Syncing pro tools hd and 3 camera live video shoot

[dvillage]

I'm consulting on a live video shoot that my sister is doing and while I'm fine in the audio world I'm not that well versed when it comes to syncing things together while doing a live shoot. My question is what is the most simple way to make sure the audio is in sync with what is being shot? We are renting a turnkey PT Hd system with Sync I/O. Is that all I need?

I've read a few older posts on here about recording the timecode on an audio track but not sure what happens after that. Is the timecode being recorded while the audio is being recorded? Is it possible to put PT into external and have the timecode from the camera trigger the PT while I'm recording the audio tracks? If that doesn't work then what is the procedure after the timecode is recorded? as you can see I have a few questions......... haha.

The camera being used I believe does not accept timecode but they will be giving the PT operator a sync feed.

Anyway the shoot is in the Burbank area. I'm in L.A., Winnetka to be more specific. My sister is also trying to find someone that she could pay to come by for a couple of hours just to get things up and running. This is a non profit company but I know there's a little bit of money for this. I must say trying to find info on this topic has not been easy and I know a few people in this business. Obviously not the right ones........ haha.

Thanks for any info and help on this.

jeff

[dvillage]

One more thing. Do I also need word clock?

jeff

[JFreak]

It seems your camera needs to be connected to Sync device that clocks your PT session. Sync I/O is no longer supported, the similar device is called Sync HD nowadays. It also provides word clock to interface(s) and other digital devices you may be using.

[kelsey]

What cameras are you working with? That is the first most important piece of info that will dictate how you move forward. I do lots of this type of show recording and there are a variety of approaches I have seen used. A bit of general info that may help:

Timecode is just a metadata stamp which will allow you to align the audio recording with the video files. You can choose which device is the master, but all units need the same TC to automatically sync on a timeline in post. LTC, which is the signal that feeds each device timecode can be recorded onto an audio track if need be, but it's less common and requires more steps to work with in post.
If you want the cameras to stay in sync with pro tools over the length of the show and not drift you need to genlock the cameras to the sync hd. You can do this with a BNC cable or if you need more freedom you can get clocks for the cameras like the ambient lockit boxes. This of course assumes your cameras accept genlock. Professional cameras do, pro-sumer cameras may or may not. A production sound mixer does this camera/sound sync every day and can help you out, or you may have success renting lockit boxes and getting some advice from a production sound rental house like Trew Audio.

[Darryl Ramm]

Why are you using Pro Tools to live record? Especially if you are doing the mixing/post later and won’t be there. Why not rent a field recorder and make it (potentially) easier for folks... I would assume more video people will be comfortable using a field recorder? How many audio tracks are you recording?

[kelsey]

Originally Posted by Darryl Ramm

Why are you using Pro Tools to live record? Especially if you are doing the mixing/post later and won’t be there. Why not rent a field recorder and make it (potentially) easier for folks... I would assume more video people will be comfortable using a field recorder? How many audio tracks are you recording?

Filed recorder options are limited for high track count shows and require external input options. It's quite common to record high track count shows on a computer.

[dvillage]

Thanks everyone for the responses.

The camera is a Sony Z450. It's a 3 camera shoot with about 16 channels of audio and about a 30 to 45 minute live shoot with maybe a couple of pick ups at the end. As it stands now we are going to send code to the main camera via a Horita Black burst which I understand will also lock the PT session via the sync I/O. It's and older PT rig so thats all we could afford. The other 2 cameras will be jam synced.

Is this as close as we can get to sync with what we are using? Can we use the ambient lock boxes with the older sync I/O? I know the 2 jam synced cameras will probably drift towards the end and will have to fix in post unless we can use the ambient sync boxes with the sync I/O.

Once again thank you all for your replies.

jeff

[kelsey]

With your setup the one cam that is fed blackburst will stay in sync with the audio, the other two cameras may drift over time. Editorial can slip edit them to bring them back in time.
The lockit boxes would be jammed from the sync io and live on the other two cameras keeping them from drifting over time if that is important.

[Philthy]

Originally Posted by kelsey

What cameras are you working with? That is the first most important piece of info that will dictate how you move forward. I do lots of this type of show recording and there are a variety of approaches I have seen used. A bit of general info that may help:

Timecode is just a metadata stamp which will allow you to align the audio recording with the video files. You can choose which device is the master, but all units need the same TC to automatically sync on a timeline in post. LTC, which is the signal that feeds each device timecode can be recorded onto an audio track if need be, but it's less common and requires more steps to work with in post.
If you want the cameras to stay in sync with pro tools over the length of the show and not drift you need to genlock the cameras to the sync hd. You can do this with a BNC cable or if you need more freedom you can get clocks for the cameras like the ambient lockit boxes. This of course assumes your cameras accept genlock. Professional cameras do, pro-sumer cameras may or may not. A production sound mixer does this camera/sound sync every day and can help you out, or you may have success renting lockit boxes and getting some advice from a production sound rental house like Trew Audio.

Sorry to go off topic, but I'm curious why two digital disc-based recording systems are still doing things like drifting apart in time? We're dealing with sampling rates of tens of thousands to a second, yet systems aren't independently keeping good enough time? How big a problem is this- say, what kind of drift might the OP expect over a 40 minute program? I've never met drift that I couldn't fix by correctly matching frame rates, but when I'm worried about sync it's usually just 3-minute videos- too short a time to notice the problem?

[kelsey]

Originally Posted by Philthy

Sorry to go off topic, but I'm curious why two digital disc-based recording systems are still doing things like drifting apart in time? We're dealing with sampling rates of tens of thousands to a second, yet systems aren't keeping good enough time to stay locked? How big a problem is this- say, what kind of drift might the OP expect over a 40 minute program? I've never met drift that I couldn't fix by correctly matching frame rates, but when I'm worried about sync it's usually just 3-minute videos- too short a time to notice the problem?

It all comes down to clock accuracy.
In a 3 minute clip the drift between clocks will be less than a frame which would not be detectable. In an hour long show a couple frames drift is not unreasonable to expect depending on the camera. Now if you have two cameras, both drift 3 frames in opposite directions your cameras are out 6 frames at the end of the show. That is a very noticeable sync issue if it isn't fixed one way or another (clocks or slip edits etc.)
Modern digital cameras only need to sample roughly 24 times per second, so the clock doesn't need to be as precise as an audio clock does. However over an hour 2 audio recorders will also drift from each other enough to cause phase issues unless their clocks are synced.
The reason lockit boxes are used to genlock the cameras is because they are essentially portable battery powered clocks that have similar accuracy to high end audio equipment. That will keep multiple cameras in sync within 1 frame in 24 hours.
Does that answer your question?