Syncing Dual System Audio

With the advent of DSLR video recording, the production world has truly come full circle regarding the relationship between audio and video sync. Back when everyone shot film, it was standard practice to record your images separate from audio and to sync via a clapper board later on. And for the most part audio recorders were analog tape formats and were not today's digital metadata-rich recorders. Video cameras have always been a god send in the fact that audio is recorded on board and saves so much time in post, not needing to sync files. But now once again, due to the limitations of DSLR cameras, we find ourselves dusting off our slates and recording separate systems once again.

There are two major advantages today with the way we record two systems for DSLRs versus film. One is the plethora of digital recorders with unique file naming, and secondly, the built-in microphone. A useful aspect of having unique audio file names is that an editor no longer has to listen to the verbal slate ID on every take to find what he/she needs to sync. Instead, by simply adding an extra box to the clapper for audio file numbers, the editor only needs to look at the slate to know which audio file is connected to the video. (See the above sample photo) This is a huge time saver, and really speeds up the syncing process. I would like to point out that there are great software plug-ins to assist with this process such as PluralEyes, but this tip is still useful for those filmmakers who don't own these apps or for when these apps can't make a proper sync.

Secondly, your cameras built-in microphone is a powerful weapon for multiple reasons. What if you don't have a slate? Or forget to slate? Or haven't synced for dailies? Your on board mic records fairly decent scratch audio that can make syncing much easier, so instead of looking for sticks, you can just listen for a particular sound on your camera audio and mixer audio to sync. Many times when on the run and just a in need of a quick sync reference, we will simply clap our hands very loudly, but the beauty is that you don't even need to be on camera, just be loud enough for both mics to pick it up. That on board mic might also save you one day should the worst happen and your "good audio" files fail you. I have seen where 7D and 5D audio had to substitute for the good stuff and to everyone's surprise it worked out pretty well. So keep your mics on and slate your file numbers and you'll be good to go.