High production documentary interviews - Cardioid boom vs Lavalier - Help Appreciated

Tim Gray · February 21st, 2007, 09:57 AM

Quote:

Originally Posted by Brian Orser

Tim: Thank you too, for the idea of using both methods. I am planning on adopting it. As far as using a fixed boom, I repeat an earlier question: I was under the impression that, due to sound propagation laws, one must stay with the interviewer when using a boom. i.e. you have to follow their head even if they just move a few inches, as sound intensity drops so quickly with distance change. Is this true?

In my experience, unless you are interviewing a VERY active person, people just tend to sit in a chair, heads not moving too much. Especially if you as the interviewer are reasonably still since your interviewee will most likely be talking towards you (or the camera), not moving much, and a fixed boom will cover you in most situations.

This is an area that can separate the men from the boys in terms of mics. I would look for a good hyper (schoeps MK41, sennheiser MKH50, AKG 480 with hyper head, probably the oktava mic) that have very nice polar plots. If you have a mic that doesn't have a smooth off axis response (like most shotguns) when the source moves from directly beneath the mic, you will hear the tone of the source changing. If you've got one of the above mentioned mics, the tone of the source won't change, just the volume (a little). You could go with a cardioid which would give you a broader pattern which would help compensate for subject movement, but it's a broader pattern and won't reject other sounds as well (depending on the source of the sound).

As far as the laws of sound propagation and moving sources, the intensity of sound obeys the inverse square law. So, change the distance, and the intensity will drop like the square of the distance. With that in mind, picture your standard interviewing setup. Mic pointed towards the face/mouth region of your subject about 1 feet above their mouth (depending on framing). Person now looks to their side and says some lines, their mouth displaced about 3 inches from before. While the distance to the mic did change (sqrt(12^2 + 3^2) = 12.4 inches as opposed to 12 inches), it actually doesn't change that much and you won't get that much of a drop in volume due to mic placement. You are more likely to get a nasty sound in the case of a mic with bad off axis response (mentioned above) and/or a slight reduction in volume due to the polar pattern of the mic.

That being said, if the person all the sudden lies on the floor and is now 4-5 ft away from the mic, yes, you will have some problems. Try not to let your subjects do that.

Lastly, with respect to lavs, I actually have had more issues to due subject movement (in a seated interview situation) with them than with a boom. Say you clip the lav on the subject's chest on one side of their jacket. Now, when the subject looks to the side (away from the lab) and says something, you've seriously changed the distance and the person is now speaking AWAY from the mic. That is always noticeable to me. I also have issues with people scratching their face/arms/body, things brushing up against the lav, stomach noises, etc. Remember the inverse square law - while the lav is close to the subject's mouth, it is also pretty close to their lap (fidgetting with tissues, etc.), their arms and chest (clothes noises), their stomachs (indigestion) and so on.

Again, this is my experience.

Steve House · February 21st, 2007, 11:35 AM

Quote:

Originally Posted by Tim Gray

...
Lastly, with respect to lavs, I actually have had more issues to due subject movement (in a seated interview situation) with them than with a boom. ...

A good argument for using omni lavs instead of cardioids whenever possible.

Brian Orser · February 21st, 2007, 08:42 PM

Excellent info again. Thank you. I do have a question about the timecode on the recorders. I'm confused as to its usefulness - unless it's synced with the video timecode, I don't see how it will reference anything useful - unless of course the recorder and camera start rolling exactly simultaneously. I'm obviously missing something. Sorry. Whats the answer here...?

Steve: Thank you for the suggestions. I will look at those recorders. As far as a mixer, I was already planning on it, but am checking out Ty's post right after this. Thanks.

Michael: I will surely check out the Tascam. About the Countryman: if youre referring the mic Ty had on his face in the tutorial, I can't use that for obvious visual reasons, though I do think it gave some of the best sound. I'll see if I can get that Schoeps that everyone keeps mentioning - keep in mind I probably won't be buying most of this, but borrowing it from a professionals friends of mine, so I might not be able to get it. But I'll sure try. I am certainly planning on having a mixer and obviously monitoring the sound. Thanks for the tip on the preMix - I'll probably go for that.
I would be honored if you dropped by. If you like I'll keep you posted on our shoots up there. :)
I will certainly check out that book; I need advice on that as these subjects won't be easy ones.

