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Canon 5D 2K raw feed update - 1920x720 possible on 1000x card?


Andrew Reid
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I wonder if they can feed it to the jpg compression engine in the camera? Proably lots of this stuff is not possible without complete documentation and ability to program digic fully though. The jpg processor probably has 8bit limit too.

 

I think the problem is doing a high quality debayer on the raw. The compression to JPEG isn't the processor intensive bit. It is the debayering.

 

All the camera has to do for DNG is dump the 1s and 0s to a very fast 512MB buffer memory chip. Then write 512MB to the card (that takes longer).

 

Imagine with every DNG file having to process all that data - 5MB of it - like opening a raw file in Photoshop - but in-camera.

 

Clearly the camera is doing a very simplistic debayer of the 2K raw to provide an image for live view and the H.264 encoder.

 

But we need a much higher quality one for decent 1080p MJPEG, otherwise you may as well stick with the existing H.264.

 

That's my understanding of it.

 

DNG is the option with the least processing, least CPU intensive, but sadly the most data to shuttle off to the card.

 

Of course Blackmagic cameras debayer their 2K raw just fine to ProRes in-camera, even the Pocket Cinema Camera. So it is doable with today's technology. What Blackmagic are doing could be very specialised though. Whether Canon have that technology, I don't know.

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Reading up on all the Andromeda stuff and asking people on Twitter what they know.

 

Apparently RealStream were under NDA when they got bought out.

 

It seems whoever bought RealStream did not want to be outed.

 

"Why" - that is the million dollar question isn't it...

 

Seriously you wouldn't believe what kind of dodgy stuff goes on out there. I know people who have worked at the top of large companies. No matter what the reputation, there's a ton of dark stuff that goes on. I know it for a fact.

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Andromeda was good - however I doubt it was anything near the BMCC even though the BMC doesn't have the same color information - the base iso of the DVX was sub 100 and it didn't have the same DR - we are talking about a 10 year old camera here.

 

Don't confuse the DR of what was recorded to DV for the native capabilities of the chip.  They achieved 9.5 stops which is on par or better than what we have with the GH2 (according to Shian Storm we're only getting an effective 6 stops in video mode, regardless of manufacturer's claims).  Comparing it to the BMCC might be a bit of hyperbole on my part but noiseless (reported by actual Andromeda users) high DR, highly gradable images...the BMCC is the only comparable camera out there.  

 

Folks have used Andromedas as b-cams with their RED.  The age of the camera isn't that important when you forget about what Panasonic sold as an implementation and concentrate on what the modification actually provided.

 

Also, base ISO was not sub-100.  It reacted non-linearly but under normal circumstances it was around 400 ASA (others assumed 320) in progressive mode yet under extremely bright light, requiring f/16 it performed like its base ISO was 1000 ASA.

 

edit: the evidence, along with the GH1 and GH2, shows a pattern at Panasonic of releasing implementations that fall far short of what their baseline technology, the chip itself, is natively capable of. 

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That's very far from the current consensus.

 

1920x720 is under the date rate that a 1000x CF card can do, so should be possible. You can see my next blog post, there's a LOT of stuff in that. I won't reveal too much until that is online, but already the 1920x1285 14bit raw is very usable as a 30fps 1 second burst mode like the Nikon V1. Rendering my sample clips as we speak.

 

Bear in mind also that is still very early days with this. Lots of progress is in the pipeline just takes time.

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That's very far from the current consensus.

 

1920x720 is under the date rate that a 1000x CF card can do, so should be possible. You can see my next blog post, there's a LOT of stuff in that. I won't reveal too much until that is online, but already the 1920x1285 14bit raw is very usable as a 30fps 1 second burst mode like the Nikon V1. Rendering my sample clips as we speak.

 

Bear in mind also that is still very early days with this. Lots of progress is in the pipeline just takes time.

 

I thought the buffer has a write speed limitation though, independent of the card?  I guess you'll find out if you keep sticking faster cards in there and performance plateaus.  

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Write speed of the buffer is definitely no problem. It is able to continuously capture the 14bit raw stream from the sensor even in 3.5K mode. It is not as simple as sticking different cards in there and finding out where performance levels off. There's more variables here than card speed. All sorts of as mysterious internal Canon code, debayering, live view stuff, etc. I'll leave it to the Magic Lantern devs, they know far more than me on how to proceed.

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