After Effects Time Stretch feature allows you to slow down or speed up your video in case you want to create slow motion scenes or high speed time lapse respectively.
This feature is very easy to use, and results can be seen just by changing a few values. Now, If you wish to create slow motion shots, then your RAW footage must be shot at 60 frames per second or FPS.
The basic frame rate, which we use are 24, 25 as well as 30 FPS and creating slow motion with these frame rates will not give you satisfactory results. But, now a days, advance and professional D-SLR’s as well as camcorders allows us to shoot at 60 fps or more than that, therefore make sure to choose the appropriate frame rate’s before you buy your camera.
Well, that was just a tip, we are not here to discuss about camera’s but we are interested in the Time Stretch feature of After Effects.
How to Slow down a video using Time Stretch.
Lets take a look at how you can slow down a footage in After Effects.
- Once you create a new composition and import your video into the timeline, right click on the footage or video layer and go to Time > Time Stretch.
- As you click on Time Stretch, a popup will appear which includes the settings you require to alter the speed of that layer. The default Stretch Factor is 100% which is for normal playback speed. To slow down the footage, you have to increase this value. If you change it from 100% to 200%, the footage playback speed will be half than that of normal one and the duration will be doubled.
- Simply change the Stretch Factor value from 100% to any other, but more than the default value. After that click OK and it’s done.
How to Speed Up a video using Time Stretch.
Speeding up a video using Time Stretch is as same as Slowing it down, all you have to do is decrease the Stretch Factor value from 100% to something lower than that. Something like 50% or so.
You can create a Time-lapse using this feature like the one I did recently. I changed the Stretch Factor value from 100% to just 3% to achieve the speed I wanted. Take a look at the video below.