Ian: As soon as I'm done with this phase and have gotten my gear we're going to do dozens of dry-runs on the lighting/sound/camera setup. I'll also check out the Edirol, and the rest of your suggestions. Thank you.

Tim: Thank you for the assurance. It will be very nice to settle for a fixed boom. The issue of lavalier rustle is precisely why we're using both grabbing methods (lav and boom hypercardioid) for coverage. I understand the insignificance of the movement of the interviewee. However, just out of curiosity (and in case it happens), if the person were to shift positions (cross legs etc) significantly, would one move the boom mid-interview, or wait till they finished their sentence, or interrupt them, or what? I can see that being a problem, though I will try to restrain them from lying down ;). Thank you for your help.

Steve: I'm confused - wouldn't that be a good argument for the opposite? Or do you mean omni lavs vs cardioid lavs?

Steve House · February 22nd, 2007, 06:27 AM

Yes, meant omni lavs instead of cardioid lavs when using lavs <grin> Cardioid lavs are most useful when their directivity is needed on a sound-reinforcement application where feedback from the house speakers can be a problem. But the downside of their directivity is that relatively minor movement from the talent or variations in the orientation of the mic clip can take them off-mic, with noticable changes in both level and tone. Because omnis pick up evenly from all directions, such movements are not as much a problem.

James Harring · February 22nd, 2007, 07:05 AM

With inexperienced crew, you may find they don't take proper steps to minimize handling of the boom (both in mic holder and in technique), resulting in noise. It can be tiring holding a boom arm still. Noise can come right thru if not properly isolated. While the boom will give better sound IMO, I'd backup with a lav.

Ian Savage · February 22nd, 2007, 07:58 AM

That is a very good point, especially handling noise, it's one thing it takes people a long time to learn, it may be worth considering buying an Ambient Floater, hell it's a handy thing for any boom op actually but for a beginner it can certainly make sure handling noise is kept to a minimum.

Tim Gray · February 22nd, 2007, 01:05 PM

Quote:

Originally Posted by Steve House

A good argument for using omni lavs instead of cardioids whenever possible.

Absolutely. Even with omni's though, you can still almost double the distance from mouth to mic with a simple shift of the head. Inverse square law (and indirect path from mouth to mic) are going to have a noticeable effect even with an omni - in my opinion and experience. Not that I've ever used cardiod lavs...

About the subject moving and when should you interrupt for repositioning. It depends on the situation, but my rule of thumb is if there is something going on on camera/set that is ruining a take, fix it as soon as possible. If you can stop the interview, do it and fix it; don't sit there sweating bullets. If you need to make a change that might result in the loss of some footage, do it as soon as you can, since you don't want to miss something REALLY important. Just my philosophy.

That being said, the times I've rigged up a hyper (MKH50) on a boom stand and done interviews, I've never really had to move the mic. Maybe the subjects were unusually sedate :)

Michael Nistler · February 22nd, 2007, 04:15 PM

Rehi Brian,

The Countryman E6 comes with a mini alligator clip that attaches to the respondent's clothing and the microphone tube, although you could get the B6 which is specifically designed to accomodate interviews (no long tube to the singer/speakers mouth). And if you're looking for a high-end lav, there's others that I'm sure will chime in here touting the Sanken COS-II http://www.sanken-mic.com/english/index.html

Enjoy, Michael

Brian Orser · February 23rd, 2007, 12:11 AM

Thank you guys again.

Steve: I understand. Gotcha.. :)

James: What is the source of this noise that you speak with poor boom operation? Also, what do you think of the third option of a fixed boom? Will it work, or will the sound intensity vary too much?

Tim: Though I am loath to interrupt people, your logic makes perfect sense. I'll keep that in mind. Thank you

Michael: Ok. Gotcha. I will certainly check out the Sanken. Thanks.

February 22nd, 2007, 06:27 AM	#19
Steve House Inner Circle Join Date: Mar 2005 Location: Hamilton, Ontario, Canada Posts: 5,742	Yes, meant omni lavs instead of cardioid lavs when using lavs <grin> Cardioid lavs are most useful when their directivity is needed on a sound-reinforcement application where feedback from the house speakers can be a problem. But the downside of their directivity is that relatively minor movement from the talent or variations in the orientation of the mic clip can take them off-mic, with noticable changes in both level and tone. Because omnis pick up evenly from all directions, such movements are not as much a problem. __________________ Good news, Cousins! This week's chocolate ration is 15 grams!

