Understanding FPS and Frame Rate in Slow Motion

Slow motion capture and playback presents a unique conundrum: when you slow down the playback, does the FPS (frames per second) increase or decrease? This article will unravel the mechanics behind slow-motion videography and explore how this affects the overall viewing experience.

How Slow Motion Increases FPS

Speeding up or slowing down the playback of a video doesn't physically change the number of frames captured during recording. However, it does affect the perceived speed of the action within the video.

In slow motion mode, the camera records at a higher frame rate than usual. This increased frame rate allows for more detailed and smoother playback at a slower pace.

Breakdown of FPS and Frames in Slow Motion

When filming in slow motion, a camera is set to a higher FPS - for instance, 120 FPS or 240 FPS - compared to the standard 24, 30, or 60 FPS. This setting captures more frames over the same period of time.

When the recorded footage is played back at the standard speed, the additional frames create a slower, smoother effect. In other words, the same amount of action is displayed over a longer duration, resulting in the perceived slow motion.

For example, if you record an event in slow motion at 120 FPS, each second of real-time action is captured as 120 individual frames. Playing this back at the standard 30 FPS means each second of original footage will last 4 seconds, making the event appear slow-motion to the viewer.

Playing Back at a Lower Frame Rate

A video recorded at a high frame rate might be played back at a lower one, further intensifying the slow-motion effect. For instance, a 10,000 FPS video played back at 30 FPS would be approximately 1/333 of real speed, creating a highly exaggerated slow-motion effect.

Consider an event that takes one second to happen in real life, such as breaking a glass. If this event is recorded at 2000 FPS, it captures 2000 individual frames over that one second. When played back at 30 FPS, these 2000 frames will last for approximately 66 seconds, drastically slowing down the action and making the glass breaking process appear highly exaggerated and dramatic.

Conclusion

The key to understanding slow motion and frame rate in video is recognizing the difference between recording and playback settings. While the FPS during recording is higher, the playback speed determines how the action appears to the viewer.

By adjusting both the recording and playback settings, videographers have a powerful tool to create dramatic, slowed-down sequences that can captivate and engage their audience. Knowing the interplay between these elements is crucial for anyone interested in mastering the art of slow-motion videography.