1D Mark IV sound recording issues

[aram535]

We just tried to do a 1080p with audio, the talent was wearing a Azden WLX-PRO VHF Wireless Lavalier Microphone System and monitoring via the Azden itself the sound was very good.

After the shoot, the sound level is extremely low with a loud hiss in the background.

Any ideas?

[skwirnmn]

Originally Posted by aram535

We just tried to do a 1080p with audio, the talent was wearing a Azden WLX-PRO VHF Wireless Lavalier Microphone System and monitoring via the Azden itself the sound was very good.

After the shoot, the sound level is extremely low with a loud hiss in the background.

Any ideas?

I have no experience with your particular mic, but often times, levels will sound adequate through headphones and are too low, or over modulated when you're reviewing footage/audio. watch your audio metering on your camera or mic.

[aram535]

According to Canon's Support the 1D Mark IV isn't actually considered a "Video" DSLR it has no sound leveling, or gain control. Their recommendations is the 7D, or 5D III for Video.

[ben_r_]

My recommendation is to get that audio capturing OFF the camera! Get a separate digital audio recording and sync in post. It is NOT hard to do.

[PM01]

You'll need a digital recorder that isn't part of the camera. Only way to do sound recording if you want it right. If you're critical, make sure the recorder has Time Code output. The one that I use is the Sound Devices 702T. Outstanding units.

Without Time Code, the frames of video will lose sync with the sound. The longer the video, the more chance of losing sync.

[aram535]

My scenes are usually 1-2 minutes. I was looking at going with a Zoom H4N. I'm know the Zoom can export out the "standard" audio formats but I'm not sure if it can do it with a time code.

[PM01]

Originally Posted by aram535

My scenes are usually 1-2 minutes. I was looking at going with a Zoom H4N. I'm know the Zoom can export out the "standard" audio formats but I'm not sure if it can do it with a time code.

The Zoom does not have time code. Only very high end models like the ones from Sound Devices have them. They're meant for production / indie work. I've looked at Marantz, Zoom, Tascam, Nagra and quite a few others but the Sound Devices "T" series are one of the few that will have the time code.

At 1 to 2 minutes, I don't think you'll have to worry.

[ben_r_]

Originally Posted by PM01

You'll need a digital recorder that isn't part of the camera. Only way to do sound recording if you want it right. If you're critical, make sure the recorder has Time Code output. The one that I use is the Sound Devices 702T. Outstanding units.

Without Time Code, the frames of video will lose sync with the sound. The longer the video, the more chance of losing sync.

Does the Mark IV even write its own TC? Even if it does Im sure its not jammable, so a time code capable recorder isnt going to do a bit of good unless using a TC smart slate or trying to feed the TC from the TC generator into one of the audio channels of the DSLR. But even this doesnt work accurately as the audio is usually a couple frames off from the video in DSLRs.

Also, timecode doesnt have anything to do with video and audio keeping in sync, thats dependent upon the frame rate and the sampling rate. TimeCode is just an embedded reference that only works if the both the video and audio files are accurately syncd. DSLRs are notorious for being very poor at dealing with TC which is why any professional shoots done with them use a smart slate to visually mark the frame with the TC value.

[aram535]

All good information -- thank you.

Just to update the original thread. My issue turned out to be quicktime driver/codec. It verified fine, played video fine, but on some file the audio was just getting cut out. I re-installed it, and it's working again.

EDIT: Sorry missed your response by crosspost-- no Mark IV does not have a TC. I would have to have a external system. Doesn't matter though with the short scenes I am not too worried about loosing sync.

[PM01]

Originally Posted by ben_r_

Does the Mark IV even write its own TC? Even if it does Im sure its not jammable, so a time code capable recorder isnt going to do a bit of good unless using a TC smart slate or trying to feed the TC from the TC generator into one of the audio channels of the DSLR. But even this doesnt work accurately as the audio is usually a couple frames off from the video in DSLRs.

Also, timecode doesnt have anything to do with video and audio keeping in sync, thats dependent upon the frame rate and the sampling rate. TimeCode is just an embedded reference that only works if the both the video and audio files are accurately syncd. DSLRs are notorious for being very poor at dealing with TC which is why any professional shoots done with them use a smart slate to visually mark the frame with the TC value.

M4 does not have it's own time code. 1Dx does though. But the 1Dx code isn't jammable but at least you'll have two clock codes that you can "line up" with, even though they are different readings. That is, the clock oscillators are much more accurate on the 1Dx and are temp compensated IIRC. Frame sizes should be, in theory, the same.

If you keep the clips short, I wouldn't worry too much about drifting. I was watching Vincent L's video on the 5D2 (hour long) and it really started to drift past the 15 minute mark. By 30 to 45 minutes, it was not watchable - looked like a bad dub job in the cheapo martial arts movies!

[videochicke]

There is a program called Plural Eyes that will sync all your clips.

[ChasWG]

And there is a free bit of software that Sound Devices put out that will help in all your resampling needs. The issue is that most hand held recorders default to 30fps. So if you are shooting a 24 fps project and your H4N or DR-40 are recording at thier default of 30 fps, you will have noticable drift after a fairly short time. About 2 minutes or less. My SD 552 has a built in 2 channel recorder and it too defaults to 30 fps, not 29.97 fps but a true 30fps unless I feed it with external TC, then it switches over to the frame rate of the incoming code. This is where most people's issues of sync drift come from. But with the SD's Wave Agent software, you can re-sample any .WAV or even mp3 file to the a correct sample rate/frame rate, (sound really doesn't have a frame rate, but that's how we say it so we all know what were talking about, other wise you have to write out a nasty mathmatical calculation to express the sample rate properly, so we say fps for sound too).

Do a Google search for Sound Devices Wave Agent and down load it. It's truely a very nice tool and so helpful. And its free.

And Ben is correct, having a TC recorder makes no real difference unless you can output that TC to a Smart Slate like a Denecke TS-1 or simular unit. And even then is it really needed when working with a DSLR. I say spend the $150 or so and get Plural Eyes rather than spending $1200 for TS-1 TC slate. Having a SD 702T as your sound recorder is great, but unless used to its full extend it is really not much better than having a Tascam DR-100 Mk II. The SD record will record a cleaner sound because of the higher quality preamps used as well as its much better internal electronics, but for most here its way overkill.