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-   -   Filming a gunshot. audio question. (https://www.dvinfo.net/forum/all-things-audio/18524-filming-gunshot-audio-question.html)

Joe Gioielli December 18th, 2003 11:42 AM

Filming a gunshot. audio question.
 
I'm doing a film that has a close up of a .44 magnum being fired. Indoors.

Is this going to blow out the mic on my vx2000. If so, if I plug an adapter into the jack will that silence the audio. I can always add something on in post if I have to. But I would rather use the real sound if I can.

Federico Dib December 18th, 2003 11:55 AM

I donīt know about protecting the mic... Iīd like to hear that answer... as I might be doing something like this soon...

But I wouldnīt use the real sound... unless I was going for an ultra-reality style...
Iīve heard real shots... and they just donīt sound "real"... Maybe is because Iīm used to the Movie Shot sounds...

It also happens with punches.. in a short I woked... there was a fight scene were the coreography went wrong and one of the actors punched the other one in the jaw real hard... we had the real sound... and it was weak... I mean it sounded well enough for a jackass.. but for fiction... we had to do the foley way...

Rob Wilson December 18th, 2003 01:10 PM

Joe,

Plugging a plug into the external mic jack will electrically isolate the mic from the cam but will do nothing to protect it from the excessive SPL. I don't know if that will harm the mic element or not but suspect it would be the weak link, not the electronics it's connected to.

Stephen Schleicher December 18th, 2003 01:48 PM

Interestingly enough, depending on where you and your mic are possitioned around gunshot/cannon fire, the sound can be quite different.

Many years ago I had an LP (yes, a record) of the 1812 Ovature. At the end of the end of the recording, the distributors had a lengthy discussion of how they recorded the cannons and bells. They then played several different selections of the cannon fire placed a different places. It was pretty interesting to listen to, even as a wee tike.

Sadly, I have misplaced, lost, or otherwise can not find that original record.

Stephen Schleicher
www.mindspring.com/~schleicher

Joe Sacher December 18th, 2003 02:32 PM

I this type of situation (.44 Mag INDOORS) the over pressure is about as bad as it can get with a handgun. I have sealed mics with loosely wrapped plastic over foam to try to reduce the concussion and have not been able to get a realistic sounding gunshot with any method from too close. The best method I have come up with is to use a small piece of cardboard or similar in front of the mic, to take the brunt of the pressure. Then the sound is recorded from around the cardboard. Unless it is important to see the power of the .44 Mag, I would load it with lighter .44 Special rounds to reduce the pressure wave.

I'd also like to hear what techniques people use. I will be shooting some footage with AR-15s and pistols in the future and I wouldn't mind hearing better ways to do it.

Douglas Habib December 18th, 2003 02:57 PM

To an untrained ear, the "sound" of a .44mag vs .44spl vs .357 vs .38spl vs .45colt vs most other revolver loadings is not THAT significant from the same length barrel. Remember, I said UNTRAINED ear. How fine do you REALLY need to split this hair??

(Be aware that rifle "signatures" are more distinct, and unique to the particular firearm. More familiar ones (AR, AK, UZI, MP5, M2, etc.) DO require an authentic "sound" to be credible.)

Rob Belics December 18th, 2003 06:35 PM

Stephen,

I had that album, too! My brother might still have it and I play it over and over in my head (when I'm really bored). It was a great recording.

Mike Rehmus December 19th, 2003 07:39 PM

I purchased a Shure SM81C for loud impulse noises. It works well and I get good recordings of gunshots. And they all sound different.

Thanks to Hollywood and the Foley shops, a realistic sounding shot sounds weak. I always Foley the gunshots unless I'm taping automatic weapons. Even then I have to help the sound out in some manner. Fatten it up and add a little reverb seems to help.

www.sounddogs.com is the easy place to go for most sounds.

BTW, the 44 indoors cannot hold a candle to a 50 cal sniper rifle sound outdoors. Unless you were in a very small room maybe when the 44 was fired.

