October 13, 2014 at 12:19AM


Please explain the relevance of clapping before a take for the purpose of syncing sound

Today, I came across two instances where something that I fail to articulate because I did not understand it was mentioned.

It vaguely had to do with clapping before a take just to sync audio with video. And that's what I do not understand.

The two instances I came across are:

1) An answer from a thread on this forum itself:


"Also, just in case you didn’t already know this, if you’re syncing sound in post and you don’t have FCPX or Plural Eyes, be sure to get the actors to clap at the beginning of each take so you have something easy to use to line up the sound with the video."

2) In this video, please watch from 22:58 onwards or thereabouts.



It's for syncronize the sound and the image is you don´t makes a dub.

October 13, 2014 at 7:16AM

Ragüel Cremades
Film producer and director

Ah, the poor person's slate! In editing, you line up the part of the audio waveform with the peak (the handclap) and the frame of the video where the hands come together, and voila! -- your audio and video are synchronized.

October 13, 2014 at 10:39PM

Minor Mogul

For perfect syncro, in the video, you have to mark the frame just before the handclap hits the clapperboard. And then sync that with the peak of the sound.
The frame before boths come together!
I know from experience and I've also check it out with many sound designers.

October 14, 2014 at 2:40AM

Gon Caride
Shortfilm Screenwriter & Director

Besides the explanations given here, when working with a multi-cam setup, it becomes crucial for syncing the cameras together for a proper multi-cam workflow.

October 14, 2014 at 4:20AM

Daniel Falcon
Director, VFX artist

As others have said, it’s an easy way to line up the video with the audio, as the clap is something very visually noticeable and also very noticeable in an audio waveform. Thus, you simply find the two moments in your editing software and line them up.

This was necessary when film cameras did not record audio with the picture. They would use a slate that had the shot and take information written on it and clap it down at the beginning of each shot after they read the information on the slate. You’ve probably seen this in many behind-the-scenes shots or movies that involve showing the moviemaking industry. Most professional films still use something similar.

Software like PluralEyes and the built-in “synchronize clips” feature of Final Cut Pro X can help make this unnecessary by analyzing audio waveforms and syncing clips for you, but it still doesn’t hurt to do the clap.

October 15, 2014 at 2:18AM

Ryan Toyota
Graphic Designer / Typographer / Video Editor

Creates a spike in the audio that is easily distinguishable for audio syncing. Sometimes using programs like "PluralEyes" and those "synchronize clips" features that Ryan above me has mentioned, sometimes, when I'm in a super efficient work flow and 110% in the mode, I just do it manually. Not sure why! I suppose I like to be a little more hands on.

October 16, 2014 at 5:42AM

Matt Bastos

It works even if the camera has no audio and you have a separate audio recording, we call this dual system sound.
as others have said, line up the video of the clap with the audio peak you see. I have plural eyes, but never use it, just lining the sound and video by wild sync goes fast

January 1, 2015 at 12:35PM


What everyone else has said, but if you're not actually recording audio internally for automatic syncing purposes, using a slate of some kind comes heavily recommended. One day of the last project I worked on used clapping-only and it took me several extra hours syncing the video to the sound because a few files got corrupted and I couldn't always rely on the next take of video matching the next take of audio. Not being able to see "Scene 1A Take 3" when you don't realize Scene 1A Take 2 is missing can cause some serious stress when trying to match things up.

Chances are you won't have corrupted files (rare but real downside of ML RAW), but being able to see right off the bat which shot you're looking at will make post a far more pleasant experience. (For that reason, even if you aren't syncing audio, a clap board is still a useful tool.)

February 2, 2015 at 8:13PM

Alec Kubas-Meyer

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