Slow-motion video is one of the coolest video effects where time appears to slow down. You might use a slow-motion video to emphasize a specific scene or slow down an action you wouldn’t normally see in detail, like a flower opening its petals or a balloon bursting.
In order to understand what it is and how to slow-motion a video, you need to know about frame rate (fps), which is the number of still images making up one second of the video. With slow-motion video, moving images are displayed at a rate that appears slower than in real-time. In order to achieve this, you must capture frames at a higher rate than the intended display speed. For example, capturing a video at 60fps (frames per second) means when you watch the video, you’ll observe 60 frames per one second of the video. By putting this video onto a timeline set to playback at a lower fps rate – such as 20fps – the one-second video will now take two seconds to play.
Slow-motion video is normally recorded at the highest frame rate possible, and many cameras offer rates as high as 1540fps. It’s possible to shoot slow-motion videos on your smartphone, though and 60fps, 120fps, and 240fps are more common.