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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Sound ?!

Elizabeth said:
Are there a visual audio level meter in the camera menu display window?

I have seen no mention of this feature, so I am guessing not.
Click to expand...

Isn't that what you're looking for (from the manual) :
Just as linear response RAW video data is converted to REC 709 for metering, the linear response audio data is converted to Log Base 10 data for metering. A color coded 4 channel audio meter is provided in the lower section of the camera GUI. This information is visible in the RED-EVF, RED-LCD and HDMI (DVI) monitor outputs.
Click to expand...
 
Perfect!

Thanks, this is just what I was looking for (I guess I miss it in my read through).

Seeing that there is no index in the Operations Guide, would you be so kind as to give a page number for this manual quote? Much appreciated.
 
Yes but the question is: when the menu overlay is visible so you can adjust the gain, are the meters still visible?
 
The "no physical audio level knobs" issue has been discussed at some length several months ago. I haven't heard anyone liking it, but there are workarounds. Apparently a yet-to-be-offered control grip that connects via USB will have some programmable knobs, which may be used for audio levels. Maybe there will be a market for a cable that combines mini-to-std. XLR plus an attenuator knob.

I'm guessing Red's design philosophy went something like this: on a big production, you'll be taking a feed from a mixer and they can adjust levels at the mixer. On a small production with no soundman, your camera op. is going to have their hands full just running the camera and they aren't going to be riding levels anyway, they'd be set up on the initial sound check and not touched thereafter. (In practice, the latter situation is how I've always worked.)
 
Elizabeth said:
Perfect!

Thanks, this is just what I was looking for (I guess I miss it in my read through).

Seeing that there is no index in the Operations Guide, would you be so kind as to give a page number for this manual quote? Much appreciated.
Click to expand...
The text I quoted is page 11, and the menus are described page 33-35.
 
Thanks.
 
Red really needs to have some kind of trim control available to precisely set the ref audio levels on line in (could be in a menu). Every other professional camera has this--it can't be that tough to do. Output levels from various mixers vary, and the way we trim everything is to output a level that reads at a correct level on the mixer, trim it up to the desired level on the camera, and then adjust the levels of the returns to the mixer so that all read the same. Not having trim in the camera is a serious oversight--you cannot count on the audio mixer having a precisely .775 v output, other voltages/levels are often used as "0".

I would not count on professional sound people sending this camera 4 discrete channels of audio very often. For one thing it will make the camera snake larger, heavier and more expensive, and for another Red does not provide 4 audio outputs so the sound person can properly monitor the tracks both together and individually. (Which would require an 8 line +TC snake.) With the meters only visible in the finder, I would say that getting a 2 track mix feed to the camera would be a good goal, with iso tracks recorded elsewhere w/ TC. Since this camera makes files and not tape, snapping the iso tracks to the camera tracks via TC stamps in a NLE will be pretty simple.

I'll be interested to see what sorts of solutions people renting Red cameras will come up with to interface its audio ports with the connectors used in the rest of the industry. I for one would like to keep things fairly standardized, ie XLR3-Fs on input and XLR5-M for output.

If anyone in the SF area has a Red with the audio enabled, I would gladly volunteer myself and gear to do some tests.

Philip Perkins CAS
 
With 24 bit and (hopefully) good preamps and A/D converters in the RED you can use a nominal level of -32 dB or even lower in order to have enough headroom for peaks without clipping.

HVX/DVX guys, you're no longer in a 16 bit world here! :-)
 
jbeale said:
The "no physical audio level knobs" issue has been discussed at some length several months ago. I haven't heard anyone liking it, but there are workarounds. Apparently a yet-to-be-offered control grip that connects via USB will have some programmable knobs, which may be used for audio levels. Maybe there will be a market for a cable that combines mini-to-std. XLR plus an attenuator knob.

I'm guessing Red's design philosophy went something like this: on a big production, you'll be taking a feed from a mixer and they can adjust levels at the mixer. On a small production with no soundman, your camera op. is going to have their hands full just running the camera and they aren't going to be riding levels anyway, they'd be set up on the initial sound check and not touched thereafter. (In practice, the latter situation is how I've always worked.)
Click to expand...
Yes, I do remember discussions about the "supergrip" being able to control audio gain. I guess we'll have to wait and see if that works...

But what I'm trying to find out is, whith the added dynamic range gained by using 24 bit per sample compared to the usual 16 bit, is it still necessary to be able to adjust the gain during a shot ?
I'm just asking, I'm not a sound guy...:unsure:
Wouldn't adjusting the gain to match the sensitivity of your microphone be enough ? You would just adjust the gain at the beginning in order not to clip, and then you'd adjust levels in post during the mix session ?
I'm talking ENG / EFP situations here, obviously. When you have a sound guy using an external mixer, this shouldn't be an issue anyway.

I mean, it's the same with the ISO adjustment in the camera. Nothing is done in camera (only metadata), everything is adjusted in post...

In fact, that's how I understand what they say in the manual. What do you think ?

