Friday, July 2, 2021

Advanced Green Screen Techniques

Many Twitch streamers opt for green screens to spice up the look of their content. This tool allows a broadcaster to cut themselves from the background and insert themselves into any scene they choose. They can appear above (or within) the game they’re playing, and they can create all sorts of interesting shots for other moments of the broadcast. I already helped you to set up and troubleshoot basic green screen features in the entry Using a Green Screen for Streaming, but there are of course unlimited directions you could go with such a tool. This time, I’ll help you to solve some more complicated issues, and hopefully inspire you to go further outside the box with your green screen ideas. Let’s go over a few advanced green screen techniques. 


First, it’s important to make sure that parts of you aren’t being cut off in your camera shot. In past entries, I’ve spoken about the importance of composition within the frame of an image. With green screens, this topic is just as necessary, but in a different way. When you key yourself out of a background, you no longer need to make sure the shot within your camera is a good composition, because you can move the keyed image however you want in your streaming software. The important aspect of placing your camera, when it comes to green screens, is to ensure that you’re capturing everything you want to see, in its entirety. This parameter will of course be different for every streamer. If you’re sitting at a desk, the camera is probably able to see your head, shoulders and maybe a little bit of your chest. When you're using a normal (non-green screened) camera shot, it doesn’t look that strange if the top of your head goes past the top of the frame, but when you’re keyed out from a green screen, this is suddenly very noticeable. There’s no longer any natural border for the viewer to see in your camera shot, so you’ll simply look like you’re missing a chunk from the top of your head. For this reason, you might want to either zoom your camera out, move the camera further back, or adjust the crop you’ve created in-software, to capture your entire head. 

This looks good here, but if he was in front of
a green screen, his left and right arms would
be cut off.

You also want to keep in mind the places you might move to. For many of us, streaming isn’t a completely stationary activity. You might shift left or right in your chair, you might swing your arms, or you might even be getting up and dancing your heart out. It’s worthwhile to experiment by moving around and seeing whether you’re being cut off by the green screen. This will depend on what kind of shot you’re going for. If you’re sitting at a desk, maybe make sure that you won’t be cut off if you accidentally shift to the other side of your chair. If you’re capturing a zoomed out shot of your entire body while playing VR, then see how far to the left and right you’re able to move without leaving the shot. These are instances where watching your stream after the fact can be helpful as well. Were there any unexpected places where your green screen cut you off? Of course, you’re not filming a movie- the point of a streaming green screen is not to completely trick the viewer into thinking you’re somewhere else- but making sure you’re not hitting the edges of the key wherever possible will certainly help to make your stream look more professional. 

One other technical issue to watch out for is unwanted blurring. Your streaming software is looking for a hard edge between yourself and the green background, so it can cut you out. If your camera goes out of focus, that edge will become fuzzy, and it will ruin the look of your key. There are various reasons a camera might go out of focus, and when setting up a green screen it could be useful to return to the entry I wrote on this topic, called Focusing a Streaming Webcam. Blurring can also be caused by insufficient lighting, and you can find more info about how to get better lighting for your stream (even just by using household items) in the entry How to Make Your Camera Look Better


Snake is always the designated driver.

There is, of course, a lot you can do with a green screen. It’s most common to simply project the streamer in front of the game they’re playing, but there are plenty of other uses for this tool, especially when you’re taking a break from your game. You can make it look like you’re sitting within the environment of your favorite movies, anime, games, and all sorts of other things, while you talk to chat for example. I’ve seen streamers do fun things with layers on their green screens as well. With creative use of a background behind them and a foreground element in front, I’ve seen streamers make it look as if they’re sitting behind news desks, inside spaceship cockpits, and other fun scenes. 

Using layers in front of you as well as behind can create much more interesting effects for your scene that you can’t do by simply cropping your shot in-software. If you wanted to make it look like you’re in a wild west jail cell for example, simply finding an image of prison bars with transparency would allow your body to appear behind each blank space between the bars. You can place video smoke effects in front of yourself on a cyberpunk street to add more atmosphere, or have a car dashboard in front, with a moving background behind to create the effect of driving around. Try to think outside the box with your ideas, and you might just stumble upon a whole new signature look for your channel! 


Whether you’re solving issues with your green screen or coming up with new creative concepts, the most important thing is to take your time. Don’t try to make big fixes or changes right before going live- give yourself a nice open-ended chunk of time to really put your mind to the challenge. There’s a whole world of possibilities out there, as long as you’re willing to look for it. So give some of these advanced green screen techniques a shot. 

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