Another type of clip retiming that you might encounter is slow motion. This is when footage is shot at a higher frame rate so that the footage can be slowed down in postproduction. In this movie, author Richard Harrington walks you through how to create a slow motion clip with Adobe Premiere Pro and Adobe After Effects.
- Besides the ability to do frame-rate conversions, After Effects can also be quite helpful for advanced motion effects. If you'd like to really slow down footage, this advanced frame blending can really come in handy. Plus with variable-speed timer mapping, it can be quite useful. In Premiere, let's open up the sequence here called Run. In here we have a 60-frames-per-second clip of a runner. This is more frames than we actually need.
What I'm going to do here is change the sequence settings to 24. And click OK or Return. Now initially Premiere is going to keep the footage as is, and that's fine, but you can reveal this in the project if you'd like, and assign a new frame rate. In this case I can right-click on the clip and go to Modify, Interpret Footage. And I can assume a frame rate of 23.976 and press Enter or Return.
Now the clip is longer and the frame rate actually matches the sequence. You'll notice that the overcranked footage is going to play back in slow motion. But we can still slow this down even more. Let's right-click and Replace With an After Effects Composition. It's handed off into After Effects as so. Now I'm going to go into the Composition Settings and triple the duration. So let's take this to about 90 seconds.
And click OK. You'll notice that the footage needs to get quite a bit longer. If I right-click here on Columns, I can choose Stretch. And I'm going to stretch this 300%. I recommend sticking with a constant rate if possible. Now we'll turn on global frame blending and enable it in the Advanced Mode. Let's do this at half quality here, and we'll invoke the preview.
What you see is a very nice slow motion effect. And After Effects is dealing with the panning camera and the moving subject, combining both the overcranked footage where we shot at a higher frame rate than we needed for delivery. And the ability of After Effects to slow things down with advanced frame blending, we've got a very slow-motion effect here. It's working quite well. Let's pause for a second and Save. And if I switch back to Premiere and set this to half-quality playback to match After Effects, you'll notice that we get real-time performance initially.
All of the cache frames are handed off. Eventually you'll run out of those cache frames and it will start to drop them. But what's happening in the background is it's starting to build out the frames and it will hand those off. There it is. Remember, it got confused after we did the Replace here. But select it, and we'll choose Edit Original, it opens up, I'll hit Save and switch back, and now it's updated and knows that there's more frames available.
Now this is a little bit tricky, but it's because Premiere didn't know that you changed the duration. But by invoking the Edit Original command, it forced it to hand it off to After Effects and then sent it back. The initial frames that are already cached will play back in real time. But once it gets to frames that have not yet been cached, we'll start to see dropped frames during playback. That's okay, as it continues to play, more frames will become cached and it will eventually play in real time.
You'll note, too, that if you switch back to After Effects, since it's been playing in the background, it's starting to cache frames. Let's just set this to half quality and I can see that some of the frames are already loaded. As we play in Premiere, let's go to the 45-second mark here, you'll see eventually frames drop. There's the yellow. But when we switch back to Affect Effects, the frames that it received were properly cached.
This makes it easy to switch between the two programs. Remember, matching your playback quality in both programs will make it easier to hand preview files back and forth. Whether you want to take advantage of advanced slow-motion effects here with frame blending and morphing, or you just want to do the Edit Original command, there's a great hand-off here. Remember, if you do something dramatic like change the duration of the After Effects comp, be sure to reinvoke the Edit Original command from Premiere Pro, to force it to update.
- What's Adobe Dynamic Link?
- Creating and importing After Effects compositions
- Using Render and Replace
- Editing clips and sequences in Audition
- Creating and importing Photoshop files
- Editing Premiere Pro footage in Photoshop
- Sending clips and metadata from Prelude to Premiere Pro
- Working with slow motion
- Creating merged clips and subclips