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Inputting Sound into the camera: aargh!


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#1 Lawrence Karman

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Posted 10 January 2012 - 10:38 PM

I just finished working on a few commercials and was introduced to a new phenomenon: having to input sound to the Alexa camera. I'm told, due to the short turnaround time on commercials, the editors have been requesting this. Last month I dealt with this by asking for a Comtex receiver (small, lightweight) to input what I thought was only scratch track. It was getting some static and this was not good enough for their needs and next thing I knew I was being handed a thick piece of cable with 2 XLR cables inside to plug into the 5 pin to dual 3 pin splitter that came with the camera (in addition to the thin BNC cable I was already running from the camera-no HD transmitter). Needless to say this made operating difficult.

The next commercial I had with the Alexa I spoke to the sound mixer before the job and requested he bring a quality receiver. I was given a receiver a step above the Comtex and an hour into the day I was handed another thick dual XLR cable to plug into the camera with the explanation that the client is demanding Stereo production quality sound be inputed into the camera. I asked for some better quality wireless receivers and was told they don't want to pay an extra $130 to rent them from the sound man. Another shitty day ensued.

Back at home that night I found buried in my garage a super thin shielded cable (don't ask me where i got the cable) with 5 pin XLR connectors at each end I had made up once for headsets/intercom on some live TV work I did. Salvation!! I can't tell you what a difference it made to the operating. Sound mixer asked that I keep cell phones away from it but otherwise he was happy.

The point of this is to say make yourselves one of these cables, you'll be glad you did. And tape a thin BNC to it so you'll be covered for HD viewing.
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#2 William Demeritt

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Posted 10 January 2012 - 11:13 PM

They want to hurt the costly investment of having a Steadicam operator because the editor doesn't want to pay $150 for a copy of PluralEyes? Makes perfect sense.

In the past, if a Comtex for camera isn't available, I put on my best grimace and when asked if I minded operating tethered, and respond "How about you give me your smallest, most compact microphone, mount it to the camera and run that into the camera's audio input? That way, you get a scratch track on the clips and the slate, and just use a cheap tool like 'PluralEyes' to sync it up for you."
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#3 Ian Thomson

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Posted 11 January 2012 - 05:06 AM

I just finished working on a few commercials and was introduced to a new phenomenon: having to input sound to the Alexa camera. I'm told, due to the short turnaround time on commercials, the editors have been requesting this. Last month I dealt with this by asking for a Comtex receiver (small, lightweight) to input what I thought was only scratch track. It was getting some static and this was not good enough for their needs and next thing I knew I was being handed a thick piece of cable with 2 XLR cables inside to plug into the 5 pin to dual 3 pin splitter that came with the camera (in addition to the thin BNC cable I was already running from the camera-no HD transmitter). Needless to say this made operating difficult.

The next commercial I had with the Alexa I spoke to the sound mixer before the job and requested he bring a quality receiver. I was given a receiver a step above the Comtex and an hour into the day I was handed another thick dual XLR cable to plug into the camera with the explanation that the client is demanding Stereo production quality sound be inputed into the camera. I asked for some better quality wireless receivers and was told they don't want to pay an extra $130 to rent them from the sound man. Another shitty day ensued.

Back at home that night I found buried in my garage a super thin shielded cable (don't ask me where i got the cable) with 5 pin XLR connectors at each end I had made up once for headsets/intercom on some live TV work I did. Salvation!! I can't tell you what a difference it made to the operating. Sound mixer asked that I keep cell phones away from it but otherwise he was happy.

The point of this is to say make yourselves one of these cables, you'll be glad you did. And tape a thin BNC to it so you'll be covered for HD viewing.


G'day Lawrence, sucks that you had to be tethered on account of the sound requirements...

better than hard-cable = Lock-it box
.
The Alexa has pretty good Timecode for a cine-camera (cough-REDsux-cough) and can usually stay in sync with the audio gear if Jammed at the beginning of the day (edit - needs to be re-jammed after battery-changes)
even better is to Jam-sync a Lock-it box, and place that on the rig - it'll continuously feed the Alexas TC input. and provide identical timecode to the audio recorder.

no need for scratch-tracks that drop out with distance or interference
no need to digitize/conform the footage/audio (plural eyes takes time)
no need to run multiple cables for multiple tracks (editing can line-up as many tracks as the sound mixer records)
no chance of using the reference tracks in the final mix (should be able to get support from your sound mixer here)
cheaper than a stereo wireless link.
Auto-sync in FCP and most avid systems. (ie: less than 20 key-strokes and 5mins time)

just film a regular slate as back-up (or TC slate to be really fancy)
you would still need a comtek for reference playback if there isn't a video-split recorder on set... but at least a comtek is wireless and light-weight :)

only reason I can think that they'd say no is the minimal cost. or some antiquated editing protocols from the days of liner HD tape. (which they shouldn't be using with the "flie-based" Alexa anyway)

but it's really that much better for you... and for the final product.

it's getting a hard sometimes to understand why people make requests that don't really save time in post, and make lives MUCH harder in production...

all the best

Ian

P.S. the 5-pin cable will share electrical grounding for both L+R audio. it's unbalanced and MUCH more susceptible to inteference (from cell phones/wireless video transmitters, and neon-lights, etc), but if you've gotta fly with it - go the thin stuff

Edited by Ian Thomson, 11 January 2012 - 05:07 AM.

