 or so on an affordable lapel mic setup. Again, in 2020, my recommendation for a good bang-for-buck would be the RODE wireless GO mic system.
I have personally used a setup rather similar to this (though with a few more lights), and have been able to achieve a very high-quality, professional look.
I’ve gone over two possible setups in this article, but I want to make it clear that, really, there’s an option for basically every budget. For instance, you could follow the budget build, but invest an extra hundred or two on a light kit. You could also spend far more then even my “expensive” suggestions and invest in higher-quality equipment, a 4k camera, professional-quality lapel mic, and more. It boils down to you determine what you need, and what you’re willing to spend, but in the end, greenscreening can be done with any budget.