I usually shoot video with my 24-105 F4L but shot some acoustic music with my 70-200 F4L. Even though it was on a tripod I didn't turn off the stabilizer (IS) for the shoot. I'd literally never noticed noise from it before in my videos but usually didn't use that lens except for louder rock music. I used a RODE SVM mic attached to the hotshoe of the camera. I knew that stabilizer noise can be a problem, but the 24-105 w/ RODE SVM, it had never been a problem.

That said, how do i remove that constant low gear noise from the audio? I have Sony Vegas Studio 10 HD with a lot of different audio FXs including the NewBlue tools. Is there a way to somehow "white noise" balnce this out of the clip. I'm not the sound dude but sure hope there's a solution....

TIA much
Harry

If it's a constant noise, like say a fan might be, then a noise reduction plugin like Sony Noise Reduction or Izotrope's Rx can reduce it. If it's intermittent, lots 'o luck.

Steve,

It's a constant noise throughout the audio. Being fairly ignorant of how to adjust sound, What settings should i be mucking with with either of these two products. Preference of one over the other? I have the Sony and NewBlue FX sound FXs but I really don't know what I'm doing once I get them loaded to set the settings.

I have not used Izotrope's Rx, but frequently use Sony's NR-2 plug-in.
I find it better to sometimes use two processes instead of one. For instance, apply two processes of 8dB instead of one of 16dB to minimize artifacts, re-capturing a fresh 'noiseprint' on the second pass.
For NR-2:

Select a 'noise print' . (a few milliseconds of just the noise you wish to attenuate, for instance, room tone or when no ones talking.
- open NR-2.
- select the Noiseprint' button.
- check mark the 'Capture' box.
- select the 'Preview' button. (a noise print waveform graphic should appear after a few seconds)
- select the 'General ' button and adj, other parameters if desired.
- right-click in blank area under the 'Bybass' and 'Realtime' checkboxes in the General or Noiseprint' windows.
- from the pull-down menu: click "Select all data".
- click OK.

Constant as in a continuous sort of buzzing or continuous as in a burst of noise that keeps occurring every second (more or less) throughout the recording?

I've had very good luck with Izotope Rx and it's the frst thing I try when there's a problem. Sound Soap has worked well for me as well.

Basically the workflow is as Rick pointed out ie select noise and then filter it out. I used to make several light passes, but the folks at Izotope recommended a single stronger pass - either way it's a try and stand back operation - the trick is to find the setting where you get good noise reduction without damaging the material.

Haven't tried the Sony package so can't comment.

Audacity (free) has a spectrum analyzer built in that will visualize not just amplitude by time as a waveform will, but add in frequency as well (time on X, frequency on Y and Amplitude show by color). This allows you to visualize your sound and see if the noise sticks to a specific frequency which you can then "notch" out with an EQ set to specifically that frequency... the specific technique is to:

- pull up the filter with the sound looping (preview)
- use a High "Q" value (the frequency width of the effect) to affect as little as possible
- crank the amplitude/volume on the filter as high as it will go
- scrub through the frequency range until just the sound you want to remove gets really loud
- drop the amplitude, and twiddle the "Q" slightly to spread out the notch just a little bit and the sound will be magically gone...

Caveat: if there are other sounds that occur at that same frequency, they'll be gone as well.

The client is in a big rush for another video that I used the 24-105 F4L on and yes I used IS on it too though It was much less noticeable but sounded kind of like a low air conditioner like noise. I could get rid of that noise by applying NewBlue Polish and Cleaner but the resultant sound has the voice spounding like we were shooting in a tunnel.

From now on gonna have my mic so far off the camera!! I swear. And or cut the IS off.

I opened Sound Forge Audio Studio and could not see where the smaple and remove tool was right off but didn't have much time to mess with it. The "Audio Studio" version of Sound Forge may not have it.

Now to try to counteract the tunnel sound.....thanks for all the input

"The "Audio Studio" version of Sound Forge may not have it."

That's right Harry, Sound Forge Audio Studio does not come with the Noise Reduction-2.0 plug-in.