Jim Hendrie December 22nd, 2003 01:41 PM

Mike,

I have something to top that. My HK51 is a 9 inch .308 automatic rifle that has the blast of a .50 cal. I've done lots of shooting with it indoors! The rumble you feel from the concrete floor is...disconcerting!

At outdoor machinegun shoots, i often have .50 cal shooters move away from me because of the concussion. I've shot a little video of it using the built in mic of a consumer camera and it did ok. Would like to do more now that i have better equipment.

Jim

Robert Martens December 22nd, 2003 02:13 PM

"...lengthy discussion of how they recorded the cannons..."

And they play this in crowded concert halls? Wow! I thought classical music was boring...:D

Douglas Habib December 22nd, 2003 06:05 PM

An interesting tape of some "shoots" this past summer by a friend; we're expecting a "professional" recording for the Jan. meet. May be able to differentiate the differences between 9's, 223's, 308's, AK's, etc. if careful..... enjoy!

www.crinamex.com/julydbs.wmv

Rick Bravo December 22nd, 2003 09:53 PM

Joe,

First of all, as Federico stated, I would not use the real sound...at least not without first adulterating it a bit. Gunshots, in real life, are nowhere near what you hear in the movies and all-in-all, very boring. The only gunshot sfx that I have used, untouched, came from full load, theatrical, crimped blanks. Extremely loud and "rich" sounding as opposed to the weak crack of a live round. The only time the sound of a live round will excite you, is if it is being fired in your general direction!

The good thing about the .50, (and it is a BEAST), that Mike referred to, is that if it is being fired AT you, you don't have to worry about hearing it!

One of the things you can do to protect the mic from the overpressure, without losing quality, is to actually turn the mic around and point it away from the source. As you are shooting on a 2000, I would shoot a few que track shots with the camera pointing away from the weapon. Since you are indoors, there will be plenty of sound to capture and you can just sync in the sound in post. It would also help if your mic is set to attenuate the sound. You might also want to crank off a couple of test rounds and adjust the audio level manually prior to the actual shoot.

Don't worry about "trained" ears, although, if you are shooting different calibers of weapons in the same program, you don't want to use the same, exact "clip" for all of them, beleive it or not, it will sound very strange when you continuosly repeat the same shot. Play with different calibers, distances and aspect ratios when you lay the sound in.

One of the things that you can do in post, other than reverb, level changes, etc., is to lay in another audio track, edit in the same clip as your first track and then slide the second track by one, two or three frames off the original track. This will oftentimes give you a fuller, more "movielike" effect for your gunshot. This can be done in both linear and non-linear editing.

Also, and this is very important, make sure you pay attention to the audio "fall-off" at the end of a shot, gunshot, that is. If you cut out too soon or you don't overlap the fall-off with your incomming shot, it may sound weird.

If worse comes to worse, do what I do...play the music LOUD and hope no one notices!!!

Good luck and hope this helps.

Happy Holidays, RB.

Mike Rehmus December 23rd, 2003 12:03 AM

As the calibers get larger, it may be time to consider non-microphone transducers to capture the sounds.

I understand that 16" naval rifles will blow any microphone if it's anywhere near the rifle. Just in case you get an opportunity to record one.

Brian Huey January 22nd, 2004 04:30 AM

Wow I can't believe I missed a thread about gun shots that even had a Calvin & Hobbes quote in it! (nice work Robert)

What I've noticed from filming shoots (I'm originally from Alaska) is that the audio lacks the concussion wave effect you get when your alongside someone shooting. Not sure what frequency this happens at but the camcorder mics sure don't pick it up.

Anyone messed around with adding more of a lower end to the realist sound of the rifle? Maybe they should just add machineguns with blanks in theaters...

Douglas: When do we get to check out the January video of DBS?! You can check out my Alaska 'documentary' of what me and my friends do by going to my homepage, it has a shooting section in it, but it's quite a download at 20min/190mb (Divx required), I even used a similar song as you!

Cheers,
Brian

Rob Belics January 22nd, 2004 09:16 AM

You guys might look around and find out what they did for "Open Range". Probably the best sounds I've ever heard. Even my gun nut son was impressed. IIRC, they used the real thing for recording.


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