Should tapes from 2 digital cams of the same event be exactly sync'd?

Discussion in 'Amateur Video Production' started by James, Mar 24, 2006.

  1. James

    James Guest

    You may have seen my post not long ago about running sound of a house PA
    board into a consumer camcorder to tape a friend's live performance.

    Since then, a new wrinkle has appeared. Someone is lending my friend a Canon
    XL1S, which I'm now scrambling to familiarize myself with before her gig
    tomorrow night - has adjustable record levels, XLR in's, etc.. Have never
    used a pro cam like this before, but there's enough commonality with my
    Digital8 that I'm not utterly lost in the woods and will be experimenting
    with it and studying the manual between now and then.

    What I thought I'd do in addition is run my Sony Digital 8 at another
    vantage point to have a second shot to go to when doing an edit of her
    performance. I'll be using the sound off the Canon obviously since it will
    be right off the board, though if feasible, might mix in some ambient sound
    off the Sony Digital 8 as well.

    I know that with 2 consumer analog anything - VCR's, Cams, tape decks -
    running at the same time, it's guaranteed that the tapes are going to be off
    from each other and not be in exact lock step. Is this the same with Digital
    cams or is the fact that they're digital going to mean they're going to
    track precisely the same way? I.e., when I get done, should I be able to
    load the contents off the digital tapes onto a computer and once some common
    point is aligned, they should both be in sync by default or no? I suppose I
    could manually shove the footage around to get it close enough for short
    periods but it would be a whole lot easier to just be able to transition
    from one to the other without all the jury-rigging.

    Is there some way to *make* them be in lock step? Wondering if there might
    be some way to have the one cam control them both while still being able to
    use the mics on the consumer Digital8. The only disadvantage being that if
    they have to be in close physical proximity, I won't get as great a variety
    of shot - i.e., one from basically straight ahead, one from a completely
    different angle though I could still do some transitions from near to far.

    Thanks for all input.
    James, Mar 24, 2006
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  2. James

    Kringe Guest

    I would think you will be fine. Especially if youre using your lesser cam
    just for cutaways... Using your good cams audio means you can throw up
    anything from the lesser cam and it will look in place... well.. if you
    avoid disconnects...

    Just my opinion thou - lets see what others have to say too
    Kringe, Mar 24, 2006
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  3. Exactly so. Every time you switch between the video from the
    two cameras, you can bring the video back into sync with the
    audio. Not really a difficult thing to do with most any modern
    non-linear video editing application. Don't worry about it.
    Richard Crowley, Mar 24, 2006
  4. James

    RS Guest

    Its not all that hard to sync them up in post. They may be a little bit
    of drift, and if so, that is easily corrected as well.

    All three of the most popular hobbiest editors (Vegas, Premire,
    FinalCut) have good Multi Cam plug ins available for low cost. Having
    used the one for Vegas on about half a dozen short videos now, I can say
    that it really makes the process easy.

    Ray Setzer video
    RS, Mar 24, 2006
  5. James

    peter Guest

    To make it easier to sync, avoid stopping the camcorders -- shoot until the
    tape ends.

    Usually you can sync the video in video editors using video as a rough
    guide, then the audio wave as a fine guide, and then use the video again as
    the finest guide (at frame level). If you can catch some camera flash, you
    can use those to sync.

    The XL1 may have noticeable audio drift after 1 hour. If that happens, just
    cut out a few frames from the audio.
    peter, Mar 24, 2006
  6. James

    Fletch Guest

    James wrote On 03/23/06 20:49,:
    If I recall the XL1s has SMPTE onboard. So that should be your primary reference. The other, if you
    import them to a PC/Mac based editor later, should not be hard to slip and slide into sync at all.

    Use the onboard audio of the XL1s as a reference, too, if you are recording the audio from a
    different source, such as a multi-track. If you have a DA-88 with sync card, you can link the deck
    and XL1s up and they'll track together.

    I'm just getting into video myself, so my recommendations may contain flaws.

    Fletch, Mar 24, 2006
  7. James

    Tim S Kemp Guest

    I regularly use 2x XM2, a cheap canon consumer camera and an old Pansonic
    camera, along with various rental sony / canon kit. Sometimes using
    longplay, and over 1.5 hrs of tape none of the above drift. Tend to record
    audio to minidisc, laptop or CD recorder HOWEVER have noticed some clock
    drift on a CD player I was using for playback on a location job...

