View Full Version : Onboard shotgun mic- mono or stereo?


Dave Allen
July 1st, 2013, 12:18 AM
Ok, I am sure I will cringe at this question 5 years from now...my new videocam comes with a compact shotgun mono mic. My old videocam had a larger built in stereo mic. For interviews I go Sennheiser wireless.

I usually keep the ambient background sound in the footage, and sometimes there are cars, motorcycles, ocean waves, and other such sounds, or maybe even a guy playing acoustic guitar.

So should I stow my mono shotgun and go stereo shotgun for ambient, and revert back to the mono shotgun for a person talking if a lav is not used?

Brian Drysdale
July 1st, 2013, 02:24 AM
All the sound recordists I know record everything mono, then record the ambient or atmos sound separately as stereo. All use MS Stereo rather than AB.

Brian P. Reynolds
July 1st, 2013, 05:41 AM
It depends on the intended use of the camera and how you intend to edit and use the recorded video......
Does your video edit software handle MS? many don't.... If it is recorded in MS does EVERY person who has access to the raw footage understand MS ...FULLY (not just sort of)
Do you feed it into a server based system like a Network News, if thats the case you might need to go with the mono FX mic. The network I do some work for uses a 4 audio channel audio setup in editing, Ch1 VO / dialogue , Ch2 Nat FX sound, Ch3 L music, Ch4 R music. (this is then mixed LIVE to air in this format) There is no room for stereo FX.

So really it depends on what you are doing and what the next process is.....

Gary Nattrass
July 1st, 2013, 05:47 AM
Personally I tend to use mono mic's most of the time and have AT875R as my main shotgun and a panasonic AJ-700P on my camera.

Stereo is usually recorded with off camera mic's and can consist of panned mono microphones but I do also have a sony ECM MS957 M/S mic which uses the M/S technique in it's capsule array but then outputs a more recording friendly A/B matrix-ed signal.

Stereo ambience and audio for adding in post tends to be recorded independent of camera audio and a lot of the time I just use stereo backgrounds from my library for addition to the soundscape in post.

John Willett
July 1st, 2013, 09:08 AM
Definitely mono.

A stereo mic. on a camera is a definite no-no (other than a very few very special occasions, used by an expert).

A stereo mic. on a camera causes a wobbly stereo image and the stereo image should be stable and then the camera moves around - the sound stays fixed until a scene change or a very obvious camera change (eg: changing from a front shot to a rear shot).

Richard Crowley
July 1st, 2013, 09:58 AM
A stereo mic. on a camera is a definite no-no...
A stereo mic. on a camera causes a wobbly stereo image ...

Indeed. ANY mic ON a camera will give you less than optimal (and often less than acceptable) results.

An ON camera mic is almost always TOO FAR AWAY from the sound source, and WAY TOO CLOSE to the noise from the camera and the operator.

Dave Allen
July 1st, 2013, 10:17 PM
The content will be Internet hosted, edited in FCPX. If a stereo mic on a camera is poor form, then why do so many prosumer Sony cams come with stereo mics? Why not just a cheaper mono mic?

Richard Crowley
July 1st, 2013, 10:38 PM
If a stereo mic on a camera is poor form, then why do so many prosumer Sony cams come with stereo mics? Why not just a cheaper mono mic?

Because those mic capsules cost less than US$1 each and there are two audio channels, so why not put two cheap capsules an inch apart and call them "stereo". The people who don't know the difference will be impressed, and the people who know better will write it off as cheap gimmicks.

How would YOU like to be the marketing manager when they say: We aren't going to put those cheap mics on the new model. They are nearly useless anyway, so let's market it as a "silent camera". People can plug in REAL mics if they are serious about sound.

Paul R Johnson
July 2nd, 2013, 01:50 AM
That's a bit severe Richard. Most of the cheap cameras have quite pleasant audio quality nowadays, even with dirt cheap, mass produced condenser elements. There's a fair bit of stereo width, and while of course it's possible to do better with even moderately priced external mics, as background it's quite usable. Very often I'd rather work with this than thin sounding short shotguns pointing like a torch as the camera moves. I understand where John is coming from, but I find the very weird sound of a mono strongly directional mic panning across the scene far more disturbing than the wider more gentle effect of doing it with a stereo mic. Worst case is sport, where with a crowd, or noisy items like motorcross bikes, you can be working at the long end of the lens, and suddenly hear things that are not in frame, like a new bike sound appearing and vanishing, but not being seen. With an on camera stereo mic, the up and down is much more gentle and easier to use. I guess it's preference isn't it?

Gary Nattrass
July 2nd, 2013, 01:54 AM
Problem is that certain people think that a mic is like a zoom on the camera and can pick up close sound but sadly the laws of physics do not allow that.

