DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Canon EOS Full Frame for HD (https://www.dvinfo.net/forum/canon-eos-full-frame-hd/)
-   -   another 5d audio question (https://www.dvinfo.net/forum/canon-eos-full-frame-hd/487348-another-5d-audio-question.html)

Bruce S. Yarock November 11th, 2010 05:23 AM

another 5d audio question
 
I have 2 7d's and when I need quality audio, I record to a Tascam dr 100. I have a job on Friday for a guy who just bought a 5d, has no idea how to use it, and wants me to do some interviews. I offered to use my set up, but he insists on using his camera, with a wireless directly into the camera. I've never dealt with the audio on a 5d, so here are my questions:

1- I assume you need to go from the wireless into some kind of mixer first, right?

2- Do the new 5d's come without auto gain control, or do you have to download the firmare to defeat agc?

3- Is there a headphone jack on the 5d? How would you monitor audio going into the camera?

Another option if he insists on on camera audio, is run the wireless into my Tascam, then run a step down cable into the 5d from the Tascam.

Any help will be appreciated.
Thanks
Bruce Yarock

David W. Taylor November 11th, 2010 07:20 AM

The Canon 5D2 is notorious for having a 'gross' Automatic Gain Control on the audio.
However the last but one release of firmware for the 5DMk2, firmware 2.0.4 provides manual audio control that defeats the AGC. (I've never used the last firmware that came from Canon).

So having selected 'manual audio', you can dial down the audio input gain, but it's still too hot for any form of 'line level input'.
I therefore use Tramm's Magic Lantern hack which does work with 2.0.4 firmware, to provide a better set of audio controls on the 5D2.

In Magic Lantern you can set the analogue input to '0'. This equates to about -20dB which allows, in my case the 'domestic line level' coming out of my Edirol R-44 mixer to give a 'unity gain' when fed into the 5D2. I say 'domestic line level...that's not the 'professional line level' of -4dB of course.
So say a peak of -6dBfs on the R-44 gives -6dBfs on the 5D2. It'll sound OK on the 5D2, but it'll never be as clean as on the R-44 but it's very usuable.

So in your case I'd:

1: Install Magic Lantern firmware...you put it on each of your CF cards and remember that have to select it everytime you switch on the camera. It just becomes routine though...''going to record, OK I'll just load ML!''
Feed the radio mic or mixer -20db line level output ( say the 'headphone output'?) back into the stereo mic mini jack on the camera.

However after downloading ML to your computer you'll need to tweak the 'config text' file so you have 0dB for the analogue and digital audio gains before saving that 'config' file.
You're getting the camera to not add any amplification to your signal. ML also shows audio meters on the top of the live view screen, something Canon never implemented in their 2.0.4 firmware.

ML is stable and perfectly safe, but occasionally it seems to freeze on loading in the camera and doesn't show the 'live view' screeen as it should. If that happens I know that I just need to persist with it ...it'll come good. ML does take a few extra seconds to load each time the camera has been switched off which I find bareable in order to get good audio on the camera.

ML also allows an audio output headphone feed, but I don't use that as I always have the R-44 as my audio master anyway, however you have to go back to the Canon firmware to hear audio from the small built in speaker I'm afraid.

David
Postfade Sound

Bill Pryor November 11th, 2010 08:37 AM

The 5DMKII gives you manual gain now and it works fine, but it's limited since you can't adjust it after leaving the menu mode.

The safest thing to do is your last option. Run audio to your recorder, then using a pad cable to the 5D. You can get the cable for $45 from DVCreators.net.

The only way to monitor out of the 5D is to use the AV cable. But that turns off the viewfinder anytime the AV cable is plugged in.

Here's what I do. First, I always double record--audio to my Zoom H4N and to the camera. It's foolish to trust your location sound to the cheesy little mini jack.

Second, I calibrate the camera's audio to the recorder's, similar to what you'd do with a mixer. I put some -12db tone onto the recorder's SD card. Then I play that to the camera, via the pad cable and adjust the camera's manual gain so I get -12db there. You can't see the meters when recording because they are only available in the menu. So you go into the menu, switch to manual gain and set the meters so you get -12db when it's playing out of the recorder. Then in theory the camera will record what the recorder is getting.

But then how do you monitor from your recorder, since (on the Zoom anyway) the line out is also the headphone jack? If your Tascam has a separate line out, then no problem, but I got a Y-adapter to plug into the recorder output. So my headphone goes to one side of the Y and the audio to the camera goes to the other side.

Now, here's where you can screw up: Make sure you set your -12 db tone on the camera's gain when the Y adapter is in place. If you calibrate the camera to the recorder without the Y adapter, it will be way off when you use the adapter. Make sure the Y adapter is hooked up when you do that calibration.

Sounds tricky but it works fine, and if something happens to camera sound, you're covered with your recorder. The bad part is that you're monitoring what's coming out of the recorder, not what's going into the camera. Since it's calibrated it "should" be OK, but we all know what that means. Generally it will be OK, but there's that little mini jack and those are notorious for failure. It's easy to knock the pad cable out when moving around. So you always want to double record.

Having said all that, I did all of the above on a recent shoot and the camera sound was surprisingly good. Not as good as the Zoom, but nobody would notice the difference unless you do a side by side comparison.

