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Pocket camera HDMI behaviour


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#1 Phil Rhodes

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Posted 01 March 2014 - 01:52 PM

I read with pleasant surprise that the Blackmagic pocket camera provides 10-bit 4:2:2 HDMI output - although the manual says it does this while recording.

 

This strikes me as a more than slightly weaselly phrase. Does anyone know what it outputs while not recording?

 

Have they deliberately crippled the damn thing?

 

P


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#2 Tyler Purcell

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Posted 01 March 2014 - 02:13 PM

Interesting, I wonder if to save battery and keep the heat down, they're limiting the CPU's speed when not recording. The standard cinema camera has a fan to keep it cool, but the pocket doesn't. I have noticed my pocket gets really hot when shooting, but doesn't get hot when left powered on and at idle. That could be evidence...
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#3 Phil Rhodes

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Posted 01 March 2014 - 03:06 PM

Hmm, interesting.

 

Any chance of patching it up to a display and seeing what goes on when you start and stop? Does it re-initialise the HDMI connection?


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#4 Peter J DeCrescenzo

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Posted 01 March 2014 - 06:52 PM

Perhaps the BMPCC pocket cam doesn't do video compression (either ProRes HQ or compressed RAW) when it's powered-on in idle mode (not recording). That might explain the operating temp difference between idle and recording.

 

I don't know if a BMPCC outputs a different live video signal when in idle vs. recording, regrets.


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#5 Phil Rhodes

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Posted 01 March 2014 - 08:53 PM

Apparently it's fine:

 

http://forum.blackma...php?f=2&t=17380

 

Original poster seemed confused, but apparently it's fine.

 

There is no timecode over HDMI with the pocket camera, but then I'd be patching it up to a Samurai anyway, and they're both LANC-compatible devices so the record start/stop is easily dealt with in both cases. Wonder if they'd be frame accurate...

 

I do rather like the fact that the HDMI to SDI mini-converter has the ability to embed AES audio, so I can throw in a nice clean AES mic preamp. And the Samurai has the ability to take out any audio-video latency that creeps into this chain of destruction.

 

You see where I'm going with this, anyway: 10-bit 4:2:2 camera with top quality audio and (to an extent) B4 lens compatibility. Total cost, not including the B4 lens, what, $3-4k?

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#6 Matt Grover

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Posted 02 March 2014 - 09:38 AM

My thoughts on this, haven't noticed this particular issue, although the BMPCC IS funny about what displays you plug it into, for example it doesn't seem to output to any HDMI TV's that I've tried, knowing they accept various resolutions and rates (e.g.: Panasonic Viera and Sony Bravia), but it DID work plugged into a 7" TVLogic monitor. I've been liaising with BMD support on this, but yet to receive a concrete answer.

 

Will test the output-on-record thing with the tellies and see if that makes a difference.


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