A stereo mic on a handycam may have it's uses for recording nice holiday video's but you just have to listen to all those clips on reality and clip based programmes to hear the effects of an on-board mic recording anything from 15-20 feet away.

As a sound engineer I would never in million years pan a mono mic to try and follow a picture on screen and even panning a camera with a mono mic fixed central will keep a static sound effect image, to do sound on sport properly required external mic's so you can set up a sound stage that compliments the pictures but keeps the imaging static so as not to distract the listener.

A camera mic can have it's uses in news etc and as a back-up but there are far better ways to record valid location sound with off camera mic's.

Dave Allen
July 2nd, 2013, 02:31 AM
I am sure a boom mic and a sound mixer guy would be ideal, but, my clients would never want to pay for that.

So lets say for the sake of argument it is going to be an onboard mic. Why go mono when there are stereo mics like the Sennheiser 418 which I hear is well regarded?

Would you prefer to use mono and have a somewhat hand held stereo recorder for ambient sounds?

The AF on my Sony/Zeiss lenses seems exceedingly quiet, so I don't think I will pick up cam sounds aside from maybe button switch clicks.

Gary Nattrass
July 2nd, 2013, 03:01 AM
With best respects I am sure when your clients sit in the edit suite and find that the camera mic regardless of being mono or stereo has made their material un-useable as you can't hear what is being said they will maybe think again about how useful a boom op could be.

You will be amazed how much clicking and servo noise will be picked up by a stereo shogun mounted on a camera a mono one will be better as you will now end up with distracting noises in the left or right channel.

An off board recorder will be better but if someone is speaking a mono microphone will be more focussed and less distracting than a stereo mic which will also pick up air con noise and any movement or noises that may not be actually relevant to the shot that is on screen.

If you really need stereo record a sep buzz or atmosphere track that can then be added and controlled in the edit but the key thing is to make the audio match your visuals and a stereo wide ambient recording of someone speaking in an echoey room with air con buzzing away will distract from the visuals if you are shooting someone in a tight or mid shot.

It is always easier to add any stereo content than take it away two weeks later when you hear it in the edit and the subject is back where they were filmed with little chance of a re-shoot.

Sabyasachi Patra
July 3rd, 2013, 11:05 AM
Some good advice given here. A mono shotgun microphone will reject a lot of off axis sound where as the stereo microphone on your camera will record all the camera sound, image stabilisation sound of your lens etc.

It is better to attach the stereo microphone to a standalone recorder and record the ambience.

Ty Ford
July 7th, 2013, 05:42 PM
The content will be Internet hosted, edited in FCPX. If a stereo mic on a camera is poor form, then why do so many prosumer Sony cams come with stereo mics? Why not just a cheaper mono mic?

Because they are not professional cameras.

Because cameras have two channels of audio

Because prosumers don't get audio.

Regards,

Ty Ford

John Willett
July 8th, 2013, 02:21 AM
Because they are not professional cameras.

Because cameras have two channels of audio

Because prosumers don't get audio.

Regards,

Ty Ford

LOL

Perfect !

Ty Ford
July 8th, 2013, 05:59 AM
Hello John,

Always good to see you out here. :)

I did notice an on-camera mic on a Baltimore TV station news camera on the 4th of July. He came to record sections of the Towson, MD July 4th Parade.

He has strapped a mic onto the camera handle and it looked like it had been there a while (as in years). This is called gathering b-roll with sound. The audio is secondary (or tertiary) and will probably not be used at all.

The camera was on sticks and the sound field was so loud when the bands came by that I'm pretty sure you couldn't hear and lens motors. He did go hand-held at least once, and threaded through the ranks of one of the bands, but again, usable audio was not the task.

Regards,

Ty Ford

PS: I was the MC of the parade. Here I am conversing with the Baltimore Orioles Bird Mascot (who never speaks!) And that's an SM58 on the stand.

Paul R Johnson
July 8th, 2013, 10:03 AM
On the consumers who think mics are magic comment. We were faced today with a sudden unexpected choir in the rehearsal for the dance show. No mention at all of a choir, and no time, with the rehearsal timed to the minute, and already behind. Best we could do was two handheld radiomics on low stands. We marked the floor, with glow tape, because they had to be set in the blackout. The stage crew had one each side of the stage, and in the blackout, they ran on, plonked them down and the sound op got ready to unmute them to route their audio to the video people.

The blackout at the end of the preceding dance came, the crew set them accurately on the marks and the lights went up to reveal the entire choir had missed their marks and lined up on the upstage ones, 16 feet upstage - and nowhere near the microphones. So the video people got no audio, and the audience didn't hear the kids either. They also completely missed the specially created puddle of light created especially for them, and stood almost in the dark.
I give up!

Ty Ford
July 8th, 2013, 10:46 AM
I love it when a plan come together! :)

Regards,

Ty Ford