    I never record from the desk to the camera for audio - XL1 is better than my
    XM2 but still noisier than a pocket minidisc recorder. Record to camera to
    give a backup and something to sync up to.
    Yep. Generally, although again I have limited experience. I always line up
    the captures on the timeline using the audio (look for a peak in the
    signal - or make one - a clapper is very useful). Once rolling don't stop...
    Tim S Kemp, Mar 24, 2006
  8. James

    Ed Anson Guest

    Several people have correctly advised that you should have no trouble
    syncing the video from two cameras in post. But the sound is another
    matter. At any point, you can use sound from one camera or the other --
    but never both. If you try to mix them, you can be sure to have strange
    results due to inevitable timing differences. If you want to mix the
    sound from two recorders they need to have synchronized word clocks, and
    that's not an option with consumer equipment.
    Ed Anson, Mar 25, 2006
  9. James

    James Guest

    That's my option, period. PA board to the cam.
    James, Mar 25, 2006
  10. James

    James Guest

    Right, will be using the audio from the XL1 which is supposed to be coming
    off the PA board. I primarily want the alternate angle shots from the other
    cam, possibly to use its sound to add in lightly as ambient sound but it's
    not imperative. Of course, during any cutaway shots to the second cam,
    they're still going to have to be in agreement at least during those points
    for the audio to match the video.
    James, Mar 25, 2006
  11. James

    Ed Anson Guest

    Cutaways are no problem at all. Just switch to the alternate video but
    use the XL1 sound all the time. If you keep both cameras running the
    whole time, they will tend to hold sync. In the worst case, you might
    experience a frame or two of drift by the end of the hour. I do that
    with video all the time. But I never try to mix the sound from two
    cameras unless I want it to sound strange.
    Ed Anson, Mar 25, 2006
  12. James

    James Guest

    Well, turns out it was a moot point. I was under the impression that there
    was going to be a space cordoned off for the cams with a clear view, but
    turned out no such arrangements had been made. I had to squeeze the XL1S
    into a space in front of the sound board and shoot through the crowd.

    Luckily I had thought to bring a small monitor with me, since the only place
    where I even had room to stand to operate the cam was on the wrong side to
    use the viewfinder...grrr... I spent the whole time working the cam,
    looking behind me at this monitor I had on top of the sound guy's rack.
    Wasn't any way in hades I was going to try to set my other cam up and leave
    it unattended in this joint for some drunk cowboy to knock it over.

    The video is okay, but isn't nearly as nice as I would have liked to make
    it. A second cam would have really helped. One thing I noticed is that the
    image tended to oddly drift a bit, apparently due to the steady shot. Also
    discovered the XL1S has a dead pixel which became apparent when someone
    danced in front of my line of sight and during darker moments, but at least
    the sound guy did a fantastic job. The sound is superb, with excellent
    balance among the instruments and vocalist, with good levels and just a
    touch of ambient audience sound. Unfortunately, the sound seems really out
    of character with the mediocre video.

    Oh well...thanks for all input.
    James, Mar 25, 2006
  13. James

    DanR Guest

    The 2nd camera would have been nice for adding crowd sounds (applause) as a PA
    mixer would not use crowd mics.
    DanR, Mar 26, 2006
  14. "DanR" wrote ...
    And even if you put the 2nd camera adjacent to the first, locking
    it own for a wide ("cover") shot would free up the first camera
    for getting closeups, pans, etc. Having the combination would
    give you not only a "variety" (of at least two) of shots, but would
    give you the wide shot to cover akward moves with the "primary"
    Richard Crowley, Mar 26, 2006
  15. James

    James Guest

    There wasn't even space to do that anywhere that provided a useable vantage
    point. This place is literally built to be like an old barn, with support
    posts around the perimeter of the dance floor that limited where you could
    stick a camera and not get one of these posts in the shot. I was just lucky
    there was a relatively clear view where I was. In the immediate space where
    I was was a large sound board and the sound guy had to stand at his board,
    and some other gear of his took up whatever other space there was.

    Just a really bad setup to do video unless you had the cams mounted on the
    rafters or something going to a real video board and it wasn't that
    elaborate of an exercise. They might have made such accomodations for some
    of the big name acts that come in from time to time but they were basically
    doing my friend a favor letting her make a tape in the first place.
    James, Mar 27, 2006
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