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Green screen tutorial

In this tutorial, we’ll be showing you how the basics of keying out a green screen background footage using Adobe After Effects. The techniques used here require no plugins, and serve as a great starting point if you’re just starting out working with green screen. 

Step by step

1 – Once your footage is in the project, right click the file and select Create New Comp From Selection. This will automatically take your footage and create a new composition with the correct video settings for your clip.

2 – Firstly, head over to the Effects and Presets tab, and in the search bar, type in: Keylight. What you want to select is the combined effect named Keylight, Key Cleaner and Advanced Spill Suppressor. Drag this effect over your footage.

3 – Now that you’ve applied the basic keying effects, navigate to your Effects Control panel, and click on the eye dropper tool. You’ll want to select an area of the background close to the figure, but not any shadows or bright spots.

4 – Instantly, you should see some changes take effect. Depending on the lighting of the green screen footage, it could look really clean at this stage, or a bit messy. Either way, there are further adjustments we can make to clean up the key. 

5 – In Keylight, open the drop down menu in the View option, and select Screen Matte. This will reveal what the key is doing. The white parts are what is staying on screen, and the black is what is removed. If there is any grey or dark grey left, we will need to work with the screen matte settings to push them in the right direction.

6 – Open up the screen matte setting, and start by lowering the Clip White. This will ensure the subject stays in focus and is clearly cut out. Once you are happy with the selection, move down to Clip Black and increase its value until all of the dark grey or grey material disappears. 

7 – Once you are satisfied with the adjustments made in the screen matte, head back to the view option and set it back to Intermediate Result.

8 – At this point, there may still be a bit of green around the edges of your subject. If there is, the easiest fix would be to return to your Effects Control panel and turn on Advanced Spill Suppressor. 

9 – Now you should have a working key! There are a wide variety of issues that you may run into when working with green screen footage, but this tutorial should help you get started with creating a working key.

If you have any questions about the techniques employed here, or if there is an effect you would like us to create a tutorial on next, let us know over on the YouTube comment section.