Adjusting Video Speed and Duration
You know you love it! What am I talking about? Slow motion. Picture this dramatic scene: A bride slowly turns to face the audience with a huge smile on her face. Hand in hand with her new husband as they walk out the door of the church, confetti falls, hands are clapping, radiant smiles are everywhere, and soft music plays. There is something about slowing down the action of such a scene that just completes it.
The drama that comes with slow motion isn’t just related to romance. If you’ve ever seen sports in slow motion, you know that it allows you to see everything that happens and really appreciate the skills of the athletes. Any way you want to look at it, changing the speed of video has a way of connecting with your viewers in an emotional way.
For the best possible slow motion, set your camera to start shooting at a higher frame rate and then slow it down to the equivalent of a normal 24 or 30 fps when you are editing in Photoshop. For example, some cameras allow you to shoot at a speed of 60 fps.
When you play back a 60 fps video at the usual 30 fps, you’ll have perfect quality video at 50 percent of the normal speed. Editing the speed also changes the duration of the action (60/30 = 2 seconds of footage for every second of captured footage).
Fortunately, even if you don’t possess a camera capable of shooting at 60 or 120 fps, you can still create great slow motion. Photoshop does an excellent job of interpolating the frames and playing back the video at different speeds with decent quality.
Slowing down the video action using Photoshop
Let’s continue with the project you’ve been working on (ch4.psd) and slow down the scene of the basketball players to 50 percent speed. Half speed may not sound like a lot, but you’ll be surprised by the effect that it has.
- Scrub the playhead until you see the basketball clip. Choose the desired basketball action clip by clicking on it in the Timeline.
- Right-click to display a Settings dialog with two options: Duration and Speed (Figure 4.10).
Figure 4.10. The Duration and Speed options in the Timeline.
- You want slow motion, so change the settings for speed to 50 and type in 14 for the duration (Figure 4.11). See the sidebar to understand why we changed the duration.
Figure 4.11. Changing the Duration and Speed options in the Timeline.
- Play back the video. It looks great in slow motion. If you need to further adjust the duration, click on the edge of the clip at the beginning or end and drag to change it. Notice that there is no sound now. When you change the duration of a clip, you lose the audio. You’ll fix the audio by masking it in Chapter 5, “Bringing Video Alive With Sound.”
- The transitions might also have been affected by the speed changes. Right-click on each transition to check its speed. The first one changed to .5 seconds, as you can see in Figure 4.12, and the second one changed to 4 seconds. Right-click and type in 2 seconds for each one. If the speed of your transitions didn’t change, great!
Figure 4.12. Fixing the transition speed.
- Play back the video again just to make sure it plays the way you want it to (Figure 4.13).
Figure 4.13. Playing back the video to check the speed and transitions.