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Eric F Adams

Sound sync advice using film 0.01%

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Alright.  I will do my best to give background and explain concern. 

 

Shooting micro budget feature film on S16mm Arri SR2.  We have the Senn 416 that will go directly into a recorder/preamp.  I used a clapper and sync sound and film using FCP.  We do not have a sound guy on set (y'all kill me everytime with that comment) I was leaning towards the MixPre3 but a sound pro offered this advice below:

 

What you have to worry about is the sound and the speed shift due to shooting at 24.000FPS and transferring at 23.976 FPS so the AUDIO has to slow down by 0.01%.  The SD 702 can do that for you automatically.   If you use one of the cheeper recorders - your SYNC will be off.

 

He said he does not believe the MixPre3 will not do that pull down function. Would using the MixPre3 create a major problem for me?  Or is this pull down advice geared more towards music where it's one longer take? as oppose to manually syncing short takes for film?   I hope I made sense...all advice welcome.  Thanks. Eric.  

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Why are you shooting on film if your goal is to be an amateur filmmaker? 

 

If your goal is to be a professional filmmaker, you accomplish that by working with professionals. 

 

There are many reasons to hire an accomplished professional in any field.  One of the main ones is:  You have no clue what it is you don't know, and what you don't know will keep you among the ranks of wannabe amateurs.

 

 

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I won't address why you're shooting micro-budget on 16mm. Surely stock / lab / fxr costs are going to be significant. But that's your choice. (The last true low-budget indie I worked on that used film was in 2002... it was a very short piece, and the experienced videographer specifically wanted to shoot 35mm for the film experience.)

 

So let's address the pull-up/ pull-down:

 

This is necessary when 24 fps film gets transferred to video, which runs just a tiny bit slower than 30 fps. (The 24<>30 conversion introduces its own strangeness to motion, but at least that's integral so audio sample rates don't change. It's the 30 <> 29.97 fps that means you have to slow down the sound.)

 

1.  It's not absolutely necessary that you compensate. If you're doing short takes, you can sync each one. The drift at the end of 30 seconds will barely be noticeable. If you then have cuts so individual camera angles are even shorter, you can nudge to compensate. I've worked for major post houses where, in the era when spots were shot S16 and finished on NTSC, they didn't even bother with pull-down. 

 

2.  Using FCP can be an issue. Years ago, FCP had a known, uh, feature where it would apply .01% changes whether you wanted it to or not, depending on the drop-frame settings. (Drop frame rates have nothing to do with pulldown. The frames are the same length. It's how those equal-length frames are numbered that makes the difference.) Many productions were brought up short -- with complaints of 'your mix is out of sync' -- until we got a handle on this. I don't know if it still exists in the version you're using. I also don't know if other NLEs have had this problem. FWIW, just about every professional DAW and most audio editors have a function to compensate for pull-up or -down. 

 

3.  If you do need to compensate, you don't have to do it during production. You can do it in post, before editing.

 

4.  If you're going fully old-school, shooting film and then editing 16mm workprint against fullcoat, it's a don't-care. So long as the production track playback speed is the same as what you recorded when you transfer to fullcoat, you'll be fine.

 

 

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1 hour ago, Eric F Adams said:

 

Shooting micro budget feature film on S16mm Arri SR2.  We have the Senn 416 that will go directly into a recorder/preamp.

 

 

Hi Eric,

 

Just curious: How much have you budgeted for film stock, lab, etc? And what's the film's overall budget?

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I bet he's shooting film because it is instant art direction, a look.  It also imposes serious discipline on an indie crew, a good thing, usually.  When we recorded for film shoots in the telecine days we rolled with 30NDF TC, with the camera on 24fps.  If they want to shoot 23.98 fps then you can record the sound with just about any recorder with a decent clock, since there would be no pull down.  But, as always, test and confabulate with your peeps.

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1 minute ago, Jim Feeley said:

 

Hi Eric,

 

Just curious: How much have you budgeted for film stock, lab, etc? And what's the film's overall budget?

 

Hey Jim.  I don't have a set overall budget.  I wing it.  I shoot on weekends over period of a few/several months so I can space out my expenses. But it's several thousand.  Approx. total, included post expenses, will not be over 35,000.       

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8 hours ago, Eric F Adams said:

Thanks John for the reply.  Back to my question...Can the Mixpre3 slow it down by 01%?   

 

I don't know about he Mixpre3, but it is not 01%, it is .1% (one tenth of one percent. 

 

(And, I appreciate you taking my advice non-defensively. )

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The pull down for audio used to be done in telecine or transfer.   To change the record speed of your files you'd have to change the sample rate.  I do not recommend this at all, you can make all sorts of issues for yourself later on in post.  Anymore I strongly recommend a 1=1 shooting method, where the film frame rate of the camera is 23.98, and the audio is recorded at 48k with 23.98 TC. 

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6 hours ago, John Blankenship said:

 

I don't know about he Mixpre3, but it is not 01%, it is .01% (one tenth of one percent).

 

(And, I appreciate you taking my advice non-defensively. )

 

Hi John. I'm sure you meant 0.1% (.001x).

 

Eric, assuming the film will be transferred to video for editing, it will probably be pulled down .1%, to 23.976. So that the sound stays in sync during the pull down, it should be recorded at a sampling freq of 48.048 (.1% faster), so that when it is pulled down, it will be at the desired sampling freq of 48K.

However, it seems that the MixPre3 does not have 48.048 as an option, which is probably what your friend was trying to tell you.

 

 

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On 2/16/2018 at 6:03 PM, Philip Perkins said:

 Anymore I strongly recommend a 1=1 shooting method, where the film frame rate of the camera is 23.98, and the audio is recorded at 48k with 23.98 TC. 

 

agreed, although I'd recommend running camera at 24.000fps with telecine to 24.000fps and sound at 48khz with 24.000fps TC 

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