View Full Version : Mechanical zoom noise in GL2


Peter Bunge
February 7th, 2003, 10:53 AM
Has anyone had problems with mechanical zoom noise that sounds like tack-tack-tack at certain prts of the zooming. I'm not talking about the motor whirr. I observed this in a demo camera I almost bought, it is a hard rapping sound and comes out in the recording in a quiet room. I wound up with a new GL2 that works great.

Graham Bernard
February 7th, 2003, 11:24 AM
My quick answer is I haven't heard this.

Grazie

Chris Hurd
February 7th, 2003, 11:30 AM
Outside of my experience as well... sometimes the demo units are a little abused, maybe that's the problem.

Will Fastie
February 14th, 2003, 11:39 AM
I have not had the noise Peter describes, but the GL2 makes sufficient mechanical zoom noise that it was immediately picked up by the Azden SGM-X microphone I bought. I experimented with positioning the mic and found that I had to get it about 6" away from the lens barrel in order to lose the noise. The noise can be heard by putting my ear about 2" away from the lens, so it's not RF or electrical interference. Azden provided me with a shock mount for testing; it did not solve the problem, meaning that the noise is not being transmitted through the accessory shoe. The zoom noise is not picked up by the built-in mic.

My brother, who also owns a GL2, suggested that I disable automatic gain. The thinking is that that in quiet surroundings, the cam would crank up gain and thus pick up the zoom motor. With some background noise, it would not be evident. We have not yet tested his hypothesis.

In a face-to-face meeting with a Canon rep at a recent trade show in NY, I was told that such noise is typical, even in pro cams. I have no way of knowing if this is true.

I have sent an email to Canon asking if the built-in mic was filtering out camera noise and also whether the Canon DM-50 shotgun would filter out the noise. I haven't heard back yet.

Chris Hurd
February 14th, 2003, 11:56 AM
<< In a face-to-face meeting with a Canon rep at a recent trade show in NY, I was told that such noise is typical, even in pro cams. I have no way of knowing if this is true. >>

It is true.

The camera body itself is the single worst place to put a microphone. In some field situations such as journalism or news gathering, there is no choice but to take audio from the camera mic. There are tools available to dampen camera motor noise: see http://www.lightwavesystems.com/products/minimount/.

Most serious production work such as documentaries, narrative storytelling, etc. is done with mics everywhere except on the camera itself.

Also, I know all of the Canon reps who work the tradeshows. In fact I would have been in the booth with them at the New York DV Show, but instead I was at the other end of the hall working the booth for our sponsor Pro-Tape. I thought Madison Square Garden was a horrible venue for that show, but I love Manhattan so any excuse to go there is a good one. I met some great people at that show, but it was held in the wrong location. Next year it'll be in Javitts, hopefully.

As one of those Canon tradeshow reps myself, I can tell you in no uncertain terms that none of them would ever intentionally misrepresent themselves, or give you bad information, or tell you anything other than what they perceive to be the truth. Two of them, Dan and Don Berube, are also moderators here at dvinfo.net.

Most all of the Canon show reps, myself included, are independent "stringers" who work in the video production business, brought in to help with these tradeshows. We're not "real employees," just hired guns, end-users like you who enjoy working with this gear. We have no stake in Canon's profits or sales or success or whatever. In other words, there's no reason for any of us to ever give a booth vistor intentionally bad advice. Frequently we steer them to other cameras from Canon's competitors if we believe it's in the best interest of that person to do so.

We have a solid reputation as being some of the most helpful and honest and genuine people you'll ever find at a tradeshow. Because of this, we make Canon look good and that's why they keep calling us back regularly. If we didn't work the Canon booth, we'd be working for some other exhibitors (in the past, Canopus, VariZoom and Pro Tape for me, Tiffen and Apple for the Berube brothers, Media 100 for Adam Brooks and Jim Baker).

So in short, rest assured that when you visit the Canon booth, you are getting the truth as well as solid advice. If I'm there, I'll tell you what I can up to the limits of my non-disclosure agreement. If you're better off with a Sony camera, I'll tell you that. If you're better off with a less expensive GL2 instead of an XL1S, I'll tell you that as well. I'll also tell you that most all camcorders suffer from motor noise getting onto the audio track due to the proximity of the onboard mic, and how you can deal with it to minimize that issue. Finally, I'll also tell you that yes, the DM-50 dampens most of the camera noise and that's why I list it on my Top Ten GL2 Accessories page at http://www.dvinfo.net/canongl2/articles/topfive.php.

