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Black Magic 4k sound


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So my partner is one of the first 12 people to receive the first shipment of the Black Magic 4k camera. We've tried some lenses out and I must say the imagery is stellar. Looking for anyone with information on the audio for this camera. We are discussing going into the camera with a breakaway cable from a location mixer. Looking for any info on audio quality of the camera, timecode and syncing issues. We will be doing some experiments in the next few days. An insight is appreciated.

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On that photo website, they seem to enjoy the picture part but not be impressed at all by the audio functionnality. As for sync/TC there's no comment so far and, in fact, no TC dedicated connection on the unit if I have a quick look at the pics (?).

 

Audio

Sadly, there are issues with the BMCC audio. First among them is that while there is a built-in mic, it mostly picks up camera fan noise. It is barely usable as a sync track, and definitely for nothing else. But, that's not the real issue. There are no audio meters. There are two input jacks (1/4" phono jack) and a level control, and the ability to switch between Line and Mic level, etc; but no meters. WTF! Who at Blackmagic allowed this? People have been bitching about it since the first cameras were announced but it has never been addressed in a firmware update. While one can give the video portion of this camera an A, the audio gets a D – must improve before term-end, or getting flunked is a certainty.



Link ref.:

http://www.luminous-landscape.com/reviews/camcorders/bmcc_first_impressions.shtml


I guess a clap in the road-case is a good idea for these shoots. Also sending scratch-track into audio inputs (+or- audio TC).
Double system might rule, again. (and blimp that fan noise maybe?)

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Here in the Sound Department, we have an old saying for toys like these……. "Treat it like Film"

 

Double System with Timecode Slate = Happy Days.

 
By all means send a scratch track to the camera, but at the end of the day if you go with this time tested technique you will have:
 
- Highest possible audio quality
- Multitrack capability
- No Timecode issues
- No Sync issues
 
Anything else is a compromise and in many cases false economy !!!
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I had Trew Audio specially make a cable with TA5 to 1/4" jacks.  I used an SRb at +05 and line level at 100%... modulation levels was spot on at 0dBu - -20dBFs, but there was a distinct noise floor issue.  I changed the SRb to -20 (or was it -25) and set BMCC to mic level, 50% gain, and there was a marked improvement.  I still think that a Canon 7D at mic level, sounded better though.

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Here in the Sound Department, we have an old saying for toys like these……. "Treat it like Film"

 

Double System with Timecode Slate = Happy Days.

 
By all means send a scratch track to the camera, but at the end of the day if you go with this time tested technique you will have:
 
- Highest possible audio quality
- Multitrack capability
- No Timecode issues
- No Sync issues
 
Anything else is a compromise and in many cases false economy !!!

 

That's the truth.

CrewC

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Here in the Sound Department, we have an old saying for toys like these……. "Treat it like Film".  Double System with Timecode Slate = Happy Days. By all means send a scratch track to the camera...

 

whssign.gif

 

I generally love Blackmagic as a company, but they really fell down with their cameras, especially in terms of timecode and audio. Be sure to put a timecode jam box on it, like the Denecke DB-T or an Ambient Lockit.

 

I haven't had to deal with a BMCC 4K camera yet in post, but I have used the older 2K camera and was not impressed by how much it crushed the blacks. This could have been an exposure issue by the DP, but all the other cameras on that recent project (mostly Alexa) looked fine. I gotta say, though, for $3000, it's a great deal, and the test pix I've seen on the CML list look very good when exposed perfectly. 

 

I think the Alexa and Red Epic have better dynamic range and better exposure, but they're not 10 times better for 10 times the money. I think Red will have a big problem trying to compete at the low end with cameras like the BMCC.

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I've done jobs with both of the BM cams, hooked them up to cabled feeds and listened to returns from them while rolling.  My conclusion so far: a Canon 5D has hifi audio compared to the BM cams.  Really noisy, really low headroom, really poor resolution--bad enough that I wonder why the audio feature is there at all.  A not very good guide track, like not nearly as good as DSLR audio, is what you get.

 

philp

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What I heard back on a return from a BMCC sounded just like Philip said.  It also appeared to roll-off everything below about 200Hz.

 

I noticed this on a BlackMagic 2k camera too. It had a Rode Mic on which normally sounded good on a 5D. On the BlackMagic camera the sound quality was significantly reduced, like you say. I also noticed that in this case there was a cheap cable adapter which split the mini-TRS of the Rode Mic into separate TS plugs. The inputs of the camera are balanced TRS connections. I haven't investigated if it's the adapter and connectors being the fault here. It was a cheap 'solution' to my eyes but an expensive 'solution' in my ears.

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Ouch. Looks like it's probably on the way for an eventual use with a separate recorder like some "4K AJA or PIX" to get all the needs/connections gathered together then? And a rig for all these add-ons i guess...

I'm curious about that fan and to what point it could be noisy for interiors (and if there's any control for it in the menus)?

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I looked at the camera online and unless I am mistaking, there's no timecode input on the camera. So scratch track or a small mic on it seems like the only way. Slate or a beep ( tone ) at the begging in or end of each take. I also usually just say the audio file number after the beep just to make it easier for post.

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I noticed this on a BlackMagic 2k camera too. It had a Rode Mic on which normally sounded good on a 5D. On the BlackMagic camera the sound quality was significantly reduced, like you say. I also noticed that in this case there was a cheap cable adapter which split the mini-TRS of the Rode Mic into separate TS plugs. The inputs of the camera are balanced TRS connections. I haven't investigated if it's the adapter and connectors being the fault here. It was a cheap 'solution' to my eyes but an expensive 'solution' in my ears.

In my case I was using a Schoeps mic and an external mixer.

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I looked at the camera online and unless I am mistaking, there's no timecode input on the camera. So scratch track or a small mic on it seems like the only way. Slate or a beep ( tone ) at the begging in or end of each take. I also usually just say the audio file number after the beep just to make it easier for post.

Aux TC is what I use on my BMD cameras.

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Have sent audio to this camera for sit down interviews. Hardwired. Mic level out of 664. Mic level in camera, input level @ 75%.

Always give client 664 master audio.

TC slate before each take.   

At line level the input sliders on the camera seem to have no effect.

No meters made me lose my mind. Really? Do a test record, import to final cut to check levels. Crazy.

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