Synchronizing audio with two cameras - please help

asafb wrote on 7/11/2002, 12:43 PM

Hello, I am going to be recording a classical solo piano concert and I will most likely be using 2 cameras and microphones. The sound will be going into DAT because the PD150's audio is a piece of ....

Point is, I already know how to easily synchronize one angle with the sound. It's not a problem. But after about 2 minutes, I'd like to crossfade to the 2nd angle (2nd camera).. how do I make sure that that 2nd camera (angle) will be synchronized correctly in that exact place?

Okay visually here's what i want (in the timeline)

ANGLE 1 *************************************************************
WAVE FILE *************************************************************
ANGLE 2 **********
^this portion of angle2 will be zoomed
in to see just the hands!

so when do i hit record on the two camears, at the same time?

Comments

asafb wrote on 7/11/2002, 12:45 PM

i should also let you know that angle2 will not be right in the beginning, it will be in the middle:

Angle 1: Timecode 00:00:00:00 - 00:05:00:00
WAVE SOUND: Timecode 00:00:00:00 - 00:05:00:00
Angle 2: Timecode 00:02:00:00 - 00:04:00:00

Former user wrote on 7/11/2002, 1:07 PM

Record the whole song on both cameras recording from beginning to end. You might find you want to change between the cameras more than once or twice.

If the cameras are both rolling, once you get them in sync on the timeline, then it is easy to transition between them

To sync the two cameras, you need to find a movement or a note visually that you can match frame to frame between the two angles. Sometimes people take flash pictures at an event. These are good for syncing the two camera angles.

Tyler.Durden wrote on 7/11/2002, 1:11 PM

Hi,

The easy way is to record the performance all the way through on both angles, and place them both on the timeline one over the other in sync.

Wherever you want to cut to the other angle, split that track with the S key at the beginning of the shot and the end of the shot and *copy* the shot to a third track (on the top).

I have a brief tutorial on how to "call shots on the fly", but the basic idea of tracks is shown there too:

http://www.martyhedler.com/homepage/Multicam.html

HTH, MPH

SonyDennis wrote on 7/11/2002, 1:51 PM

That's what the Hollywood slate is used for, syncing picture and sound, and multiple devices if present. If you don't have one, have both cameras point at you before you tape the recital, and just clap one time, and there's your sync point.

I like the advice above about using a camera flash, if you didn't record your own sync point. Remember, it doesn't have to be something *before* the performance, it can be something *after* just as well, as long as both cameras are still rolling. You'll need to re-sync each stop/start cycle, so once you're synced, leave the cameras rolling.

I wish they'd make a way to sync time/date stamps on cameras just by pointing them at each other, using IR or something <g>.

///d@

Randy Brown wrote on 7/11/2002, 9:23 PM

Hey asafb,
I'm very close to buying 2 PD150s and audio is a big factor for me to consider. I read somewhere there was a problem with hiss in the older models but the problem had been resolved ; can you tell me please if yours is an older model and if your dissatisfaction is indeed due to hiss?
Thanks in advance,
Randy

asafb wrote on 7/12/2002, 4:06 PM

Hi Randy,

If you have AGC to "on", it is hissier than DAT -- in fact, honestly I never *ever* use audio from videotape, because it's just not as good as going digitally from DAT. This is just common sense. Besides, I'm fast in synching, so it's no big deal.

If you turn AGC off, it's *verry* hissy. I would recommend Sonic Foundry's Noise Reduction ;)

But listen Randy, it's a beautiful camcorder.

Caruso wrote on 7/13/2002, 1:52 AM

Ok, what's a PD150? Now I'm curious.

I second all sync advice given here. Another trick I use is to check alignment after syncing by enabling and playing both sound tracks at the same time. If you reduce gain on each track to around 50%, and, if, when played simultaneously, both tracks sound as one, you're in perfect sync. Any echoing would indicate misalignment. You can then fine tune the sync by adjusting one track in either direction, frame by frame, until the echo disappears.

I will use this method if the best sync points I can find are still not quite sharply enough defined so that I can insure absolute sync.

This last point is obvious, but hasn't been mentioned. When making your adjustments, make certain you select all the events on that audio/video track so that you don't inadvertently misalign audio/video within a track. You will want to bear this last point in mind as you edit your production also. I like and use the "third" video track idea mentioned above, where the desired cuts are copied to a separate (I refer to it as a 'master') video track. This leaves the original two tracks in tact.

Have fun.

Caruso

Randy Brown wrote on 7/13/2002, 9:35 AM

Thanks asafb,
The reason I was asking about the hiss is this: My plan is (was?) to use the audio from the camera ( I don't own a DAT deck)unless it is a musical event in which case I would lug along a PC and audio mixing board for multi-tracking. I'm putting together a package for the bank to get a loan for everything I need and am wondering if I should include a portable DAT deck. I hope I don't annoy you by asking you again if your PD150 is an older model (as I recall the issue was supposed to be resolved about a year ago and now offer owners of the older models a "fix" for the cost of shipping).
Thanks again,
Randy

Randy Brown wrote on 7/13/2002, 9:41 AM

Oh yeah, Caruso, if you haven't guessed yet , the PD150 is a mini DV camcorder made by Sony.
Randy

wcoxe1 wrote on 7/13/2002, 11:13 PM

Recently I accidentally zoomed in on my then current project. I was astounded by VV3's abiltiy to expand single frames to extreme lengths. It gave such extreme detail to the audio track when spread out like that I was amazed.

To make all this short, I used this ability to sync my next project. My ears were shot off in the war, or something, and I don't hear as well as I would like. So, I used the actual sound to get as close to sync as possible, then expanded the timeline near the beginning on a very obvious sound. I then adjusted the two sets (video and waveform of each angle) until the waveforms were pretty well matching. Since I was using one mike set for the three identical camcorders, the match was pretty well a perfect match. There is some difference, but there seems to be enough OBVIOUS matching ripple in the waveform that it wasn't a problem. Seems that this helped me when the old ears wouldn't.

Any comments? Anyone refined this idea, or am I just fooling myself?

stateofgracie wrote on 7/14/2002, 5:11 PM

I actually think that synchronising the AUDIO track is the best way of doing this, although it may take a bit longer. Also, if a performance is long, it may pay to check the synch by comparing the audio tracks from both cameras at beginning and end of the take to make sure that they haven't drifted. At a piano concert, a slight lag between audio and video may not be noticable, but if you're filming a drummer...
In fact, you're actually looking for audio to be synchronised with the video. Since the audio track of each camera is in synch with the video, you can align the two takes using the audio. I do this as suggested, by aligning the waveform of an event with lots of attack (snare hit, hand clap, whatever other noise is available), then listening to the two audio tracks mixed together to check for flanging effects. Zoom in on the audio to get better control for alignment.
You can even edit together footage from different performances this way. I have been editing a music show that was filmed on three different nights with two different cameras. I aligned the video to a soundtrack that was recorded separately into Vegas on a laptop, using a pair of room microphones and a direct out from the mixing console. If the tempo of a song varies between different nights, you have to cut between the different cameras more often. It actually works quite well, although it can be time consuming to make it look right.