Massive audio drift capturing DVCPRO 50

[Jerry Hofmann]

Could there be something wrong with camera 2’s recording? can you make a clone of it?

Jerry

[Robert Bengraff]

They all play fine, although I obviously have TC issues. What puzzles me is why I can’t at least do a free run capture (capture now). The tape plays perfectly all the way to the end without issue. Shouldn’t free run just capture what I’m seeing? I know I’ll lose time code, but at this point TC is the least of my issues.

[Dan Riley]

I’ve been doing a project that used two SDX900s at DVCPRO50
and the crew did the same thing in the field as your shoot,
they jam-synced the two. This is always trouble.
Tell your crews never to do this. Use a generator and
feed both cameras from it. Do this, or use visual or aural cues.
Anyway, I had many timecode problems from the slaved camera
timecode.

The other thing is, if it was the Panny 900 camera,
there are many record settings for frame rate etc.,
and it may be that your camera two wasn’t set the same as
camera one. This might account for the audio and timecode
errors. Just a thought.

How are you capturing? through an SDI connection or firewire?

Dan

[Robert Bengraff]

Wow. Glad to know that I’m not alone. I think the cameras were match up ok. What I have noticed is that the tapes that captured out of syc had one thing in common. After capturing I did a properties check and found that the audio rate was always off. Instead of 48k I was seeing things like 47671.23k 46373.10k, etc. I think that I will be able to muddle through, but based on the TC issues that you discovered, all hopes for multiclip editing are long gone. The isolated TC generator is a great idea for next time.

Thanks much,

r

[Dan Riley]

You can still use multiclip. You just pick some other thing to sync to
than timecode, like the beginning of a word in the take. That’s what I did
and it was fine, but a bit tedious because you have to go to each take
for each camera and mark in times, then (as I did) back up two seconds
and hit “in”. (so I had some front end on each take)
Not nearly as easy as using timecode to make multiclips
but still doable.

Dan

[Jerry Hofmann]

I agree about the generator… you’d think you wouldn’t need it, but it always seems to cause problems in post if you don’t use one.

Capture now will capture the timecode unless you also choose “non controllable device” as the device control setting.

Try shorter captures? There is a setting to check too… to force the audio to sync. It’s in the General User Preferences… sync audio capture to video if present…. might try it both ways.?

Jerry

[Tony]

The proper and most bullet proof method is to use a master timecode generator and black burst generator which providing genlock to the cameras.

Or you could use Denecke SB-T timecode boxes which provide a crystal generated timecode generator along with black burst.

Even if you just looped out of one camera to another this will work if the second camera is jam synced properly to the first camera which requires making sure all the camera menu settings are properly set. Sending the second camera a reference source to genlock to would be ideal also.

At times like this I hate to reminder you that hiring a qualified video engineer or EIC would have been money well spent versus shelling out the extra daily rental for the vtr to try and trouble shoot what went wrong on the shoot.

Apple will not be able to provide any assistance on this matter as it is clearly an issue with the original field production workflow and not a FCP issue so don’t expect much from them.

By the way how are you capturing the footage Firewire, SD-SDI, analog. How are you capturing the audio?

Do the two routes video and audio match ie digital with digital or analog with analog not mixed.

Tony Salgado