Published: July 6, 2020 | Last Updated: September 16, 2024
Since it’s paramount that you record your footage at a certain frame rate for the type of slow-motion look you want, you need to make sure you get it right on set. For a recap on how to shoot slow-motion footage, check out our Beginner’s Guide to Slow-Motion Footage.
Setting the Frame Rate
The trick to editing slow-motion footage is all about the frame rate. When you intentionally shoot slow-motion footage, you try to shoot it at a higher frame rate than the one your video will play back.
The most common frame rates are 24 fps and 29.97 fps, which rounds up to 30 fps. You will want to shoot at an FPS that’s at least double the frame rate you are shooting at.
In general, the higher the frame rate, the “slower” you can edit your footage to be.
For example, if you shoot something at 96 fps, your footage will be 4x as slow when played back at 24 frames per second, allowing you to play your footage back at 25% of normal speed.
Here’s a graph that breaks it down based on 24 fps timelines and 29.97 (or 30) fps timelines:
| Recording Frame Rate | Timeline Frame Rate | % of Normal Speed |
|---|---|---|
| 24 | 24 | 100.00% |
| 30 | 24 | 80.00% |
| 50 | 24 | 48.00% |
| 60 | 24 | 40.00% |
| 96 | 24 | 25.00% |
| 120 | 24 | 20.00% |
| 200 | 24 | 12.00% |
| 240 | 24 | 10.00% |
| 300 | 24 | 8.00% |
| 960 | 24 | 2.50% |
| 1000 | 24 | 2.40% |
| 24 | 30 | 125.00% |
| 30 | 30 | 100.00% |
| 50 | 30 | 60.00% |
| 60 | 30 | 50.00% |
| 96 | 30 | 31.25% |
| 120 | 30 | 25.00% |
| 200 | 30 | 15.00% |
| 240 | 30 | 12.50% |
| 300 | 30 | 10.00% |
| 960 | 30 | 3.13% |
| 1000 | 30 | 3.00% |
As you can see, if you record at a starting frame rate of nearly 1000 using an ultra-slow-motion camera like the Sony RX100 VII (which can shoot at a whopping 960 fps!!), you would be able to play back your slow-motion footage at a speed of 2.4-3% of what you shot it at—which is ultra-slow motion!
How to slow down your frame rate in playback.
Now, let’s get specific about how to edit slow motion depending on your editing software. The three main editing software programs we recommend are Adobe Premiere, Davinci Resolve, and Final Cut Pro.
So, let’s go through these three and learn how to slow down your footage for each.
How to Edit Slow-Motion Footage on Adobe Premiere.
For an easy-to-follow tutorial on editing slow-motion footage on Adobe Premiere Pro, we like this video from the YouTube channel Think Media by YouTuber Sean Cannell (jump directly to 9:08 to get right into the editing tutorial):
Here’s a recap:
- Start a new project with the appropriate settings; to edit slow-motion footage, you’ll want to set the base frame rate at 30 (really 29.97) frames per second (fps).
- Import the clip you want to make in slow motion. Ideally, it should have a higher fps than 30. Once imported, click on the clip and select Modify > Interpret Footage.
- In the Interpret Footage window, check the option “Assume this Frame Rate” and set the frame rate to 29.97.
- Now drag the clip onto your timeline and delete the audio (to save your ears the garbley wub wub of slowed down audio), and you’ll see the footage now in slow motion as you play it back!
There you have it. That is the most basic way to create slow-motion footage in Adobe Premiere Pro.
How to Edit Slow Motion Footage in Davinci Resolve.
For editing slow motion footage in Davinci Resolve, I found this video created by Youtuber JayAreTV to be very simple and easy to follow. Check it out below and see underneath for my step-by-step recap:
Here’s a recap:
- Start a new project with the appropriate settings; to edit slow-motion footage, you’ll want to set the base frame rate at 30 (really 29.97) frames per second (fps).
- Import the clip you want to make in slow motion. Ideally, it should have a higher fps than 30. Once you drag the footage onto your timeline, click on the clip you want to slow down and choose Change Clip Speed.
- In the Change Clip Speed window, you can now change the speed percentage (depending on what frame rate you shot at—see the chart above for the optimal speed for your clip’s frame rate).
- Make sure you check the option to Ripple Sequence. This means that once your clip is extended, the rest of the sequence will move with it, so the clip doesn’t overlay any other footage on your timeline.
If you keep watching the video, you’ll see a few more ways to edit the speed of your footage, but the above are the most basic steps to change your clip to slow motion in Davinci Resolve.
How to Edit Slow-Motion Footage in Final Cut Pro.
Here’s another tutorial on how to edit slow motion in Final Cut Pro. This video is from YouTuber OmarOmarOmar, who gives a quick and breezy recap on how to set up and edit a slow-motion clip in Final Cut:
Here’s a recap:
- Start a new project with the appropriate settings. Set the base frame rate at 23.98 or 24 fps, but you can do up to 30 fps.
- Drag the clip onto your timeline.
