sound/sync

[Michael Summers]

Thinking out loud here...
couldnt i record 16mm with a canon scoopic w/o sound sync at 24fps, and then while i'm filming record sound to my DVX in 24 fps, get the 16mm processed and then digitally tranferred and edit on my NLE with the sound from my DVX? just sync it up manually?

[Michael Summers]

its a yes or no questions guys...

[SergejIvanovits]

yes, you can. You can record your sound with what ever you like. You can use 24fps or 2455555fps to record your sound. The sound is without frames. It has duration. In your sound editor you choose the framerate in the timecode settings you want to use. It doesn't change the speed of the sound. If you change from 24fps to 50fps the sound is going to be the same but the timecode is different.

So, if you can find a common start point in the video and sound footage than the final video and sound going to be in sync.

But why don't you use a DAT or HDrecorder to record the sound? It has much better sound quality.

[discs of tron]

So, if you can find a common start point in the video and sound footage than the final video and sound going to be in sync.


no it's not. that's the whole point of sync sound cameras- their motors are crystal controlled to run at a totally consistent speed. you have to manually sync film to sound no matter what kind of camera you're using- it's just that with a crystal motor, you know the film speed is going to be consistent.

that being said, people do quasi-sync stuff all the time with non-sync cameras. some are better than others at running at a fairly constant speed. spring-wound cameras, for example, are a bad idea. shorter takes obviously work better than longer ones. also, if you slate both the head and tail of your shots, that gives you 2 sync points to work with so that you can strtch your audio to match your picture exactly.

[MichaelP]

The film is shot at 24fps.
The DVX100 is a 23.976 recording format.

You will need to slow down the audio by .1% to have sound sync after the transfer because the film transfer is done at 23.976 (thus .1% slower than what was originally shot on the set with the audio).

Michael

[Pointand Shoot]

Yes, it can be done... but don't think you'll come up with EXACT matching speed from the camera and the sound. You have to take into account your eventual frame rate on the NLE (will you use 29.97 or 24?), your sample rate on what ever you record sound on and so forth (44K or maybe 48K or something that records raw uncompressed files).

There is a lot of good info online about doing it, but don't think you can just run out and shoot and it will sync. I know from experience. Newer cameras like an SR3 work very well for this, but who's got one of those laying around. My advice would be to read all you can and shoot some tests before you go into a project. Also, avoid long takes, they will make you life a living hell.

[Barry_Green]

discs of tron is exactly correct.

The camera and the sound-recording device must run in exact sync with each other, or the sync will drift (sometimes dramatically). Oh, and the sound-playback device has to be at the same speed as well.

That's why crystal-sync motors came about, and why Nagras were crystal-sync too.

A slight drift in speed can throw your audio noticeably out of sync. Even the difference between 23.976 and 24fps results in the audio being two full frames out of sync after a minute.

So if you want to use a Scoopic, you'd have to use the crystal-sync model. If you used that, then yes, you'd be able to use your DVX as a sound-recording device.

For more info on this technique, go over to indieclub.com and look for user Mike Conway, whose film "Terrarium" was shot on non-sync scoopics, with audio recorded separately to video (I believe it was an XL1). He can tell you what it was like to work that way.

[SergejIvanovits]

Just use the analogue output from the DVX to record the sound and it will be in sync.

[Barry_Green]

? I don't follow that at all.

If you're shooting on film with a non-sync camera, there is practically no chance that the sound will be recorded in sync, no matter what you record the audio on.

The only two ways you can record audio in sync with a film camera is to use a) a film camera that uses a crystal-sync motor, or b) a film camera with a pilotone generator.

[SergejIvanovits]

I know what you mean. You are saying the filmcamera he is using can't hold the constans speed of 24fps. But it isn't as bad as in one moment it holds only 12 frames and in the other 25fps. Even to start opp the filmcamera with DVX in sync is not possible but the result in this case will not be so bad and with minor adjustment he can put the hole thing together.

[Barry_Green]

But that depends on how close the film camera is to being in sync. If it's just 4% off, that means the audio will be one frame out of sync after just one second, two frames after two seconds, and three frames after just three seconds.

