Doc Bernard
Indie Arms Member
You and me both.Of course, I REALLY want a Sound Devices recorder personally
Looking for better audio. Currently using H4N
- Thread starter Joe Stas
- Start date
henryqiu
Well-known member
1) First, the sound intensity (level) is not same as the sound pressure level, which is typically talked about in audio recording.
2) The example that 60db @ 10ft -> 15 db @ 20 ft -> 6.67db @ 30ft, is totally wrong, regardless whether you were talking about sound intensity or sound pressure level. Assuming these numbers are about sound pressures. Let's reverse the relation: 6.67db @ 30 ft -> 15db@20ft -> 60db@10ft -> 120@5ft -> roughly 180db @3or4 feet away, which is enough to kill humans instantly!!! If that were true, you would make a murderingly loud jet engine 3-4 feet away sound like whispering by running back from it about 20 feet away.
Doc Bernard
Indie Arms Member
LOL, take it up with the Master Handbook of Acoustics. That was a quote and using the math they show. Pg. 9, Chapter 1 "Fundamentals of Sound". Logarithmic math does not work like you describe. You cannot just reverse the numbers, and say, "see, the numbers are wrong." The sound source is the level it is. You cannot make it louder by getting closer to it, or going behind it. It flattens out to the level it is. But you can lose recorded intensity by getting further away.
Doubling a distance does not say what the initial at the source intensity was. It just states when you double the distance from the initial measured point, you have 1/4 of the first level.
Told you I was grabbing a book. LOL, you want that I link you to where you can get a copy? It is a very informative book. I have the 4th edition and graduated back in 2004, but I doubt sound changed that much between editions.
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Well, perhaps if I bought a NTG-2 or something similar with a shock mount I could mount it for run and gun if absolutely necessary. Then I could also use it on a boom if I have more time to set up a shot. I'm a tad worried that it might not be hot enough for the Zoom though.
Doc Bernard
Indie Arms Member
Alone, probably not. But put a mixer in between, then maybe. But that will be another piece of gear to wear. See why people are saying you cannot do both, and do it well?
Doc Bernard
Indie Arms Member
Seriously, I would focus on what was most important to you. One or the other is going to suffer. Choose what you want it to be. There is no other way under the circumstances you give. You don't want both to suffer.
henryqiu
Well-known member
I think you just need 1) a Rode VideoMic Pro, which retails at $229 from B&H, with 2) a good wind protector (about $30-40), plus 3) an extra 6 meter extension cable. With such a simple solution, you can:
- mount it on your 7D, as this mic is designed to be used that way. In this case, you can use H4n (instead of 7D) as the recorder, or use H4n to record a separate audio track or whatever else you want.
- hand hold your mic and walk up to your interviewee, or ask your interviewee to hand hold it for you (not preferable). This is when an extension cable may very well be required. In theory you could boom your mic. But if you are just one man band, I don't know how likely you want to boom a mic while controlling a DSLR (it can be done relatively easily if you use a conventional video camera).
- mount it on your h4n, and record whatever sound you like, for somewhat better results than recording directly into 7D. The results with H4n may or may be noticeably better than with 7D, because AGC does help when everything around you sounds loud and noisy. But the audio quality from a dedicated good recorder should be much more consistent.
You can achieve very usable results if your mic is close enough to the sound source, if you use a separate recorder like H4n, and if you monitor the recording like you do 7D's focusing and exposure.
I was planning to buy Rode VMP, because it's so damn simple to use. But eventually didn't go for it, as I believe it would most likely replace my NTG-3. I do like NTG-3 very much, though. My current recording chain is like many others do: NTG-3 -> MixPre-D -> Sony M10 -> (optionally) 7D. I can monitor both M10 and MixPre-D via MixPre-D, or just connect my headphones to M10 for simplicity. MixPre-D & Sony M10 are bagged most time, or both attached to a tripod leg. NTG-3 is more sensitive than NTG-2/VMP (NTG-2 and VMP are about the same, just different designs, and VMP is designed for on-camera use with a DSLR like 7D), and is about as durable as 7D. But in terms of audio quality, if used properly, I think they are all capable of giving you very usable results. Since you just need something for vimeo, they should be more than good enough.
Steve House
Veteran
What would I do? No one puts a gun to your head and forces you to roll camera today! Seriously, I would defer filming and make my first production activity finding someone to team up with who can share the workload. Trying to do it all yourself will likely produce a half-a**ed result and the last thing the world needs is another half-a**ed video - YouTube is plastered with 'em. If it's not been done right, it's not been done.