Hope this helps,

Will Fastie
February 14th, 2003, 11:34 PM
Chris:

Thanks a lot for that thorough comment.

I probably should have worded my post a bit more carefully. I didn't mean to imply that the Canon rep was lying but rather that my own experience is limited. I have no experience with pro equipment, so I had nothing upon which to base the rep's comment. But I did assume that I was speaking to Canon. When the rep did not ask me any detailed questions and then issued a blanket statement that the noise was "typical," I filed the info away under "unconfirmed."

Can you shed any light on whether the GL2's on-cam mic is actually cancelling camera noise?

I did see your positive comments about the DM-50. I considered that mic before I bought the Azden, but I rejected it because a) I could not find the mic's specs on canondv.com and b) the response I got when I emailed and called for the info was that the specs were not available. Do you know the specs for the DM-50?

I am aware of Lightwave's minimount. It does not appear that it could get my SGM-X much further away from the lens than Azden's own shockmount. Instead, I bought NRG's Tri-Mount, which raises the shoe about 5". I haven't done the tests yet, though.

A lot of this is moot. In my project, the vast majority of cam-captured audio will be one person talking, so I already have lavalieres. After spending all this money on the cam-mounted solutions, I find I'm getting at least very good results with a cheap, $35 wired lavaliere and with Sony's $99 wireless kit. Still, just the other day I was doing home movie chores at a friend's house using only the GL2's mic and the results were mediocre at best (and zoom noise didn't enter into it).

Will

Graham Bernard
February 15th, 2003, 01:11 AM
I've had zoom or maybe lens focus rumble picked up on my Senni. However there is a very tiny DIP switch located just above the ON/OF switch. This needs to be in the "closed" postion to reduce the more bass noise from this type of rumble - yes? As of yet I haven't done a test to confirm or deny the effacacy of this switch. But there again I can't assume it will not work, as Senni has made provision for it - yes?

Grazie

Ken Tanaka
February 15th, 2003, 02:24 AM
Grazie,
That switch is called the "bass roll-off' switch, signified by that ramp symbol (as on many other mics). It does, in fact, really attenuate low frequencies and helps to reduce hum and rumble. You can try it for yourself by monitoring audio with good headphones in, say, a somewhat noisy urban oudoor environment.

I doubt, however, that lens servo sounds would fall into the attenuate range.

As Chris noted, the camera is the worst place for audio capture.

Graham Bernard
February 15th, 2003, 02:47 AM
Does Canon do a Baseball Cap accessory - so I can fix my Senni on top of my head - neat solution? hee hee

Thanks for the feedback though - I'll start with some test - as soonas I've shifted this wretched head cold! It's murder - really! Sniff sniff cough . . . splutter . . .

Grazie

Chris Hurd
February 15th, 2003, 02:59 PM
Hi Will,

<< Can you shed any light on whether the GL2's on-cam mic is actually cancelling camera noise? >>

I don't believe it does that.

<< Do you know the specs for the DM-50? >>

Well, what I can tell you is that it's a consumer-grade mic and if you feel you need to know the specs, then it probably isn't the right mic for you.

<< I am aware of Lightwave's minimount. It does not appear that it could get my SGM-X much further away from the lens than Azden's own shockmount. >>

But the LightWave mount *is* first and foremost a noise-dampening mount. It's not about how far away from the camera the mic is mounted, but rather how much noise is killed. The Mini-Mount's suspension cradle eliminates most if not all of that noise (noise that is transferred through actual physical contact, not through the air). Hope this helps,

Will Fastie
February 15th, 2003, 03:14 PM
Chris:

The DM-50 at $150 sneaks over my Maginot line for consumer toys, which is $99. I paid $150 for the Azden mic, admittedly low end but not what I consider a consumer buy. (Maybe I'm just cheap -- my project certainly is on a low budget.)

Having invested in the GL2, I now have an ongoing gripe with Canon about the lack of information on its site. There are few details on any of the accessories. I easily found the specs for the dirt cheap Audio-Technica lavaliere mic I bought ($35). I'm so ignorant about all things video that I feel lost when I can't find these details.

