Re: RED Camera Audio Workflows

Plus or minus one frame is typical in any digital camera. It depends on
what you are using as a reference to determine sync.
If the TC is not in phase with the camera sample clock (Genlocked) then it
will vary plus or minus up to 1 frame in either direction on every shot..
Same is true with visual capture of a TC slate. Since the Slate TC
Generator's frame transition is not aligned with the camera shutter or CCD
sample clock it is never in perfect sync and the closest reference is the
last full frame number received. Then add to that variable the fact that
digital cameras have encoding time where they encode the sampled frame into
a digital bitstream, add a lookup table (if not recording RAW), color space
conversion, data compression etc. This all takes time and there is no
standard way to indicate or compensate for this latency. Some cameras try
to compensate for this by delaying the internal sound the same amount to
match, but variable bit rate compression schemes can make this a bit of a
crap shoot. Especially if you are checking sync or aligning the sound based
on a single frame from a variable bit rate group of pictures. Your double
system sound may not be offset by the same amount so the TC will be shifted
slightly if you compare the audio from the separate recorder with that of
the internal camera audio.

I wouldn't sweat 1 frame too much. After all, traditional film syncing by
using a Clap-Board has never been better than plus or minus 1 frame since
the inception of double system sound in movies. This is because the camera
shutter is closed 50% of the time, it is never possible to get better than 1
frame accuracy. (the slate could have clapped just as the shutter closed or
just as it opened).

----Courtney



<tork4535@xxxxxxxxx> wrote in message
news:5f21ca41-7414-4f33-b966-6972773f5e30@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Nov 25, 7:18 am, Pascal Van Strydonck <pascal...@xxxxxxx> wrote:
Allright my two cents on this. Think about it, Coffee in LA, Forum
Worldwide, Questions coming from Worldwide, People in LA on this forum
( a lot but not all ), Amount of time Coffe will spend researching and
answering on this forum ( A LOT ). What is wrong with giving
advise??? You are not sure about something then ask the questions on
the forum. I don't care about where the answer is coming from as long
as it is right. We are all grown up ( not IDIOTS ), we all know how
this is played. Why do we choose a certain MFG or Retailler aside
from the product they have, it's all about service. Now if Coffee
goes out of his way to help us out, then BIG THANK YOU GUYS. Help is
always welcome.

Pascal

I know this seems a bit off topic but I'd like to make a few
observations about the Red :-).
I have worked with these cameras a few times in the last year. Always
ran my system at 23.976 with a Deneke SB-T on the camera. Sync was
always off by a frame, sometimes two. We could jam everything -
sound, cameras, and slates - shoot a slate and import that file into a
mac on set and it was rarely frame accurate. Because of this I have
had to send a wireless guide to camera. This seems like such a hassle
when the technology promises such simplicity.
Disappointed again.

Warren

ps. the post on these projects was at 23.976 as well.


.

Relevant Pages

  • Re: Tri-level sync, double-system, safe or not?
    ... I'm not sure how it became a sound issue in the ... about camera sync again. ... still insist on REC RUN timecode. ...
    (rec.arts.movies.production.sound)
  • Re: Help: a handheld image processing device
    ... between and after frame captures. ... NOT have a USEB/IEEE1394/or other interface. ... LCD interface and camera ... LCD display and fairly high res CMOS cameras that will plug in to the 20 pin ...
    (comp.arch.embedded)
  • Re: Why are Digital camera images made wrong?
    ... If Photo Paper is available in 4:5 proportions why aren't the camera ... I'm guessing that if the camera manufacturers even gave this any ... of a 35mm frame or digital sensor and the paper products and dime store ... standard aspect ratio frames but oddities like 4:1 or even 7:1 or God ...
    (alt.photography)
  • Re: RED Camera Audio Workflows
    ... many new editors are not used to ever seeing anything out of sync at ... will vary plus or minus up to 1 frame in either direction on every shot.. ... Same is true with visual capture of a TC slate. ... Generator's frame transition is not aligned with the camera shutter or CCD ...
    (rec.arts.movies.production.sound)
  • Re: 744T TC problems w/ Avid
    ... Timecode @ 29.97DF on everything, rec run on camera, wireless link ... They're saying that the TC lines up, but the audio is out of sync a ... camera and sound had exactly the same TC. ...
    (rec.arts.movies.production.sound)