February 22nd, 2007, 07:05 AM	#20
James Harring Major Player Join Date: Aug 2006 Location: Tampa, FL Posts: 210	Boom With inexperienced crew, you may find they don't take proper steps to minimize handling of the boom (both in mic holder and in technique), resulting in noise. It can be tiring holding a boom arm still. Noise can come right thru if not properly isolated. While the boom will give better sound IMO, I'd backup with a lav.

February 22nd, 2007, 07:58 AM	#21
Ian Savage Regular Crew Join Date: Mar 2006 Location: England Posts: 88	. That is a very good point, especially handling noise, it's one thing it takes people a long time to learn, it may be worth considering buying an Ambient Floater, hell it's a handy thing for any boom op actually but for a beginner it can certainly make sure handling noise is kept to a minimum.

February 22nd, 2007, 04:15 PM	#23
Michael Nistler Major Player Join Date: Aug 2006 Location: Petaluma, CA Posts: 456	Countryman mic Rehi Brian, The Countryman E6 comes with a mini alligator clip that attaches to the respondent's clothing and the microphone tube, although you could get the B6 which is specifically designed to accomodate interviews (no long tube to the singer/speakers mouth). And if you're looking for a high-end lav, there's others that I'm sure will chime in here touting the Sanken COS-II http://www.sanken-mic.com/english/index.html Enjoy, Michael

February 21st, 2007, 08:42 PM	#18
Brian Orser Regular Crew Join Date: Jan 2007 Location: Santa Cruz, CA Posts: 87	Excellent info again. Thank you. I do have a question about the timecode on the recorders. I'm confused as to its usefulness - unless it's synced with the video timecode, I don't see how it will reference anything useful - unless of course the recorder and camera start rolling exactly simultaneously. I'm obviously missing something. Sorry. Whats the answer here...? Steve: Thank you for the suggestions. I will look at those recorders. As far as a mixer, I was already planning on it, but am checking out Ty's post right after this. Thanks. Michael: I will surely check out the Tascam. About the Countryman: if youre referring the mic Ty had on his face in the tutorial, I can't use that for obvious visual reasons, though I do think it gave some of the best sound. I'll see if I can get that Schoeps that everyone keeps mentioning - keep in mind I probably won't be buying most of this, but borrowing it from a professionals friends of mine, so I might not be able to get it. But I'll sure try. I am certainly planning on having a mixer and obviously monitoring the sound. Thanks for the tip on the preMix - I'll probably go for that. I would be honored if you dropped by. If you like I'll keep you posted on our shoots up there. :) I will certainly check out that book; I need advice on that as these subjects won't be easy ones. Ian: As soon as I'm done with this phase and have gotten my gear we're going to do dozens of dry-runs on the lighting/sound/camera setup. I'll also check out the Edirol, and the rest of your suggestions. Thank you. Tim: Thank you for the assurance. It will be very nice to settle for a fixed boom. The issue of lavalier rustle is precisely why we're using both grabbing methods (lav and boom hypercardioid) for coverage. I understand the insignificance of the movement of the interviewee. However, just out of curiosity (and in case it happens), if the person were to shift positions (cross legs etc) significantly, would one move the boom mid-interview, or wait till they finished their sentence, or interrupt them, or what? I can see that being a problem, though I will try to restrain them from lying down ;). Thank you for your help. Steve: I'm confused - wouldn't that be a good argument for the opposite? Or do you mean omni lavs vs cardioid lavs?

February 23rd, 2007, 12:11 AM	#24
Brian Orser Regular Crew Join Date: Jan 2007 Location: Santa Cruz, CA Posts: 87	Thank you guys again. Steve: I understand. Gotcha.. :) James: What is the source of this noise that you speak with poor boom operation? Also, what do you think of the third option of a fixed boom? Will it work, or will the sound intensity vary too much? Tim: Though I am loath to interrupt people, your logic makes perfect sense. I'll keep that in mind. Thank you Michael: Ok. Gotcha. I will certainly check out the Sanken. Thanks.