Nils.
 
big lebowski said:
With 24 bit and (hopefully) good preamps and A/D converters in the RED you can use a nominal level of -32 dB or even lower in order to have enough headroom for peaks without clipping.

HVX/DVX guys, you're no longer in a 16 bit world here! :-)
Click to expand...

That may be true, but we generally find that in almost all location dialog recording the difference between 16 bit and 24 bit audio is negligible--the noise floor is too high to tell the difference. As for recording at very low levels in a some kind of a set-and-forget setup, this isn't a good idea either. You will find in post that this dynamic range will have to be compressed a good deal to be used, and that in bringing up the low level audio you will bring up all kinds of system noise with it, requiring time consuming noise-reduction and further damage to your audio. Just having 24 bits is no guarantee of good sounding audio, and not a reason to become lax about proper level setting and gain riding during recording. In the audio world, a 24 bit A-to-D convertor that is actually 24 whole bits has yet to be made--the reality is that they work at between 18-20 bits most of the time. I look forward to hearing what Red has come up with. Does any one know what chips they are using for this?

Philip Perkins CAS
 
philper said:
That may be true, but we generally find that in almost all location dialog recording the difference between 16 bit and 24 bit audio is negligible--the noise floor is too high to tell the difference. As for recording at very low levels in a some kind of a set-and-forget setup, this isn't a good idea either. You will find in post that this dynamic range will have to be compressed a good deal to be used, and that in bringing up the low level audio you will bring up all kinds of system noise with it, requiring time consuming noise-reduction and further damage to your audio.
Click to expand...

I don't say that the mixer should be working at a lower level. In the analog world there's no hard clipping at 0 dB anyway. I'm only talking about the level you set for recording on the RED.

philper said:
Just having 24 bits is no guarantee of good sounding audio, and not a reason to become lax about proper level setting and gain riding during recording. In the audio world, a 24 bit A-to-D convertor that is actually 24 whole bits has yet to be made--the reality is that they work at between 18-20 bits most of the time.
Click to expand...

That's why I said -32 dB and not -60 dB. :wink:
 
It would be nice if someone posts some properly recorded audio samples now that there are more cameras in the world.

Uncompressed WAVs in a RAR archive or compressed with Monkey Audio or some other of the free lossless codex. [I don't think mp3s or other lossy samples would be appropriate.]

Thanks in advance.
 
First, trust what Philip Perkins says. He's a great resource on various audio forums and been doing location sound for a while.

I see the 4 channels on the Red as providing a solution for those who may be in a situation where you don't have a sound man or exetrnal mixer to work with but yet you'd like to get a boom and 2 or three lavs recorded separate. Otherwise, a more common double system approach would be utilized. A mixer (say a 442) running through a 744 and also routed to camera for reference with some kind of mixdown. There are all kinds of scenarios that will call for unique audio needs but on most of the jobs I would see this camera being used for there will be a competent sound team involved and they will collaborate with the camera crew to make sure that audio is being routed where it needs to and that the levels to and from the camera are set properly. The Red does pose an interesting challenge at the moment with the lack of external pots, but I believe this will be solved with Supergrip or other 3rd party accessories.

Philip, if you do get a chance to do some tests before I get my hands on a camera it would be very useful to see what you think of the audio - both ergonomics and sound quality. I have practical expectations for sound quality but Red has been known to exceed our expectations.

Thanks for joining the conversation!

Steve
 
one configuration

one configuration

here is one config, mounting mic off universal mount in front.

it is what i am using today here in the middle east...
 
stevesherrick said:
First, trust what Philip Perkins says. He's a great resource on various audio forums and been doing location sound for a while.
Click to expand...

I never questioned his competence. I just brought up some ideas based on my audio studio experience.

Anyhow, we all have to run our own tests to find out what works best.
 
ibloom said:
Thats like 23.3 stops of audio right?
Click to expand...

With audio you say dB, not stops. 6 dB corresponds to one bit of signal resolution. So 24 bits has a theoretical dynamic range of 144 dB. But as pointed out, it all depends on the quality of the weakest link in the chain. And this is usually much lower than that.
 
Offhollywood said:
I am actually going to feed all original channels from the mixer to the camera on my next production. Hard disc recorder (Metacorder) as back-up ONLY and for when we can't be teathered. The reality is - MOST OF TIME you run cables anyway for an HD monitor. Cables on set with a good crew is not really an issue to me - especially if you always have BWF back ups anyway. Getting QT wrappers off the camera with FOUR separate tracks of audio which can be transcoded immedaitely is a HUGE deal as far as I am concerned - and I will use the hell out of it -
Click to expand...

It's nice until picture lock aye, do a little mixing and cutting in FCP. But later your going to autoduck it to protools right. The sound guys I work with are pretty finicky about their recorders and pre-amps, we bypass in camera sound when possible. Red's great, but Red's not an audio company. Maybe Jarred needs to post a picture of the audio guy at Red (holding an Uzi while riding waterskis or something).

Ibloom
 
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