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Audio and Red

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Markus Rave

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I will be using a Sound Devices 744T togehter with my Red. We will shoot 24 fps. Now I stumble into the manual of the recording device stating that standard procedure when shooting film (and I guess they mean 24fps) is recording 30fps in the US and 25fps in Europe. I plan to connect the camera to the 744 through a timecode cable to sync them. It appears odd to try to do this when the cam runs 24 and the recorder runs 25fps. I would probably not go deeper into this but I remember an audio guy telling exactly the same thing. He stated it would be better in postpro to go this way.

Can anyone shed some light onto this issue?

Markus
 
You should be shooting the audio at the same frame rate as the camera. Otherwise how will you jam sync? It's possible to jam sync 29.97 audio to 23.98 picture with the RED ONE but that's about it. Do some tests and follow them through to the end of post. It's not something that fixes itself but it's easy once you set it up properly.

Noah
 
Cross jam the two, there's an option in the Timecode menu to do this between 23.976 and 29.97 and vice versa. Have a read through the manual for specific settings to achieve this, then test before the shoot (including going through the post chain to make sure your editing software can line it all up again with out problems).

HTH

Paul
 
If you are shooting at 24 (23.98) then record the audio at 29.97 in the 744T... You could also test recording at 23.98 in the 744T as well.
 
Jon Frost said:
If you are shooting at 24 (23.98) then record the audio at 29.97 in the 744T... You could also test recording at 23.98 in the 744T as well.
Click to expand...


exactamundo- either of those will serve you in post.

Noah
 
Why would you NOT want to record audio at the same frame rate as the video. . . i.e., 23.98 in this case.

Stephen
 
Stephen,

that exactly would be my question. But I am not a postpro guy and so I just put on what I heard to make sure I am doing the right thing. For me I would put both camera and 744 on 24fps an go. But there seems to be more about it. So I ask.
Since I am in Germany I understood camera 24fps, audio 25fps because of postpro reasons.

Stephen Pruitt said:
Why would you NOT want to record audio at the same frame rate as the video. . . i.e., 23.98 in this case.

Stephen
Click to expand...
 
Markus Rave said:
Stephen,

that exactly would be my question. But I am not a postpro guy and so I just put on what I heard to make sure I am doing the right thing. For me I would put both camera and 744 on 24fps an go. But there seems to be more about it. So I ask.
Since I am in Germany I understood camera 24fps, audio 25fps because of postpro reasons.
Click to expand...

If you read through the manual of the Red it does note that 24 fps refers to 23.98 and 30 fps refers to 29.97. I wouldn't think that using 25 fps on the recorder would be any good unless you were shooting PAL. I would stick with either 23.98 or 29.97. 29.97 being the safest as it seems to be the most versatile. And for ultimate safety use the clapsticks for every shot. Your post dept. will thank you if there is a problem.

Jason Hemmerlin
 
Stephen Pruitt said:
Why would you NOT want to record audio at the same frame rate as the video. . . i.e., 23.98 in this case.

Stephen
Click to expand...

The reason being is that :

A: Timecode is a camera reference. The audio is not recorded based on the frame rate like the image is. The Audio is recorded based on the sample rate and bit depth. The Frame rate is there as a way to help sync the two up. Sample is to Audio as Frame is to the Moving Image. If you ever get the chance to go to a Professional recording studio that is recording a band look at how the timeline gets broken down. You won't see timecode like you would in film or video. It'll get broken down into samples not frames.

Most people think the frame rate is an audio thing as for sometime now most recorders have had more settings for timecode on them then cameras did, but that was only because we had to be able to convert from Film to Video or From NTSC to PAL.

J. Hemmerlin
 
Ditto on the slate usage. If you follow the film style of shooting, you are building in enough preroll for post production. Your editor with bless you a thousand times over...

"Sound Ready/Camera Ready" (Camera and sound hit Record) - 3 count

"Rolling" - 3 count

"Slate (or Marker)" preferably with the Scene/Take numbers read aloud - 5 count

"Action"

" Cut" - and wait a 3-5 count before stopping tape/film/audio

I just used this system on a short and it really paid dividends in post.
 
OK, the reason you would want to record your audio at 25fps, is if your post is being done in pal, after the red footage is converted to pal then the audio will be synced at 25fps.

If you are syncing on a hd system at true 24 or 23.98, then your audio rates should be: red at true 24p audio at 30fpsnd, red at 23.98 audio at 23.98 or 29.97.

if you are shooting at true 24,then don't sync the camera tc to the 744t, use a tc slate jammed from your 744 and use that as your tc reference. if you a shooting at 23.98 then you can connect a cable from the red to the 744 at either 23.98ndf or 29.97ndf, or you can get a sync box jam the box at 23.98ndf from the 744 and connect it to the tc input on the red. make sure you have a timecode cable that is wired for input, it is opposite of the time code cable you would use to jam the slate from the 744t.

there are many workflows with working with the red or any HD camera, it is really important to no what system you are going to be using to sync and edit the footage. that will determine what audio frame rate you should be at.
 
rwoolfson said:
there are many workflows with working with the red or any HD camera, it is really important to no what system you are going to be using to sync and edit the footage. that will determine what audio frame rate you should be at.
Click to expand...