I'm sure the LightWave Mini Mount dampens sound well; I have the superb LightWave windscreen that exudes quality. But I'm not getting mechanical noise through the mount, I'm getting ambient noise. If I hold the mic in my hand about the same distance from the lens as it would be if mounted, I still pick up the zoom noise.

And getting back to the on-cam mic, I remain mystified as to why it doesn't pick up the zoom noise if it's not cancelling.

Chris Hurd
February 15th, 2003, 03:41 PM
Hi Will,

<< I now have an ongoing gripe with Canon about the lack of information on its site. >>

This was the primary reason why I started the XL1 Watchdog back in 1998. Its follow-up, the GL2 Son of Watchdog pages, are expanding as people find and submit the info. Keep an eye on it at http://www.dvinfo.net/canongl2/index.php

Will Fastie
February 15th, 2003, 04:06 PM
Chris:

I've been watching!

Will

Don Palomaki
February 16th, 2003, 08:48 AM
The GL1 mic (I assume the Gl2 mic is similar) is a 4-element design. And I suspect that the configuration would tend to cancel near field nose from the camcorder. Mounting an external mic will probably not have some of this near field benefit - depending on the design of the mic. The Azden's pattern may even have side lobes that tend to pickup any camcorder noise with minimal attenuation relative to its front sensitivity. And there are no doubt singificant variations in the mechanical noise levels of individual camcorders.

Marco Leavitt
February 16th, 2003, 11:22 AM
How's the NRG Tri-Mount working out for you? I'm still trying to find the best way to mount a light and a microphone and had seen that thing. It's certainly odd looking. Is it stable?

Will Fastie
February 16th, 2003, 07:45 PM
Don:

There were some changes in the GL2's audio system, but I think you are correct that the mic itself did not change.

Know anything about the DM-50?

Will Fastie
February 16th, 2003, 07:51 PM
Marco:

I don't yet have good field experience with the NRG Tri-Mount.

It is very strong and it mounts firmly to the cam. I don't see any problem with putting a pound or so of stuff on it, maybe more. I have some old ARC on-cam, 150W lights I bought on eBay that I like a lot; it's pretty heavy but because it's intended to mount in the shoe anyway, I think it could sit anyware on the Tri-Mount.

I have not yet done the test with the mount, which is to put the SGM-X in the Azden shock mount on top of the Tri-Mount to see if I still pick up the ambient noise.

At $23, it did seem to be a pretty expensive hunk of aluminum considering it's only 5" tall.

Brad Higerd
February 16th, 2003, 08:07 PM
For what it's worth, I have made a mount for my Sen ME66K6 from a Beyerdynamic EA86 and a Sen MZQ6. I hack sawed off the end of the Sen standard mount and drilled a large shallow hole in the end. Then I replaced the brass threaded bottom of the Beyerdynamic shock mount with the larger diameter stud that came packaged with it. I then hack sawed off the stud so that only about 1/8" was showing and threaded it into the drilled hole. With a little epoxy glue and a prayer, an extremely quiet shock mount was produced.

The advantage of the Sen mount was its firm attachment to the GL2, and the advantage of the Beyerdynamic was its effective shock dampening ability in a very low-profile design.

My ME66 is now about 5" from the lense, and you can literally hear a whisper across a room (provided the room is quiet).

Graham Bernard
February 17th, 2003, 01:18 AM
Errrmmmm... Brad, any chance of a picture of your handy work? Very interested.

Grazie

Don Palomaki
February 17th, 2003, 07:22 AM
Will,

I don't have any good information about the DM-50. Some folks seem to like it.

Will Fastie
February 17th, 2003, 07:27 AM
Don:

I decided to start a new thread directly on topic to see if I can shake anything loose.

Thanks anyway.

Will Fastie
February 19th, 2003, 07:00 PM
I'm very grateful to Tom Voight, a DM-50 owner who posted the following notes in the "DM-50 Owners: Got Specs?" thread:

Type: Back electret stereo condenser shotgun microphone
Directivity: Super-directional/Uni-directional stereo
Sensitivity: -40dB/PA (0 dB= 1V/ 1 Pa, 1 kHz front, along axis)
Frequency: 150-15,000 Hz
Output impedance: 200 ohms (1 kHz)
Operating temperature range: 0-40 C
Dimensions: 32x81x150mm, 120g

I can't compare it to any other microphone, but I like it a lot. It produces a very nice recording of music and voice with a very good stereo image (in the center, stereo shotgun, setting).