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Australian Image (Ray)

Blackmagic Camera HDMI Output

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I'm posting this here in case there are some technically clued up members that might be able to answer my question. First off, I posed this to Blackmagic, but my email was redirected to the Melbourne, Australia, support centre who basically repeated what's already generally available on the Blackmagic website, which doesn't answer my question.

What I don't understand is why the BMPCC4K (and 6K I gather) can't output a 4K signal from the HDMI port. Blackmagic themselves say that it's a HDMI 1.4 standard port (which came out in 2009) and is therefore technically 4K compliant.

Despite this, it is only able to output a 1080p signal. Now what perplexes me is that non-Blackmagic cameras such as the Panasonic EVA1, Canon’s C300 MK II, Sigma FP and whatever else, are able to output not just a 4K signal to the VA, but also have the VA record in BRAW. There are other cameras such as the Z-Cam that can output not only 4K but the likes of ProResRAW over HDMI to a suitable recorder such as the Atomos Ninja V.

So my question is why this seeming anomaly when it comes to the BMPCC4K/6K?

 

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3 hours ago, Australian Image (Ray) said:

I'm posting this here in case there are some technically clued up members that might be able to answer my question. First off, I posed this to Blackmagic, but my email was redirected to the Melbourne, Australia, support centre who basically repeated what's already generally available on the Blackmagic website, which doesn't answer my question.

What I don't understand is why the BMPCC4K (and 6K I gather) can't output a 4K signal from the HDMI port. Blackmagic themselves say that it's a HDMI 1.4 standard port (which came out in 2009) and is therefore technically 4K compliant.

Despite this, it is only able to output a 1080p signal. Now what perplexes me is that non-Blackmagic cameras such as the Panasonic EVA1, Canon’s C300 MK II, Sigma FP and whatever else, are able to output not just a 4K signal to the VA, but also have the VA record in BRAW. There are other cameras such as the Z-Cam that can output not only 4K but the likes of ProResRAW over HDMI to a suitable recorder such as the Atomos Ninja V.

So my question is why this seeming anomaly when it comes to the BMPCC4K/6K?

 

Hi Ray,

Do you need to record externally over HDMI for some reason? Or is it just to output UHD?

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Since I now have the VA 12G HDR, I thought I'd try and make the most of its capabilities and do backup recording as well. I don't mind so much if I can't do BRAW (though I'd like that, say recording 5:1 on the camera and 12:1 on the monitor), but not being able to do 4K ProRes is a bit perplexing (and disappointing).

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Being able to punch-in to 1:1 to its native 4K on an external 7" daylight viewable monitor would be very handy...yeah this limitation is really strange on this cam, probably to keep costs down or to re-direct some sales to the UMP family...

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12 minutes ago, Tommaso Alvisi said:

...probably to keep costs down or to re-direct some sales to the UMP family...

I don't know if this has anything to do with cost or sales (people would probably jump onto the VA for 4K and/or BRAW recording with their BMPCC4K/6K). The HDMI 1.4 standard which supports 4K came out nearly a decade ago and the HDMI 1.3 standard which supports 2K came out 14 years ago.

So by the time the BMPCC4K/6K were in the design stages, the hardware for supporting HDMI 1.4 should have been something that everyone used. And I've always heard that Blackmagic doesn't cripple any of their systems if something is able to be provided, so this limitation really does baffle me.

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Which kind of connection do they use doesn't mean anything...

Using DSP and ASICs inside to be able to handle 4K output (and also certify the signal path for the added required bandwidth) is a cost...in a camera which costs already half of what other cams with the same sensor...and with an included 5" monitor too...

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2 minutes ago, Tommaso Alvisi said:

Using DSP and ASICs inside to be able to handle 4K output (and also certify the signal path for the added required bandwidth) is a cost...in a camera which costs already half of what other cams with the same sensor...and with an included 5" monitor too...

Granted, I don't know much about this, but given that the camera is already designed to output 4KDCI to an internal and external source, I would have thought that integrating the HDMI to export at least 4K would have been par for course.

 

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As already mentioned above, the cameras other internal hardware limit the data rate we can put to the HDMI out (bandwidth and firmware limitations can be dictated by other hardware in the camera, not just the output port). We also have the limitation in those cameras that we can't do ProRes 444 and have to stick to Prores 422HQ as the highest quality ProRes option for similar reasons; limitations in hardware/bandwidth/etc.

The cost of adding hardware to support this would put the price into a completely different category (not to mention generate more heat and use more power) and those things are always weighed up in the decision making - while 4K output and ProRes 444 will make a difference to some people - will it make a difference to the majority of users the camera is aimed at? If not, we can put the camera at a much more affordable price point. Sometimes tough decisions like that are made to reach a target price point, especially if we have other products in the line that may be better suited anyway. And then sometimes the cost of hardware (and its power/heat effeciency) comes down over time and we can introduce new models that add features that were previously not cost effective. But as you say, we don't like to limit our products and try cram everything we can in there. But we don't always get everything we want in there either because you have to be practical at the end of the day.

Its the usual story for any hardware manufacturer of any product.

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We don't normally discuss such things so it's not surprising you wouldn't be able to find an answer. But its fairly generic information that anyone in manufacturing products would deal with, so hope it helps.

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I'm hoping that I might be able to pass on a small issue that I have with my BMPCC4K and VA 12G HDR 5". I have the camera set 24fps normally and HFR set to 75fps. The VA sees the 24fps, but when I press the HFR button nothing changes. If I set the off-speed setting to 60fps and then press the HFR button, the VA speed stays at 24fps.

However, if I change the frame rate on the screen (by touching the 24 symbol) to 60fps, then the VA goes to 60fps. This is a bit annoying, as now the HFR button becomes useless, as I can't quickly change from normal speed to high speed via the HFR button and have the VA respond accordingly.

I would have contacted Blackmagic via email, but it seems these emails are all redirected to the local Australia rep who isn't placed to comment on these sorts of issues.

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