This in mind I was asking my audio guy and he always used 25fps for TV feature. Syncing that to the 744T means staying true at all times. I will use a slate and stay true to my own standards I guess. But I will also check with the sound studio and will post their 2ct since it seems to be open in workflow as Red is itself.

Sometimes choice should be damned :-)
 
Yes and no. Either way there is the possibility for the need for conversion. If you set the red to 23.976 and plan to edit the same, you might as well record the audio with the same timecode and then everything is plug and play.

If you are shooting on the red at 23.976 and plan to finish in 29.97 for DVD's or such then yes maybe record at 29.97.

Personally if you can give your audio the matching timecode to your video I would. It gets you into the edit faster and they can then be converted together if you need a new timebase.
 
Alexander: If you are shooting sync sound, think of it this way: you are synching the audio recorder to the camera. You are NOT synching the audio recorder to the edit system.

So to sum it up, if you are shooting synch sound, your audio timecode should be the same as the RED's. Otherwise it is MUCH less useful for synching. This is true for any camera/audio recorder combination.

If your camera is set to 23.976, and you are recording synch sound, your audio recording should use 23.976 timecode as well. If you are recording dropframe on the camera, you should record dropframe on the audio device.

With the right tools and knowledge, you can make anything work, but doing what I've just said will save you headaches. (Anybody here old enough to remember cross-reference resolving?)

J.Eric: If the synch sound matches the picture, then even if there is a need to convert, you are better off -- because both sources will go through the same conversion and you are less likely to end up with synch problems related to some random difference in the conversion.
 
It is really a post question. some post workflows require that you work at 29.97, so 23.98 would be a bad choice if post says so. If post doesn't object, then both camera and audio set to 23.98 would be fine.

23.98 = 23.976

It **almost** doesn't matter, as 29.97 and 23.98 are exactly the same speed and the metadata tc header could actually be swapped between each other in post anyways.
 
D Fuller said:
J.Eric: If the synch sound matches the picture, then even if there is a need to convert, you are better off -- because both sources will go through the same conversion and you are less likely to end up with synch problems related to some random difference in the conversion.
Click to expand...

Yes. I suppose I should have elaborated because that is exactly what I was driving at.
 
Tom: Sorry, but the original question is NOT a post question.

Sound is being recorded in sync with the camera. Sync sound TC should always be the same as the camera TC, otherwise it does not provide constant sync reference.

The post question is whether the camera should be at 29.97 or 23.9876 (or 25 or 30 or whatever). If the camera is right for post, the audio will be right as well.
 
D Fuller said:
Tom: Sorry, but the original question is NOT a post question.

Sound is being recorded in sync with the camera. Sync sound TC should always be the same as the camera TC, otherwise it does not provide constant sync reference.

The post question is whether the camera should be at 29.97 or 23.9876 (or 25 or 30 or whatever). If the camera is right for post, the audio will be right as well.
Click to expand...

sort of yes and no. 23.976 and 29.97 are the exact same speed, or with the audio master clock set at 48KHz. 24 or 30 require a 0.1% pullup so the clock actually runs at 48.048KHz in these instances. many post houses run a workflow that requires the audio timecode metadata to be at 29.97, even if the camera frame rate is 23.976. so the most correct setting generally is to crossjam the camera to the audio recorder or master clock (such as a lockit box) with audio at 29.97 and the camera at 23.976 as this will result in fewer callbacks from various post houses and eliminate a transcoding step for them. conceptually, it would make more sense to run both the recorder and the camera at 23.976, but I'm just saying that this will sometimes result in some sort of translation issue with someone "up there" if you do that. one of the things you don't want to do is to set the recorder to 24 or 30 fps AND apply a 0.1% pullup, as this will result in audio that is next to useless. if I get it approved ahead of time with post, or I personally know the editor and his workflow, or I'm editing it (non-professional projects), I'm with you, I'll tend to set the recorder and camera to the same exact framerates. newer houses that have completely modern setups, generally won't have issues with the whole 23.976 vs 29.97 "thing" as they could run either way, but it is the houses that have been around for awhile... i.e. those that are well established, that might not be so agile, because of legacy workflows.

(not being a post person myself, I don't understand the intricacies of this distinction, but if I had to venture a guess, 23.976 projects are actually run through at 29.97 but with a telecine process applied? - someone with an authoritative answer want to chime in? I just know what is standard practice amongst audio mixers / recordists)
 
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