Shooting sound with a non-sync camera is a royal pain.

Not to mention that a Scoopic is *noisy*. My strongest advice is to just forget the Scoopic and get a CP16 instead. Life will be soooooooooo much easier...

[kyledroid]

Barry, I just purchased a blimp for my arri 2 c. So, im gonna start shooting and recording sound in the same instance. My camera does not have a crystal sync motor( just a variable speed). In my case, will my audio sync up? If not, could someone please direct me to a vendor that furnishes crystal sync motors that will fit my cine 60.

[Barry_Green]

Without a crystal motor (or at least an attached pilotone generator), no, there's pretty much no chance your audio will sync.

Tobin probably makes a crystal motor for the IIC.

[kyledroid]

Barry, What about an AC sync motor? Can sound be synced with it?

[Barry_Green]

DOH! yes of course. Sorry I forgot that, and I shouldn't, I've had a half-dozen Auricons in my day... :)

Yes, Synchronous AC motors can provide sync just as crystal motors do...

[dasonras]

Yes it is not that difficult to do. Forget about timecodes and forget about crystal sync because it doesn't matter. That stuff only matters if you want the timecodes of the audio recorder (used to be standard DAT) to have the same timecode as the film strip.


All you need is a sync slate (clapper). Since you are editing non-linear... all you have to do is match the clap with the visual contact of the clapper.

Timecodes used to be important when recording analog audio and editing linear. But now with digital audio recording and non-linear editing the possibilities are endless.

P.S.

recording digital audio on the dvx... does not matter what fps speed you use. No matter what it will still be converted to 30p !!! It is still video!

[Mac]

For your info: Several years ago I was shooting a film in Arizona and my PortaDat died. Luckily I had my PD-150 along for the ride. I flipped the LCD screen around, left the lens cap on and shot a few frames of the timecode off the screen at the head of every take (I have a SMPTE slate on my PortaDat and I am used to working this way). When I got the film back I converted the audio rate (as above) and used the timecode to sync with picture... And, by-the-way, the audio was fine, not detectably different from the DAT I used on same shoot.. Point is, yes it will work (FYI, I was shooting with an Aaton which of course has a sync motor). It would even be easier if you used a bigger LCD for the slate (doesn't have to be a high end one either)...

[discs of tron]

Yes it is not that difficult to do. Forget about timecodes and forget about crystal sync because it doesn't matter. That stuff only matters if you want the timecodes of the audio recorder (used to be standard DAT) to have the same timecode as the film strip.


All you need is a sync slate (clapper). Since you are editing non-linear... all you have to do is match the clap with the visual contact of the clapper.



wrong. forget about crystal sync? forget about having your sound and picture in sync. please see my original post in this thread. it was written by someone who has exposed a lot of film, in crystal sync and in non-sync cameras. it's very simple, folks. if you want to sync sound to picture, you have to know that the picture was recorded at a consistent speed.

you're right that t.c. slates aren't necessary for shooting sync. but nobody ever mentioned t.c. slates. a sync motor, however, is necessary to shoot synchronous picture and sound. i've used mac's low-budg tc slate method btw, and it's great.

[soundguy]

Hello I am a sound engineer who has recently gotten to the movie side of things. I will possably be working on my first feature that doesnt include a DV cam. Now although its a great new experience Im learning more and more as I research that if I want to make sure sound syncs with the film I need a smart slate, and figure out how to sync it with the dat


I kind of got it. Ok this is what I think tell me if Im wrong PLEASE.
So the camera is an SR3 most likley at 24p, the dat Is not purchased yet, but I know should run off of a crystal based internal clock, as does the camera. As far as I have read I MUST have a smart slate to sync the dat to proper time code, clapping is not good enough. I need to connect a cable from the slate to the dat in order to "jam it" Now the question is where will the dat recieve the cable, and what does this do to keep everything in sync, does it need to be connected the entire time, Im sure I will think of a few more questions. If you can I would really love to hear exactly how to do this.

I always just thought as long as you clapped you were good but I guess not

alex