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qestion about double-system sound recording


Jerry Murrel

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I've got a question about audio - not sure which forum to post to.

 

Most of what I've shot myself has been MOS - but I'd like to buy a

field recorder to use with my Arri 35BL.

 

I'm under the impression (perhaps misguided) that I need to buy

a recorder with SMPTE TimeCode generation capabilities.

 

I've considered the Fostex FR2LE and some Marantz models, but

I don't think these generate timecode.

 

Is it really necessary to have timecode to keep audio in sync with

film? My camera motor is crystal controlled and frame accurate,

but didn't foks use Nagras for years and still maintain sync?

 

Surely the old analog reel to reel Nagras didn't have timecode,

did they? If I'm not using a Deneke timecode slate, is it really

necessary to spend the extra money something more expensive

like the Sound Design model? I realize the film stock has timecode

and keycode - is it worth the extra expense to have timecode

on my recorder also?

 

-Jerry Murrel

Little Rock, AR

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"is it really necessary to spend the extra money on something more

expensive like the Sound Design model?"

 

Correction: I meant to refer to the brand "Sound Devices", such as

sold by Coffey Sound in LA.

 

-Jerry Murrel

Little Rock, AR

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You don't need timecode. Filmmakers used film cameras, nagras (and older equivalents), and dumb slates for many, many years before timecode even existed.

 

At it's simplest, only three things are required for sync sound films:

 

1. A film camera with some method to keep the speed absolutely constant at 24fps. Crystal control is the usual way to do this.

2. A sound recorder to keep the tape running at a constant speed. I believe crystal control is also usually used for this.

3. Some way that is both visual and auditory to sync them up. Slates fulfill this requirement. You simply line up the slate clap on the audio with the first frame where the sticks are together for picture. Repeat for every shot.

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The Nagras had pilotone sync, which was usually crystal generated when shooting with a crystal speed controlled camera. The stereo Nagra had the option of time code. The old slate method works extremely well with a crystal type accuracy, constant speed sound recorder with or without time code.

Edited by Brian Drysdale
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2. A sound recorder to keep the tape running at a constant speed. I believe crystal control is also usually used for this.

 

Almost -- The thing you need on the tape is a way of locking the sound to an accurate time reference. This can be done with a recorded channel of time code, or a recorded sync pulse, or even sprocketed magnetic film. Non-sprocketed magnetic tape requires some sort of extra channel with a recorded reference. The physical speed of a non-sprocketed tape can vary a little.

 

Recording to digital files, the sample clock can be your time base.

 

 

 

 

-- J.S.

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Almost -- The thing you need on the tape is a way of locking the sound to an accurate time reference. This can be done with a recorded channel of time code, or a recorded sync pulse, or even sprocketed magnetic film. Non-sprocketed magnetic tape requires some sort of extra channel with a recorded reference. The physical speed of a non-sprocketed tape can vary a little.

 

Recording to digital files, the sample clock can be your time base.

 

 

 

 

-- J.S.

 

Isn't that (I'll quote myself) "tape running at a constant speed"? :huh: :P

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Isn't that (I'll quote myself) "tape running at a constant speed"? :huh: :P

 

No, the physical speed of the tape with nothing but audio on it can't be made accurate enough. It has to have a channel of something -- sync pulse or time code -- in addition to the audio. Think how a projector or Moviola would work if it had smooth rubber rollers instead of sprockets -- it would drift out of frame all the time.

 

 

 

 

-- J.S.

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No, the physical speed of the tape with nothing but audio on it can't be made accurate enough. It has to have a channel of something -- sync pulse or time code -- in addition to the audio. Think how a projector or Moviola would work if it had smooth rubber rollers instead of sprockets -- it would drift out of frame all the time.

 

-- J.S.

 

Thanks to Chris Keth, Brian Drysdale and John Sprung for sharing your knowledge here.

I really appreciate each one of you taking the time to respond.

