Slow-Mo and

Speed Ramps

A very popular effect is to slow down or speed up the timing of a shot. Most editing applications are very good at handling these sorts of effects. You can pick a speed, pick a duration, or set key frames for a variable speed shot, also known as a speed ramp. A classic speed ramp is a shot that starts out at normal speed and then gradually ramps up into ultra fast motion (see Figure 17.8)

Figure 17.8

Changing the speed of a clip in your editing application is easy.

True Slo-Mo

True slow motion footage is shot at a very high frame rate so that a great amount of detail in motion is preserved—think shot of a hummingbird where you can see each beat of its wings. Only a few special cameras can shoot high frame rate video, so if ultra-smooth slow motion video is important to you, you’ll have to shoot with the right camera to get it.

Integrating Still Images and Video

One of the most common effects is adding motion to still images. Using a basic “Resize” or “Motion” effect, you can pan across the image, zoom in, or reframe to create a dynamic sequence. Once upon a time, you actually had to reshoot the images with a video camera, a process called motion control, but happily those days are long gone, and you can do anything you need with the simple effects available in your editing application.

Here are a few basic tips when working with still images:

nUse the highest resolution images that your editing application can support. That way, you’ll have lots of room to zoom in without degrading the image quality (see Figure 17.9). Premiere, for example, can accept an image that is 10,000 8,000 pixels. That’s about five times bigger than the resolution of 1920 1080 HD video.

nIf your editing application doesn’t let you import still images that are larger than your current video resolution, and you need to zoom in or otherwise enlarge an image, use a dedicated motion graphics program like Adobe After Effects to create your moving still image shots.

nRemember that dissolving between static still images can also create a sense of motion.

nTry to choose images that will work well when framed to fit the aspect ratio of your video. Vertically-oriented photos can be hard to work with.

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Figure 17.9

Using a high-resolution source image means that you have lots of room to enlarge the still photograph when adding motion effects.

Special Effects Workflow

Before we start talking about manipulating the image, it’s important to consider some workflow issues. If you’re using the internal effects tools in your editing application, you won’t need to worry about workflow much, but if you are farming your compositing out to a visual effects specialist or to a dedicated special effects application such as Adobe After Effects, you’ll benefit by taking workflow into consideration.

Think about the following scenario: You’re editing a low-budget sci-fi epic about extraterrestrial book authors who invade Earth and begin boring everyone to death by reading detailed digital video specifications at them. You have a 45-second-long edited sequence of the Grand Canyon. At 10 seconds into this segment, you want to composite an animation of a flying saucer over the edited footage of the Grand Canyon. The saucer will take about 10 seconds to majestically descend into the Grand Canyon and will be out of sight by 20 seconds into the clip (see Figure 17.10).

Although you’re editing in Adobe Premiere, you plan on performing the composite of the spaceship using Adobe After Effects. Therefore, you’ll need to export footage from Premiere, import it into After Effects, perform the composite, and then bring the composited final footage back into Premiere.

Figure 17.10

With good storyboards, we can better determine which parts of a clip are required for an effect.

Although our Grand Canyon sequence in the preceding example lasts 45 seconds, the section where the spaceship will be seen is only 10 seconds long. Therefore, rather than move the whole 45 seconds into our compositing program, it’s better to move only the 10 seconds that matter. In general, most effects shots are very short—a couple of seconds here, a few frames there—so you’ll be able to get away with moving very short clips between your effects and editing packages.

In the preceding example, our compositing work will proceed as follows:

1.First, we will find the 10 seconds of footage that we need for our composite.

2.This footage will be marked for output. In most editing programs, you do this by setting special inand out-points in your timeline that denote which section of a sequence will be rendered and output.

3.Next, we will output the selected video. In our output settings, we’ll select the QuickTime Animation codec as our compressor. The Animation codec is lossless, but creates substantially larger files than most other codecs (see Figure 17.11).

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Figure 17.11

No matter what application you’re exporting video from, at some point you will be given a choice of which QuickTime codec to use for compression. When moving between applications, use a lossless codec such as Animation.

4.The resulting 10-second clip will be imported into After Effects. There, we will perform our composite.

5.In After Effects, we’ll render our finished composite. Again, we’ll choose the Animation codec when saving, to ensure the highest quality.

6.Now, we’ll import the new, composited, animation-compressed clip into Premiere and edit it into our sequence, replacing the footage that was there before. When we create our final output, this new clip will be compressed with the same codec as the rest of our footage.

In the interest of staying organized, when naming new files—such as composites and other effect clips—use the same naming conventions that you used when you digitized your footage, and be sure to back up the new files on a hard drive.

Moving Media

When moving files between apps, you’ll also want to be sure that you always use the same frame size and frame rate. Note that some applications will default to 30fps rather than 29.97. The only time you should render to a different size or time base is when you are intentionally trying to shrink your movie for output to the Web or other low-bandwidth medium.