Adobe After Effects techniques lead to convincing green-screen special effects

Beginners learning the basics of creating special effects might be daunted at first by the complexity of modern software, but with a bit of planning and practice, you’ll be making scenes akin in quality to Star Trek’s original series in no time.

As a first-year student in Humber College’s multimedia design and production technician program, it is essential to have an understanding of how to use most of the applications in the Adobe Creative Suite. Learning each program can have its own growing pains. Especially in the case of learning how to edit videos through Adobe After Effects. As a beginner, if you’ve had no experience applying special effects to raw footage, the technical and creative endeavors can be daunting.

My assignment from my program at Humber College was to produce a short video making use of green screen special effects. Green screens allow actors to stand in front of a green canvas and have a background superimposed in the editing process.

Working with a group, we chose to make a B-movie style, sci-fi clip titled “The Chin from Planet X.” The premise being we would shoot a person’s chin upside down, attach googly eyes to it, and make it look like a space monster attempting to eat some stranded astronauts. After spending some time on a set jumping around in costume, we had raw video assets, but still had the task of plowing through the post production.

While in the program, you have to understand the subtleties of each effect you’re working with. First a “key light” filter has to be applied, eliminating any green and leaving a transparent matte in its place. The filter must be modified further to eliminate remaining green from spilling over into the scene, and reducing graininess. A user has to adjust the gain, change the tolerance on the levels for black and white, and further edit masks and feather edges.

On first impressions the layout of After Effects seems like many other Adobe apps. Like in Photoshop or Premier, you work with videos and images on different layers and timelines. You rearrange the clips and assets as necessary, and eventually you have your footage organized into a neat composition. Once you’ve settled on your arrangement, you have to move on to experimenting with the special effects.

Learning some After Effects techniques can lead to convincing special effects.

This is where things get tricky. After Effects has a way of being able to “create something from nothing,” in that some impressive visual effects can be done with a click of a button. By previewing some of the presets in Adobe Bridge, you can do anything from animating text to applying motion blur to a moving object.

The user also has the option of mixing and matching different elements together. By combining different generators and filters, an editor can stumble upon an entirely original effect. A user will find that they have to develop a certain knack, in that they have to adjust several different sliders and apply key frames just right. Without adjusting the effects to preference, the illusions aren’t as believable.

Finally, once the composition is finished the user still has the problem of actually exporting the video. On first use, I found After Effects strange, as the only export option was SWF, a Flash-specific format (by going to File >Export). I learned quickly that to get a conventional video format you have to export by going to the Composition Tab and adding the whole project to a render queue. These are just but a couple of the tribulations faced when settling on standards used in the output module.

It isn’t as simple as simply choosing a destination for your project to be saved to, as there are literally dozens of video formats and codecs to choose from. First, know what screen-size and aspect ratio you’ve been working with, and how detailed the resolution should be. Then select a codec that will compress the video to a reasonable file size. Often I would go with Apple ProRes 422 (HQ) under the advice of my professor.
Unfortunately many first time users don’t clue into this and blindly hit the render button, only to find that less than 30 seconds of video could end up becoming a 4 gigabyte file. This is due to the default codec setting, which is known as animation. This exports it with lossless compression, meaning every frame of the composition is processed to fine detail.

Having worked through all of these obstacles, I’m starting to understand how to work with After Effects a little more intuitively. Though the hurdles of resolving the technical issues is frustrating, there is a pay off and gratification in being able to resolve them. Now that my cheesy sci-fi short is up on Youtube, I find a lot of satisfaction in seeing others’ reactions to something I’ve put a lot of work into.

And since I’ll never really be able to explore alien worlds, this is the next best thing.

Brent Jackson is graduated from Humber College’s paralegal studies program, and is now taking its multimedia design and production technician course.

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