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-20 level on minicam

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Craig Alan
-20 level on minicam
on Dec 10, 2011 at 9:35:07 pm

I'm sending a signal out mixpre-d and 302s to Canon hv40s. The cam's meters have indicators for -40, -12, and 0. When sending a 1k 0 level tone out mixer, is there a way to calibrate -20 on the camcorder more accurately than eyeballing it? Can I use an RTN cable for example and use the mixer's meters somehow to set the level on the camcorder?

Anyone know why the Canon doesn’t include a -20 indicator?

On a related note is -20 really exactly 0 on the mixer’s meter? +20 on the mixer will be overmodulated (peak) and on the camera peak is 0. (a -20 difference) But the lowest indicator on the mixer is -30 (total silence?) whereas on the camera it’s -40 (a -10 difference). Is there a formula that translates these two different scales? Just curious.

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz MacPro4,1 2.66GHz 8 core 12gigs of ram. GPU: Nvidia Geoforce GT120 with Vram 512. OS X 10.6.x; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP 6 certified; write professionally for a variety of media; teach video production in L.A.


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Ty Ford
Re: -20 level on minicam
on Dec 10, 2011 at 11:35:37 pm

Craig Alan]
Anyone know why the Canon doesn’t include a -20 indicator?

>>>>mfgr. ignorance.

On a related note is -20 really exactly 0 on the mixer’s meter? +20 on the mixer will be overmodulated (peak) and on the camera peak is 0. (a -20 difference) But the lowest indicator on the mixer is -30 (total silence?) whereas on the camera it’s -40 (a -10 difference). Is there a formula that translates these two different scales? Just curious."

>>>> Change the tone output to +20 on the mixer and then set audio record on the camera to just below clipping.

Regards,

Ty Ford

Cow Audio Forum Leader
Want better production audio?: Ty Ford's Audio Bootcamp Field Guide


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Craig Alan
Re: -20 level on minicam
on Dec 11, 2011 at 12:29:21 am

[Ty Ford] "Change the tone output to +20 on the mixer and then set audio record on the camera to just below clipping.
"


So if I do this, I can ride the gain on the mixer to anything up +20 and know that on the camera's meters I will be under 0, in other words not clipping. Obviously I'd need to leave some headroom.

Is this correct?

However, this still does not answer my question. If mixer/camcorder is 0/-20, +20/0, what does -30 on the mixer read on the camera? Is it -50 or -40?

[Ty Ford] ">>>>mfgr. ignorance."

Seriously?

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz MacPro4,1 2.66GHz 8 core 12gigs of ram. GPU: Nvidia Geoforce GT120 with Vram 512. OS X 10.6.x; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP 6 certified; write professionally for a variety of media; teach video production in L.A.


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Eric Toline
Re: -20 level on minicam
on Dec 10, 2011 at 11:35:58 pm

There is no -20 setting on the camera because Canon wants a -12 reference to cover the inherent noise of the electronics in the camera. If you can record a true -20 tone on what ever media the camera takes and play it back in the camera you can see exactly where -20 shows up on the meters.

Eric


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Craig Alan
Re: -20 level on minicam
on Dec 11, 2011 at 12:38:22 am

[Eric Toline] "There is no -20 setting on the camera because Canon wants a -12 reference to cover the inherent noise of the electronics in the camera."

Eric If I set 0 tone out mixer and calibrate to -12 instead of -20 I will increase the gain of the canon preamp not reduce it. However it is true that when recording on these small cams I try to keep the level as high as possible about 1/4 of way past -12 depending on how much control I have of the environment during shooting. For live events I'll leave the levels right at -12 or even a touch below so I have more head room.

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz MacPro4,1 2.66GHz 8 core 12gigs of ram. GPU: Nvidia Geoforce GT120 with Vram 512. OS X 10.6.x; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP 6 certified; write professionally for a variety of media; teach video production in L.A.


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Eric Toline
Re: -20 level on minicam
on Dec 11, 2011 at 3:58:15 am

Very true but the cameras record section performs better at -12 since the lowest levels will be higher at -12 than -20.

Eric


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Craig Alan
Re: -20 level on minicam
on Dec 11, 2011 at 9:38:06 am

Eric,

I know from experience that the best recording level for these small cams is at or slightly above -12. But I also know from experience that letting the mixer do a higher percentage of the preamplification yields higher quality/less noise. So why not use the traditional approach of calibrating 1k 0 tone to -20 on the camcorder and riding your mixer level from +8 to +16 thus the audio level on the camcorder will read -12 to -4.

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz MacPro4,1 2.66GHz 8 core 12gigs of ram. GPU: Nvidia Geoforce GT120 with Vram 512. OS X 10.6.x; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP 6 certified; write professionally for a variety of media; teach video production in L.A.


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Eric Toline
Re: -20 level on minicam
on Dec 11, 2011 at 2:05:38 pm

Craig,

As you've discovered there are many ways to answer the question and they all work.

Eric


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Craig Alan
Re: -20 level on minicam
on Dec 11, 2011 at 7:16:54 pm

[Eric Toline] "If you can record a true -20 tone on what ever media the camera takes and play it back in the camera you can see exactly where -20 shows up on the meters.
"


I could send a -20 signal out another mixer into the mixer attached to the camera. It would interesting to see what each meter reads. I believe Sound Devices mixers allow you to adjust the tone out level.

I will also try setting the camera's audio level indicator as low as possible and let the mixer do (almost) all the pre-amplification and see how that works. Then I could just note on the mixer's meters what reads as -12 tp -8 or so on the camera's meters. Even when calibrating to -12 or eyeballing -20 it has been a lot quieter than the camera left on its own. Juice Link has a tutorial video in which they tell folks to do just that -- lower the audio level as low as possible on the camcorder and let their device do as much of the amplification as possible.

OSX 10.5.8; MacBookPro4,1 Intel Core 2 Duo 2.5 GHz MacPro4,1 2.66GHz 8 core 12gigs of ram. GPU: Nvidia Geoforce GT120 with Vram 512. OS X 10.6.x; Camcorders: Sony Z7U, Canon HV30/40, Sony vx2000/PD170; FCP 6 certified; write professionally for a variety of media; teach video production in L.A.


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Eric Toline
Re: -20 level on minicam
on Dec 11, 2011 at 9:07:29 pm

The SD 442 lets you adjust tone via the menu. The settings are:
-20, -10, -8, "0", +4, +8 all dBu.

Eric


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