- Go to your clip in the player and click the stopwatch icon underneath the footage.
- From there, select the option Slow. You will then pick a percentage from the list between 50% – 25%. Make sure you pick an option based on the chart above. Anything more than 50%, you start to push the footage into choppy territory.
- On the clip in the timeline, you can edit the speed in more detail by clicking on the arrow dropdown next to the percentage overlay that is now on your clip since you slowed it down.
And that’s the essentials for slowing down a clip in Final Cut Pro.
How to make slow-motion footage look smooth.
If you’ve been following along, you’ll know that the best way to create smooth slow-motion footage is to record it at the highest frame rate possible.
However, shooting at a super high frame rate isn’t always an option, especially if you are using a camera that doesn’t have superslow-motion capabilities. You can use a few tricks to smooth out your slow-motion footage, which we’ll cover below…
Optical Flow
Optical Flow helps transform regular footage into slow-motion footage by creating frames where there aren’t any.
For instance, if your footage is 30 fps, you can use Optical Flow to increase that footage to 60 fps without repeating the same frames every time (which is how it would work if you just doubled the frame rate without Optical Flow).
Frame Blending
Frame blending takes two frames and creates a third one, a blended combination of the two, to help smooth out the footage. However, this creates a less-than-ideal motion blur.
For a comparison of these two tools, check out this video comparison from Youtuber Brice Suazo:
Frame Sampling
Frame sampling is a trick that adjusts the number of frames to match the speed setting by either removing frames or repeating frames until the required speed is reached.
Here’s a video explaining each:
Applying Optical Flow, Frame Blending, and Frame Sampling.
Here’s how to use the above techniques depending on your editing software:
Adobe Premiere Pro.
All three of the above techniques (Optical Flow, Frame Blending, and Frame Sampling) are usable in Adobe Premiere Pro via a setting known as Time Interpolation.
To use them, simply select the settings option on your footage and choose the Time Interpolation option. Then, from the drop-down menu, select the tool you want to apply, whether Frame Blending, Frame Sampling, or Optical Flow.
Final Cut Pro.
Youtuber TAVA has a good tutorial that will help you apply these tricks in Final Cut Pro.
To recap in the briefest possible terms, once your clip is selected, go to the stopwatch icon and select the option called Video Quality. From there, you can apply either Frame Blending or Optical Flow to the clip.
Davinci Resolve.
Youtuber Digital Vector Studios put together a great tutorial on using time editing in Davinci Resolve. Check out the video below.
You can go to 2:20 for the section specifically on Optical Flow. Digital Vector Studios recommends you have the Inspector window up. From there, select the option Retime and Scaling, and under Retime Process, choose between Optical Flow or Frame Blend.
More about speed ramping.
In addition to traditional slow motion, there is another technique you can use to edit the speed of your clips called speed ramping.
Sometimes referred to as The Matrix effect, you can easily use speed ramping to move between fast and slow motion.
Check out our article here on how to use speed ramping.
Another method for creating slow motion: the Twixtor Plugin.
There is another technique that has become popular lately to create and edit slow motion footage. It’s done through a plug-in called Twixtor that uses a digital fabrication process that interpolates frames between the ones you shot to create more frames.
Here’s an example of Twixtor in action:
Created by RevisionFX, Twixtor is essentially a more advanced version of the frame blending technique mentioned above, as the plug-in analyzes and interoperates your footage to predict what the video should appear as in a slow motion environment, and can even add motion blur.
Through using Twixtor, you can slow down or speed up your footage, and even convert the frame rate of footage shot at 24 or 29.97 fps so that it matches whatever frame rate of slow motion you are looking to create.
Twixtor has a lot more flexibility and functionality than the native plugins, particularly because it is constantly being iterated on as a standalone product.
The native plugins, on the other hand, essentially do what they are asked to do with limited functionality because they are only one part of a larger product, and therefore can’t compete from a pure features perspective.
How to slow motion video online
There are many online-only options for converting a video clip into slow motion. These resources are not going to be as powerful or look as high quality as editing the slow motion directly from a professional editing software, but if you’re looking for a quick fix, you can always check out these options:
Keep in mind, each website has their own policies about what happens to content once you upload it to their website, so make sure to do your research before you throw anything up willy-nilly.
How do you slow down a timelapse video?
It depends on how you shot the time lapse. For example, if you shot the time lapse video with a smart phone, there are specific tools and apps you can use to slow it down.
In particular, if you shoot on iphone, you can download the iMovie app to your phone for a quick and easy editing process, or even try something like Hyperlapse or OSnap which are apps that were created specifically for editing and creating time lapse videos.
However, if you are creating a time lapse video with a professional film camera, the best option is to use a combination of Adobe Lightroom and LR-timelapse which is a professional tool.
Closing Thoughts
If you have more specific questions related to editing slow motion, let us know and we’ll update this article to reflect those specific questions.
Otherwise, take your time to research and watch the videos in question and you should be in pretty good shape for editing your own high-quality slow-motion videos!
