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After Effects Tutorials / Video Editing

How to Speed Up or Slow Down a Clip in After Effects

speed ramping after effects

One of the most-used and simple-to-use options inside After Effects is to speed up or slow down a clip to achieve our desired outcome. However, it might be simple to use, but if not used right, it might create still frames and the image will not run smoothly or you will get a “Quality Check Failed” status if you plan to upload to TV Stations.

Adobe After Effects is my favorite post-production software out there. I can create almost anything with it. This is how an old saying got born at the studio I used to work in: “Anything is possible! We just need time and money.”

In this article, I will cover the ways you can speed up or slow down a clip in After Effects and the pros and cons of each method.

To simply speed up or slow down in After Effects is super easy. Just right click on your clip > Go to “Time” > “Time Stretch”, then change you percentage to the desired speed. That’s it!

Method 1: Speed Up or Slow Down a Clip in After Effects With Time Remap

To speed up or slow down a clip in After Effects with Time Remap, you don’t have to go through many steps and it is easy to understand the process behind it. What does it do? With help from keyframes, it compresses or expands all the keyframes of the video clip you want to be modified.

Ok, let’s do it!

1. Enable Time Remapping

Right-click the video clip or pre-composition, go to “Time and select Enable Time Remapping”. A new parameter will appear in the layer options and its name is “Time Remap”. 

after effects time enable time remapping

2. Adjust the keyframes

There will be a keyframe at the start and the end of the video or pre-composition. Consider the space between the two keyframes as the entire length of your footage. By simply dragging the end keyframe closer to the start keyframe, you will speed up the video. However, if you drag the keyframe further away from the starting keyframes, you will slow down the video.

keyframes in after effects

3. Add a smooth speed ramp using the keyframes and easy-ease

Easy ease can be applied to the keyframes; this will work as it should. You can also speed up or slow down parts of the video by isolating the desired part with two more keyframes and then.

For example, move both the keyframes at the end of the desired part and the keyframe at the end of the video to the right and the video will slow down. You can also move the ones at the start, it will still work, but you will speed it up.

adjusting the keyframes with time remap

4. Remove Still Duplicate Frames

The downfall of this method is when you want to slow down a video, Time Remap will create still frames. But don’t worry, there is a solution to this problem.

A still frame is a duplicate, consecutive frame usually created by the editing software when the framerate of a video is changed or a slow-down effect is applied, without any frame blending software. When in play, an untrained eye will miss it, but for an expert, it will feel like the flow of the video “skips a beat”.

To avoid still frames created from slowing down the footage, you have to enable the layers Frame Blending check-box after you activated the composition’s Frame Blending icon. This option will analyse all your frames and will create/adjust new intermediate frames, therefore, everything will play smoothly. You will not have to explain to the client why the image stutters. Click it once for normal frame blending and click it twice to allow AE to digitally create new intermediate frames.

Method 2: Advanced Speed Ramping Inside After Effects

This technique is more advanced than anything else in this article — you first have to understand Time Remap. Speed ramping is used when you want to have better control over how the speed of the time breaks or accelerates. For example, if you want to start really slow, then steady accelerate, follow with quick acceleration and finally decelerate in a mirror-way as you started.

1. Set keyframes for Time Remap, activate Frame Blending and open the Graph Editor

After you set the keyframes for the Time Remap parameter and make sure the Frame Blending option is active, select a keyframe and press on the Graph Editor.

graph editor in after effects
Speed ramping inside After Effects

2. Edit Speed Graph and set the first keyframes

From the bottom of the screen, you will want to change the graph type and make sure it is set to “Edit Speed Graph”, by default, it will show us the Value Graph. Moreover, go back to normal view by clicking again on the Graph Editor, set the first keyframe to “Easy Ease Out” and the last to “Easy Ease In”.

2. Use the yellow handlebars to add a gradient of speed

Press again on the Graph Editor and drag the yellow handlebars how you see fit. I’ll give you an example below:

add speed ramp

This is how it looks

This is how it looks in play before and after:

Before

After

Method 3: Speed Up or Slow Down a Clip in After Effects With Time Stretch

Time Stretch is the easiest way to speed up or slow down a clip in After Effects. With just a few clicks, you can finish your job. There is a downfall if you want to slow down clips, it will make still frames, but you can get rid of them by using Frame Blending. In addition, you can only apply it to the whole clip and cut the layer afterward.

1. Go to “Time” > “Time Stretch”

To use it, right-click the layer, go to “Time”, and select “Time Stretch”. A new window will appear here, and just like in Premiere Pro you can select the percentage you want. The only difference is that there is no optical flow or any frame blending option.

Time Stretch in After Effects

Type in the percentage you want and press OK. Whatever value over 100 will slow down the clip, whereas any value under 100 will speed up the clip. This is also different from Premiere Pro’s speed option, where it’s exactly the opposite.

If you want to know more differences between After Effects and Premiere Pro, you can read about them here.

Summary

To summarise, by following these steps, you will know for sure how to speed up or slow down a clip in After Effects. Furthermore, using the Speed Ramping method, you will be able to control the acceleration or deceleration of the time speed. I recommend using Time Remapping all the time unless you just need a quick adjustment and nothing more serious.

About Author

After spending 6 years in the post-production studio, Mihai decided to share his insights on video editing and computers.

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