The other alternative is for the guy to spend $450 on the Beachtek box that takes XLR in, provides the right output to the camera and lets you monitor. But again you're monitoring before the camera gets the audio, and there's no backup if the mini cable fails. So it's much better to always double record.

I guess there's still one more alternative--just go from the wireless direct to the camera, set an approximate level, start shooting and hope the sound doesn't vary too much and take it on faith that it will work. Assuming the wireless will give you a mic level output. But check every take carefully.

Tony Davies-Patrick November 11th, 2010 10:18 AM

I use the 5D internal recorder and a seperate H4 Zoom at the same time. I simply set the 5D recording levels Manually, and just let it roll. At the same time I'll record sound through the Zoom's onboard Stereo mic and monitor with headphones connected to the Zoom, or if I'm recording through a Sony WRT/WRR Radio mic that is receiving two seperate signals from two lapel mics connected to the Zoom via XLR leads, I'll connect the headphones to the Sony WRR itself.
During post editing, the sound directly from the 5D is mainly used as a guide to line up the seperate sound files from the Zoom, then I simply mute the 5D sound and up the sound levels of the Zoom file to required levels.

The stereo sound straight from the 5D body is terrible when filmed outdoors and tends to catch every movement of wind or lens adjustment, so I almost always use the Zoom or Sony recordings; but there are odd occasions when something has gone drastically wrong with the main Zoom or Sony recordings and the 5D onboard sound has come to the rescue. This has only been on calm, windless days and when the subject being filmed is very close to the onboard mic.

Peer Landa November 11th, 2010 08:48 PM

Quote:

Originally Posted by Bruce S. Yarock (Post 1587002)
he insists on using his camera, with a wireless directly into the camera. I've never dealt with the audio on a 5d, so here are my questions:
1- I assume you need to go from the wireless into some kind of mixer first, right?
2- Do the new 5d's come without auto gain control, or do you have to download the firmare to defeat agc?
3- Is there a headphone jack on the 5d? How would you monitor audio going into the camera?

I run a mono wireless Lav straight into the camera, using a Sennheiser G3 -- i.e., no mixer. And then for the camera's second channel I use a small on-camera shotgun mic (made by Ambient) which is also fed directly into the camera. In addition to this, I usually use a 2nd recoding device also mounted on the camera (but of course freewheeling it since the 5D has no SMPTE) -- this unit is usually a Sony D1 or a D50.

Here's a picture of my setup:

Mike Watson November 12th, 2010 01:05 AM

Quote:

Originally Posted by Bill Pryor (Post 1587051)
I guess there's still one more alternative--just go from the wireless direct to the camera, set an approximate level, start shooting and hope the sound doesn't vary too much and take it on faith that it will work. Assuming the wireless will give you a mic level output. But check every take carefully.

I have done this, it works, and it sounds good (like was said before, it's no H4n, but it's usable). I'm not proud of it, but sometimes you just have to make it happen with what you've got.

Bill Pryor November 12th, 2010 09:26 AM

True, you can always work with whatever you have to work with under the circumstances, but shooting sound without monitoring it is like shooting video without looking through the viewfinder.

Greg Kiger November 12th, 2010 08:32 PM

I use a Zoom unit. Plug the mic in, watch the meter for levels, listen via the headphones. I leave the 5d auto gain on. In post i use PluralEyes software with FCP to line up the good audio from the zoom unit with my 5dM2 "reference audio'. Once they are lined up, which with PluralEyes is pretty darn fast, just delete the 5d audio and you are left with nice quality audio perfectly synced to nice quality video.

Mike Watson November 13th, 2010 01:42 AM

Quote:

Originally Posted by Bill Pryor (Post 1587390)
True, you can always work with whatever you have to work with under the circumstances, but shooting sound without monitoring it is like shooting video without looking through the viewfinder.

To be fair, it's like looking through the viewfinder, setting up the shot, setting the focus, setting the iris, setting the framing... then looking away and pressing record. I'm not saying it's a great method, I'm not even recommending it. But to make it sound like tossing a blind guy the keys to your Mercedes... it's not.

Peer Landa November 14th, 2010 01:48 PM

Quote:

Originally Posted by Bill Pryor (Post 1587390)
True, you can always work with whatever you have to work with under the circumstances, but shooting sound without monitoring it is like shooting video without looking through the viewfinder.

Quote:

Originally Posted by Mike Watson (Post 1587610)
To be fair, it's like looking through the viewfinder, setting up the shot, setting the focus, setting the iris, setting the framing... then looking away and pressing record. I'm not saying it's a great method, I'm not even recommending it. But to make it sound like tossing a blind guy the keys to your Mercedes... it's not.

I agree with Mike -- if you have set up your audio correctly (i.e., practiced and rehearsed your audio prior to shooting) it should be sufficient to just make sure the signal strength is within approx ~9dB below clipping. Of course, having access to an entire crew (including someone who monitors your audio) would be the perfect scenario. But I guess most of us 5D2'ers usually run a one-man-show and hence need to rely on our preparations (and a little bit of the good ol' leap-of-faith ;^)

-- peer


All times are GMT -6. The time now is 07:20 PM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network