 

I guess my follow-up question on this subject would be about the Fostex FR2LE - given that

it doesn't generate SMPTE Timecode, would it still run at a constant speed; that is constant

enough to keep the audio in sync with the crystal-controlled camera motor?

 

I'm also wondering if buying an old analog Nagra might turn out to be even more expensive

in the long run, considering maintenance and repair issues...

 

-Jerry Murrel

Little Rock, AR

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I'm also wondering if buying an old analog Nagra might turn out to be even more expensive

in the long run, considering maintenance and repair issues...

 

-Jerry Murrel

Little Rock, AR

 

And availability of tape. I believe the one company that still made it quit about 3 years ago.

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And availability of tape. I believe the one company that still made it quit about 3 years ago.

 

Indeed. Some retail companies still have somewhat large batches of magnetic 2 track (1/4 inch) tape in storage. Specifically, I know of 1 or 2 that still carry it, I can imagine there are more out there . . .

 

Maybe it will come back in style, much like vinyl did a few years back.

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I'm also wondering if buying an old analog Nagra might turn out to be even more expensive

in the long run, considering maintenance and repair issues...

 

A Nagra in good shape that is well cared for will generally outlast any digital sound recorder. Much like a well kept film camera will outlast a video camera, generally speaking. Parts for them may be trickier to find, but if they come down in price picking up a couple units for parts could solve that problem.

 

I know someone who has a Nagra. In the ten years I have known this person, DATs, Mini Disc, hard disk, solid state etc recorders have come and gone, while the Nagra keeps on going strong with minimal servicing.

 

Older analog equipment was generally built to last. Service techs may still be found in major metro areas, don't long for how much longer though. Just got to find one before buying the Nagra, preferably.

 

Every time I use my 30 plus year old motion picture cameras, or consider shelling out thousands of dollars for an HD camera, I wonder where the current crop of top of the line HD cameras will be in 30 years time . . .

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Some older movie cameras have a small AC generator on them that generates a 60Hz signal when the camera is running at 24fps. The signal is then recorded on the neopilot track on recorders like Nagras (there were some others, notably the Uher Report-L). (Note: In countries where filming is at 25fps neopilot signal from the camera is 50Hz)

 

Since the camera itself is generating a signal that linearly varies in frequency with camera motor speed variations, the neopilot signal frequency recorded on the tape recorder is proportional to camera speed. No crystal or synchronous motor is required on the camera. The neopilot track's playback can be subsequently used to sync the reel-to-reel playback to a sprocketed magnetic film recorder using a synchronization device called a resolver. That sprocketed magnetic film sound master will be frame for frame accurate to the film from the camera for further editing. I've seen several Arri II's with 50 or 60Hz neopilot generators on them and years ago owned a Bealieu R16B with a neopilot generator on it.

 

http://en.wikipedia.org/wiki/Nagra

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Some older movie cameras have a small AC generator on them that generates a 60Hz signal when the camera is running at 24fps. The signal is then recorded on the neopilot track on recorders like Nagras

 

True, and the sync pulse required a hard wire from the camera to the recorder. This was always an inconvenience and a point of failure.

 

 

 

 

-- J.S.

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  • 1 year later...

On its own your ARRI camera is accurate. On their own any audio recorder is accurate. But, you need the two devices to be accurate TOGETHER, which is where timecode comes in. Timecode was a pretty big step forward in helping to sync audio and video and it saves tremendous time in post production when using FCP, Avid, or any other non-linear editing system. Here in 2010 it is absurd to be shooting anything without using timecode. To be spot-on with your audio and video or film buy a good audio recorder (Sound Devices, Zaxcom, etc) and jam timecode from the recorder to the camera while ALSO using a timecode slate or dumb slate. This will give you two methods of syncing the audio and video together. Using only a slate will tell you that the sync point is locked but that doesn't eliminate drift over a long period of time. Timecode jam helps eliminate this problem. No two timecode crystals are created equally so therefor their clocks will be slightly different. Now, this may only be one or two frames over the course of the day but any amount of difference is unacceptable.

