How far must a Mic be from the 24-105mm IS?

H

hyalinejim

Well-known member
I'm going to be embarking on a fairly lengthy and involved documentary project that will require run and gun style shooting. For that reason, I'm considering buying the 24-105 IS because I like the range and, although I'll be shooting on a shoulder rig, I think I will also need IS.

My question is, how far from the camera must a shotgun mic (let's say the Rode SVM) be mounted so that it won't pick up the noise of the image stabilisation mechanism. Is a hot shoe mounted mic far enough away, or does it need to be extended even further away from the camera, using a shock mount or something similar?

A lot of the time I will be in a relatively noise environment. However, it's also quite likely that I will be doing some shooting in an empty room.

Many thanks in advance.
 
Two things:

1) Its important to note that a mic mounted to the top if a camera is useful for very little, if any, dialogue. It's there because it's slightly better than nothing at all - it's a fig leaf, essentially. If you are making a film you'll need to hire a production mixer/recordist. If your movie sounds bad it will also look bad. Be careful - don't try to do your own dental work.

2) Based on past experience, you will probably not believe what I just wrote and will do it anyway, adding yourself to the endless list of folks who make bad sounding movies, and who have learned that lesson the hard way!
 
Just stick to the question at hand, please.

How far away does a mic need to be not to pick up the IS noise of the 24-105?
 
I don't think the problem lies in how far the mic is away from the lens but how good of a shock mount you have. The reason the built in mic picks up the IS so bad is because it's practically connected right to it. If you have no hard connection to the camera body, you shouldn't pick up much. I'm assuming you have the kit 18-55, so just test it with that. Or just put your ear up to it and see how far away it needs to be before you hear it.

I think once you get a shotgun mic on a shock mount and on the hot shoe you shouldn't have to worry about the distance. The 24-105 will probably have quieter IS anyway seeing that it's a "L" lens. (Don't know that for a fact though)

(I agree with adanac's #1 comment though also.)
 
Thanks for that jcskeeter.

adanac, your reasoning is deficient.

Anyone else with any experiences? (on topic only, please)
 
Using a 70-200 f4L with the IS on and a Rode VideoMic I encountered no recording of the motor noise.

It is still not a very good way to record clean audio. I use mine for looks and a bit better source to match up my externally recorded audio to.
 
Great, thanks for that. From what I've read the 70-200 f4 is slightly noisier than the 24-105, so it's good to hear that you haven't found it to be a problem.
 
Don't freak out. You are absolutely welcome to shoot your whole movie with only a mic on top of your camera and I have no doubt you will. It has nothing to do with me so don't confuse me with it. It's a simple fact that it makes for poor sound which is why the show I'm on uses 10 lavs, 2 booms and two production mixers with with Sound Devices multi-tracks and NOT mics mounted on the three HDX900's we use. I know you disagree with that, which is your business (and your film will have the sound you want), your attempts to censor me and other forum members aside. Move forward and do good work! Good luck with your project.


hyalinejim said:
Thanks for that jcskeeter.

adanac, your reasoning is deficient.

Anyone else with any experiences? (on topic only, please)
Click to expand...
 
I agree that using camera-mounted mics is not the best - not even close - method.

But the OP said he is shooting a run-and-gun style documentary. The VideoMic is probably just to get acceptable audio to go with his shots, not necessarily to give a cinema sound. Documentaries and ENG are allowed to scrimp on some features that narrative films simply are not. When Dateline camera crews chase down some headline sleezeball who's in trouble for stealing people's identities, how many times do you see subtitles for that person's dialog?

We don't know enough about the OP's project to pass judgment on his methods. The best we can do is help with the immediate question.
 
Although I don't think I'll be chasing sleazeballs, jscottprice's post is on the money. The nature of the project is yet to be fully determined by the client, which will have implications for the ways in which audio can or should be recorded. The only thing I know for sure at the moment is that I need to be mobile, and so will need IS. Regardless of other audio inputs, I will be recording ambient sound from my point of view under some shooting circumstances, this much I do know, and hadn't found any info online that was pertinent to my question. I'm not sure why someone would assume it would be the only audio source.
 
That said- crap audio is crap audio. And putting the mic on the camera instead of less than a foot from the thing you want to record via a boom pole or even a lav will result in- you guessed it- crap audio. But go for it my friend. Some folks need to burn themselves to find out fire burns...

noah
 
I have asked a specific and delineated question. I'm not looking for an exposition of Audio 101. I got my answer so thanks to the posters who provided that info.

Nevertheless, I slightly appreciate all of your unsolicited concerns for the well-being of my project.
 
This response is totally beside the point but just an FYI re the 24-105 f4. I bought one thinking it was the perfect range and I could handle losing one stop from an f2.8, but that particular lens loses pretty much another full stop I assume to just light loss in the glass. Compared to the other Canon zooms it ought to be rated an 5.6. Its very slow. I tried a few of them so it wasn't aberration. Pretty much 2 stops slower than a 17-55 f 2.8. Too bad as I loved the range.
 
hyalinejim – there are 3 things that are going to affect your audio...

1) the vibrations from the IS on the lens passing through the plastic body into the mic
SOLUTION: make sure your mic is in a shock mount

2) the audible sound of the IS that you can hear
SOLUTION: make sure your mic is a shotgun and it is in front of the lens so its pickup pattern suppreses any audio from the lens - I would recommend at least 1 ft or more

3) the crap quality that DSLR's record audio.
You can have the most expensive gear in the world at optimum distance from the speakers mouth but if your recording setup is awful then what's the point? DSLR's are not designed for audio.
Of the canon line the t2i and 7d are cursed with AGC (auto gain control which boosts silence inducing hiss).
The 60d and 5dm2 have manual audio recording options which I have not tried but remember you are still relying on a DSLR mic preamp to get it to line level. I still wouldn't trust it.
SOLUTION: Your best bet is to run two system audio with a zoom audio recorder then sync in post. Or better still - switch to a camcorder. DSLR's for run and gun is about the worst combo I can think of.
 
Or better yet, hire a production mixer/recordist.

J Davis said:
hyalinejim – there are 3 things that are going to affect your audio...

1) the vibrations from the IS on the lens passing through the plastic body into the mic
SOLUTION: make sure your mic is in a shock mount

2) the audible sound of the IS that you can hear
SOLUTION: make sure your mic is a shotgun and it is in front of the lens so its pickup pattern suppreses any audio from the lens - I would recommend at least 1 ft or more

3) the crap quality that DSLR's record audio.
You can have the most expensive gear in the world at optimum distance from the speakers mouth but if your recording setup is awful then what's the point? DSLR's are not designed for audio.
Of the canon line the t2i and 7d are cursed with AGC (auto gain control which boosts silence inducing hiss).
The 60d and 5dm2 have manual audio recording options which I have not tried but remember you are still relying on a DSLR mic preamp to get it to line level. I still wouldn't trust it.
SOLUTION: Your best bet is to run two system audio with a zoom audio recorder then sync in post. Or better still - switch to a camcorder. DSLR's for run and gun is about the worst combo I can think of.
Click to expand...
 
not talking cinema sound, not even talking ENG sound (which is very good BTW)

have you sat and listened to audio that was recorded on a DSLR? Imagine a 30 yr old answering machine that is using a 30yr old tape ...
even a $300 DV camcorder from 10 yrs ago had better audio. We're talking major hissssss. And I'm not kidding

edit:
adanac I see you edited your post. Well the above sentences I wrote were in reference to your mentioning of cine or ENG sound
 
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