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Rick Burnett
Section Moderator
Or, can you do what the first production did that I worked on, they ADR'd all but ONE line in the film in post. And I did the ENTIRE sound mix for the film and it was one of the most painful things I have EVER done. We actually won a few awards at festivals for our sound work, but, I DO NOT RECOMMEND that path. We had to do it because I was not involved during filming, only post production, and the quality of the audio was horrible. They just didn't know (which is my problem with like 90% of independent films, they put little effort in the audio). I had to recreate EVERY sound, ever room tone, every noise. I had help with the foley and fight scenes, else, it wouldn't have ever gotten done!
For narrative work, this is at least an option. For documentary or interview style work, it just makes no sense at all to even think about that option.
I'd seriously put out a feeling for at least one other person to work with. A crew of two is really the minimal we EVER do, and we use this a lot. We both can do all jobs on set, though we prefer a minimum of 4 people generally.
Having good audio on your productions REALLY REALLY gives them a huge amount of polish!
For narrative work, this is at least an option. For documentary or interview style work, it just makes no sense at all to even think about that option.
I'd seriously put out a feeling for at least one other person to work with. A crew of two is really the minimal we EVER do, and we use this a lot. We both can do all jobs on set, though we prefer a minimum of 4 people generally.
Having good audio on your productions REALLY REALLY gives them a huge amount of polish!
Noiz2
Sound Ninja
Given that scenario I would actually recommend getting a Rode VideoMic Pro and installing Magic Lantern on the 7D so you can turn off the AGC. It's pretty directional and the stuff I have heard from it in ENG run and gun shooting is pretty good.
Go to Philip Blooms site and look/ listen to some of the crowd party stuff he shot with it and you can get a feel for what to expect.
One problem with your scenario is that it doesn't matter that much how good the equipment is on paper if you can't use it optimally in the field. If I were going to be be manning it I would not want a second piece of equipment I have to keep track of.
I would still say you need to find a buddy. It will make your life SO much easier.
Mitch.Kear
Well-known member
Yeah, I read the post from Noiz wrong and was only thinking in terms of level not loudness for some reason. Thanks GP for that website.
Doc Bernard
Indie Arms Member
Nice! That is almost identical to what the book says. And they use the same types of diagrams. The physics of sound can get intense, and that is why I got into it. I joked about the math, but the math is actually fun.
The coolest thing is how sound is so much like light in behavior.
And people wonder why trained/experienced audio guys get touchy when we are treated like glorified mic stands.:happy:
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Thanks for the helpful response. I'm certainly going to look at using a sound man when possible.
Unfortunately, as far as I'm aware, you can't use magic lantern on the 7D at the moment though. I suppose I can mount a rode and my H4N for these circumstances though and record direct into the H4N.
Noiz2
Sound Ninja
It looks like you may be right on that. Though there does seem to be some audio level setting in some menu? I don't have one so??? But it may be possible to defeat the AGC. The other thing is that for run and gun AGC may not be that much of an issue. You would have to do some tests, but in a constantly fairly loud environment it might not pump too much.
I wouldn't expect it to be OK but?
I wouldn't expect it to be OK but?
henryqiu
Well-known member
Currently there is no way (not even with a beta hack) to defeat the AGC on a 7D that is patched to the date, and there is no manual control over it.
However, there is a good reason why Canon decides to implement AGC in the first place, which actually means that typically there is no need to disable it if someone knowingly records audio into 7D. In other words, it's helpful many ways and can even be very helpful in certain scenarios, given that you can't manually control it. Of course, if you want quality audio, 7D is not much better than a cell phone being used as an audio recorder.
PS - there are inexpensive devices made to suppress AGC in 7D by sending inaudible audio to one of the 2 channels. Unlike what their descriptions say, they don't and can't disable 7D's AGC. They merely trick 7D into not engaging AGC, which is both good and bad. You effectively lose every bit of help from AGC, and 7D will no long try to prevent you from getting clipped audio.
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Mitch.Kear
Well-known member
Do you know what these devices actually are doing? I'm just curious. I wonder if there is a manual way to do this so you don't have to buy the device.
The device sends a tone, or noise (some are selectable between tone and noise), into one channel of the camera's audio input. That basically forces the ACG to clamp down and stay there, so it doesn't raise the gain at all when audio in the other channel gets quiet. Using one of these devices also means that you're stuck with only one record channel. There have also been issues with cross-talk between the noise/tone and the primary audio.