The "Tunnel" sound can be an indication that you've been too aggressive with the noise reduction. It's really a balancing act to get the noise level low enough that it isn't distracting (not zero, just not particularly noticeable) while minimizing damage to the rest of the audio. Getting rid of the tunnel sound might be best accomplished by starting over and being less aggressive (if that's possible in New Blue - I don't have it so don't know)

Hard to tell without hearing the clip but if I had to guess, I'd guess that unlike the low frequency AC rumble, the noise would be at a higher frequency ie lay right on top of spoken dialogue, frequency wise, which might make it harder to remove without collteral damage.

How long is the clip - can you post it somewhere? If it isn't too huge I'd be happy to take a shot at it with Izotope and see what happens.

It's actually two clips in the production each being about a minute long. And the noise is really kinda noticable mostly when it stops if that makes any sense.

I guess it's kinda like the smoothing I do in retouching photos - too much and you have plastic people.

When I get to the house I might take you up on that if its not too much.

Makes a lot of sense

Couple of minutes is no big deal - happy to do it partly to solve your problem and partly to satisfy my own curiosity about how well Izotope will perform on it.

I may have to go to LA tomorrow but should be around all day today.

I may send you one from the bad boy lens that started this whole thread. It's super noticeaable on that one. Heck if this works I'll be buying that app myself!!

I wouldn't mind giving it a go as well... post a wav or aiff for us to poke at... we'll see which technique/combination works best :)

Here is a screen shot of the spectrum in Audacity (IMHO, STP's is better looking, but this is functional). The sound portrayed is a baritone male delivering dialog:

This view is accessed in the track dropdown (here labelled "Dialog" - the name of the file I'm working on), set it to "Spectrum".

Your A/C should show up as a distinct line at a specific frequency. This will give you an idea of how pervasive the sound is before attacking it.

I wouldn't mind giving it a go as well... post a wav or aiff for us to poke at... we'll see which technique/combination works best :)

Welp I tried to upload the wav but it's 45M which 8M is all I can attach here. I did load it into Audacity and set it to spectrum and it was an acid trip flashback.......could make any sense out of the sprectrum setting.....

So here attached is a short first section of the audio with the 70-200 IS stabilizer noise. Sounds kinda like a geiger counter noise.

OK, the noise is relatively high frequency, and overlaps the guitar and ambiance fairly heavily... here's my results both with an EQ and a Noise Reduction filter in STP:

Thanks Cole

James in AZ tried too but the audio is doomed i'm afraid. the client is satisfied with the photographs I got the the video was kind oof a value added thing anyhow.....
1. 70-200 f4L IS is NOISE
2. off camera mic now on if acoustic or interview.....
3. IS off unless really needed while video capturing.......

thanks
Harry

Hi Cole

I've been talking with Harry via e-mail and I also couldn't get this clean enough to use - I think I had different clips - the one I worked on was fairly long.

Just for the forum record I tried using Izotope's noie reduction and I also got a clean noiseprint (ie just the IS noise by itself when he was just moving the camera around) from Harry and used this to train the Izotope NR. I pretty well got rid of the frying noise, but there was still a lot of other noise in the clip.

I'll post a couple of short excerpts later tonight when I get a little more time.

I can't help ya on the noise that's on there, but I can suggest the Rycote Lyre type shock mount with is designed for such noises. InVision Video » Rycote (http://www.rycote.com/products/invision_video/)
It may not fit the SVM, but for when you get a proper shotgun for outside, or hyper for inside, this will help kill the vibration.

Crazy thing is - the lens IS is that loud. It's not vibration as much as the motor is loud. The RODE SVM is suspended and all.

Thanks Cole

James in AZ tried too but the audio is doomed i'm afraid. the client is satisfied with the photographs I got the the video was kind oof a value added thing anyhow.....
1. 70-200 f4L IS is NOISE
2. off camera mic now on if acoustic or interview.....
3. IS off unless really needed while video capturing.......

thanks
Harry

IS should really be off most of the time anyway, unless you're shooting handheld. Most of the time video would be shot from a tripod and you'd never use stabilization when the camera is on a tripod, either for still work or for video. On a tripod it can actually introduce blur! For handheld, about the only time it really does much to improve sharpness is when your shutter speed is between 1/f and 1/2f where f is the lens focal length. Slower than 1/f it's impossible to get critically sharp even with IS on and faster than 1/2f it doesn't add anything.