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#4 Robert Starling SOC

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Posted 11 January 2012 - 09:45 AM

There may be an option in a new on-board recorder I just bought; the Sound Devices Pix 240.

http://www.sounddevi...roducts/pix.htm

I really love this thing! Although I've yet to make a nice mounting bracket for it.

We used it last week on a RED EPIC job and one of the great things about it is that it down or upconverts the incoming SDI or HDMI signal real time on the fly to an Avid or Apple ProRes file. We used it last week so we didn't have to transcode the EPIC footage. It was a lifesaver

It's about 5-10% larger than a Dionic HC so I wish it was a hair smaller but I can tell I'm going to get a lot of rentals for this on RED jobs where they don't need to full-on RED media.

As soon as I get a slick bracket made up I'll post photos and a review.

Anyway, my point is that it has two professional XLR inputs for audio or you can use the embedded 8 channels of audio off the incoming HD-SDI signals.

Robert
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#5 Lawrence Karman

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Posted 11 January 2012 - 10:12 AM

Both me and the mixer tried to explain about PluralEyes and the simplicity of syncing in post but they did not care. They want to hand over the hard drives already synced to the editor and I suppose have these spots cut by lunch. Who knows, but they are not interested in my problems. I tried explaining to the producer in both cases that the quality of the work would be affected but I guess they had bigger things to worry about.
And as always, we had a lock-it box on board with time code slates.

Robert, that sounds like a good recording option for RED. Alexa already records Pro Res so not necessary.
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#6 Alfeo Dixon SOC

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Posted 11 January 2012 - 03:30 PM

The sound guy had this Cat5 jumper made that made my life soooooo much easier. The thing I HATE the most is... "well if you have one cable (super thin spaghetti bnc) then what's another cable?!?" as they dangle a what THEY called a lightweight cable at you.

Referring back to this old thread: http://www.steadicam...indpost&p=36665

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#7 Lawrence Karman

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Posted 11 January 2012 - 09:07 PM

The sound guy had this Cat5 jumper made that made my life soooooo much easier. The thing I HATE the most is... "well if you have one cable (super thin spaghetti bnc) then what's another cable?!?" as they dangle a what THEY called a lightweight cable at you.

Referring back to this old thread: http://www.steadicam...indpost&p=36665



Oh yes, I forgot about those. Thanks Alfeo. Seems like the sound dept is not usually prepared to come up with stuff like this. "Just throw the cable over your shoulder" I was told.
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#8 Osvaldo Silvera SOC

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Posted 12 January 2012 - 10:23 AM

Thanks Alfeo!,

Just found the Muxlab 500012 on the B&H site. I guess you'd be able to make your own breakout cables for this to provide 2 channels of audio, one video and then the headphone loop. Great idea for the tethering minded folks....
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#9 Lawrence Karman

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Posted 12 January 2012 - 10:31 AM

I'd love to know where to buy a set like that. the two boxes and two breakouts with maybe an 8' cat 5 lead.


Maybe this:

http://www.markertek...html?MUX-500033
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#10 Afton Grant

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Posted 12 January 2012 - 12:03 PM

Just curious if those Muxlab boxes contain signal boosters of any kind, or are they just simply junction boxes?
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#11 William Demeritt

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Posted 12 January 2012 - 12:53 PM

Appears to be just junction boxes, the specs don't seem to have any indication of power input to amplify the signal.
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#12 Alfeo Dixon SOC

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Posted 12 January 2012 - 02:06 PM

I'm actually working with the sound guy that had it made tonight on 2nd unit... I will ask him about the boosting and I do believe he was not able to hear the return from the camera, not sure, but will ask that also. I think that is a great little trick to have in your bag. Maybe a group purchase on that breakout cable would help bring cost down also.
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#13 Afton Grant

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Posted 12 January 2012 - 02:06 PM

If there's no amplification or electronics of any sort, it seems like a lot of unnecessary hopping going on...

cable from mixer > breakout cable > junction box > cat 5 > junction box > breakout cable > camera

That's six connections, two of them being RCA and two being Ethernet - neither of which are terribly substantial. Why not a simple jumper made of that Cat5 cable with dual XLRs at either end?

cable from mixer > cat 5 > camera
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#14 Alfeo Dixon SOC

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Posted 12 January 2012 - 02:29 PM

cable from mixer > cat 5 > camera

what type of adapter/connector to and from cat5?


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#15 Afton Grant

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Posted 12 January 2012 - 06:42 PM

cable from mixer > cat 5 > camera

what type of adapter/connector to and from cat5?


It would terminate in the appropriate XLRs at each end. Dual female XLR3s at one end, Dual male XLR3s at the other. No need for those junction boxes. The Cat 5 cable is the important bit, but it doesn't need to end in Cat 5 connectors.
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