Achieving a good green screen effect used to be difficult and expensive. But no longer. In this post, I’ll show you how to make your first green screen video on the cheap. We’ll take a look at the various elements you need to consider: backdrop, software, camera, lighting…and how you can probably pull off your first green screen production for $30 or less.
Before we get started on the how…let’s talk about the why. Why would you ever want to use a green screen effect in your video? To what end?
What is green screen and why would I use it?
Green screen is when you replace the real background of a video with a digital background.
Quite simply, it offers the most natural-looking way to integrate a human with other types of content you might want to show, such as presentation slides, screen video, screenshots, photos, or animated elements. Instead of putting each visual element in its own frame (a la picture-in-picture), green screen lets you blend them seamlessly.
What gear do I really need?
Backdrop (usually required)
To get started today, you just need a regular digital camera (or smartphone) that shoots video, some inexpensive software, and a wall that’s painted a color that does not appear anywhere on your clothing, skin, eyes, or hair. Since walls like that are sometimes hard to find, you should probably plan on buying a piece of muslin cloth that’s a hideous shade of green. Something like this:
Software (required)
For software, of course we’re biased toward Camtasia for Mac, which you can download and use free for 30 days (it’s $99 to buy). The benefit of using Camtasia is that you can easily add screen captures and other media to your project.
Camera (required)
For a camera, you want something that shoots HD quality video (720p or higher) and that saves out files in a format your green screen software can import. Camtasia for Mac can import most MP4 and MOV files; we’ve had good success just using an iPhone but most any digital camcorder that generates either of those file types should work.
Pro screencaster Scott Skibell posted a screen test, comparing the results of four different cameras: iMac iSight built-in webcam, Logitech C910 external webcam, iPhone 4S, and Canon T3i. To really see the detail, click through on the video and watch in HD in the large player.
Not seeing the video? Watch it on YouTube…
Lighting (optional)
The remove a color effect in Camtasia for Mac is really quite forgiving of background shadows. Spend a few minutes tweaking the settings a bit and you should be good. But if you’re having trouble getting the background to fully disappear or there’s a slight halo around the person, it means you need to upgrade your lighting. The more even your lighting, the better the effect will be.
The easiest thing to try is a couple of hardware store clamp-on work lights with high-output CFL bulbs…and something to clamp them on. Aim the lights so that the green screen doesn’t have dark areas and bright areas. Focus your efforts on the area directly behind the person, as you’ll be able to crop out the excess space around the person later (don’t forget to factor in the person’s “gesture zone”).
To really throw a lot of light, you need multiple bulbs in each fixture. You could build your own video lighting rig for less than $100 (see video below). Or if you’re not into DIY projects, you can shop around for a video softbox. CowboyStudio is a good place to start. Look for “continuous lighting”–as opposed to flash or strobe lighting. Whether you buy or build, it’s best to use a diffusion filter for each light, as that will help keep them from throwing shadows.
In this video, the folks at Indy Mogul not only show how to build your own lighting kit on the cheap…but give a quick demonstration of the how and why of 3-point lighting.
Not seeing the video? Watch it on YouTube…
C’mon, is it really that easy?
Yes, yes it is. To convince internal TechSmith staff of how easy it is to make greenscreen video, Camtasia product manager Shane Lovellette made a quick demo showing off some ways to use the effect…and then pulls back the curtain on his not-so-super-high-tech setup. 
It really is that easy and inexpensive!
Not seeing the video? Watch it on Screencast.com…
UPDATE 7/19 – from Shane Lovellette
One more tip that might help your results is to try adding a Spotlight Video FX to your clip after you have applied and tweaked Remove a Color. With Spotlight, you can choose a color for the spotlight. Select a color such as red or a warm skin color. Then adjust the opacity. It will help warm up the subject, and tends to help hide some of the green fringe you may get at times when the lighting isn’t perfect. The key is to add the spotlight after remove a color.
So go ahead…put yourself in your video, see how your audience receives it, and share your story with us! We’d love to show off some great examples of chroma key video!