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For a feature I shot on digital, I opted to record sound separately, because my camera was somewhat limited in how it could capture audio, and I wanted a higher quality source.

 

I used a marantz solid state recorder, and then a simple slate to link the two. On one shoot I forgot the slate, in which case I just clapped my hands for the camera.

 

It was down and dirty, but worked fine, so yes it is definitely possible to do sync sound without the added expense of SMPTE and timecode and all that (damned if I understood how all that works anyways!)

 

BR

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Jerry,

 

If I understand your setup correctly, you have a 35BL that runs at crystal controlled speeds, but has no internal time code module. In that case, you'd need both time code on your sound recorder and a time code slate in order to take advantage of the convenience of time of day code in syncing your dailies.

 

It's your call. You can work with crystal on both, no code, and hand sync everything. We did that for years with the Nagras, but not any more. Or, for not a whole lot more money, say a couple grand, you could have the convenience of finding things by the numbers. You do still need to look carefully at the sticks, as the generators drift a little. Jam them together at the start of the day, and again when you come back from lunch.

 

The good news is that you can go ahead and try it without time code, and later buy one of those external lockit boxes and the digital slate, when you have the cash. Lockits are much more accurate than the internal code generators in audio gear, so they're widely used instead of the internal code generators.

 

If you use any professional post facility, they'll expect time code, and probably charge you a bunch extra if you don't have it. So, in that case, it may actually cost less to get the lockit and slate.

 

 

 

 

-- J.S.

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  • 2 weeks later...

you can use a portable battery operated 4 track digital recorder, you can get used ones at daddy's junky music store for $50.00, all you need is a good mike! dont go to crazy! just make sure the recording sample rate is up to date.

Edited by alfredoparra
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  • 1 month later...

A Nagra in good shape that is well cared for will generally outlast any digital sound recorder. Much like a well kept film camera will outlast a video camera, generally speaking. Parts for them may be trickier to find, but if they come down in price picking up a couple units for parts could solve that problem.

 

Thanks Saul,

 

The Nagra 4.2 may no longer be practical from the standpoint of post workflow;

but I love those old machines - they were jewels.

 

-Jerry Murrel

DP, Little Rock

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Jerry,

 

If I understand your setup correctly, you have a 35BL that runs at crystal controlled speeds, but has no internal time code module. In that case, you'd need both time code on your sound recorder and a time code slate in order to take advantage of the convenience of time of day code in syncing your dailies.

 

It's your call. You can work with crystal on both, no code, and hand sync everything. We did that for years with the Nagras, but not any more. Or, for not a whole lot more money, say a couple grand, you could have the convenience of finding things by the numbers. You do still need to look carefully at the sticks, as the generators drift a little. Jam them together at the start of the day, and again when you come back from lunch.

 

-- J.S.

 

Thanks John,

 

Sorry to take so long to respond; I thought this thread had died out, until I checked it last night.

 

As always, you make some very intelligent observations, and I appreciate you taking the time to

answer.

 

Thanks to everyone who posted about this topic - I am in a much better position now to make an

informed decision.

 

I will definitely be pursing the timecode option, and my feeling is that a Sound Devices recorder

with a Denecke TC Slate is the way to go.

 

-Jerry Murrel

DP, Little Rock

Edited by Jerry Murrel
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....Here in 2010 it is absurd to be shooting anything without using timecode. To be spot-on with your audio and video or film buy a good audio recorder (Sound Devices, Zaxcom, etc) and jam timecode from the recorder to the camera while ALSO using a timecode slate or dumb slate....

 

Thanks Matthew,

 

I appreciate your advice ... Not what I was hoping to hear from a

monetary standpoint, but just what I needed to hear in regards to

post workflow, and saving headaches in the long run.

 

-Jerry Murrel

DP, Little Rock

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