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ARRIRAW Questions
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Hi Robert,
thank you for your reply.
So a possible solution if/when Arri releases a 4K Alexa would be to use T-Link to say a Cineform based hardware solution that can intelligently compress the raw data?
As I said in my earlier post, handling uncompressed 4K (even if it´s “only” RAW) takes a lot of bandwidth and would be very unpractical and too expensive for a lot of productions.
Cheers,
Fredrik Harreschou
Colorist / online editor
Krypton Lab, Oslo, Norway -
Bob, I was under the impression that the D21 was 12 bit and the Alexa 14 bit internally. That’s why a 12 bit log RAW signal was created to keep all data in the signal for the Alexa.
Bastiaan
Resolve system:
MacPro 8 core 2010 – 16B memory
9TB harddisk (1 system disk, 8TB in software raid 0 for data)
Nvidea GTX285
Nvidea GT120
Blackmagic SDI Decklink
RedRocketcard.
Tangent Wave panel
Transvideo 15″ Cinemontor EvolutionAlso running it on a MacBook Pro 17″ (5.2)
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Hi Bastiaan,
I can’t comment on the internal specifics of the camera. If ARRI wants to output a different file, its certainly up to them to make those changes.
However, regardless of what the sensor’s ability is, as of today you are still using a 12-bit file.
bob.
Robert Monaghan, CEO
Glue Tools LLC
POBox 24124
Santa Barbara, CA, 93121
United Statestel: +1 805 456 7997
fax: +1 805 456 7998 -
The current 2880×2160 files that a D-21 generates are about 12.4Megs, if they are unpacked. There is a packing method that would drop it well under 10Megs. Codex and S.Two both provide this packed file format.
I can’t say what the best solution is for compressing the sensor data. But I will say this: There is a lot of R&D to be done in this area. Red’s patent is pretty specific to their camera, and the way it works with its Log space. There are many other ways to do compression.
I think that we will see others work on this. Perhaps someone will even to provide an “open” system for compression. (This is key.. as we don’t want to be forced to rely on a proprietary system, 30 years from now, of a company’s proprietary and secret format that no longer doesn’t exist.)
For now, ARRI has a great RAW solution that is very good for 99% of the shots a production uses and is very much in line with HD sized DPX files. (And 30 years from now, you can still open them and use them. No proprietary compression or encryption.)
bob..
Robert Monaghan, CEO
Glue Tools LLC
POBox 24124
Santa Barbara, CA, 93121
United Statestel: +1 805 456 7997
fax: +1 805 456 7998 -
Great points on using open formats, Robert. I really agree. It will be interesting to see what the other players come up with.
I think the issues with storing RAW is just dawning on producers and DPs. Like you say, how do we make sure that it is possible to open up the proprietary files in the future.
The best would be if there was an industry standard set by a committee.
Cheers,
Fredrik -
[Fredrik Harreschou] “The best would be if there was an industry standard set by a committee. “
I cannot disagree enough with that statement.
Committees have given us the wonderful world of MPEG/ HDV/ MXF/AVCHD where any and a bazillion variations to work with, rather than defining ONE.IMHO committees tend to placate the masses rather than define structure to last for eternity
The are any number of existing structures for archive and delivery.
Today
DPX can do a lot of things, however OpenEXR or the Academy IFF proposals offer future proofing with far more robust metadata controls and maintenance. I don’t understand why Adobe does not do more with their DNG format.gary adcock
Studio37Post and Production Workflow Consultant
Production and Post Stereographer
Chicago, ILhttps://blogs.creativecow.net/24640
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Hi,
my point wasn´t the committee part, but a common, open format with a future, as opposed to a dozen proprietary formats.
OpenEXR is great and evolving into a superformat. Adobe has CinemaDNG but does anyone actually use it?
Cheers,
Fredrik -
Actually, I want to correct myself… 🙂
Yes, the Alexa sensor does do 14 bit. Yes, the 12-bit ARI file will reproduce 16-bit data if the appropriate process is used to convert from 12-bit to 16-bit.bob.
Robert Monaghan, CEO
Glue Tools LLC
POBox 24124
Santa Barbara, CA, 93121
United Statestel: +1 805 456 7997
fax: +1 805 456 7998 -
Interesting…
Doesn´t that imply that it in fact is not a direct “raw” data readout? True raw from a 14 bit sensor should be 14 bit, right? There has to be some “rounding off” to get the 14 bit raw into a 12 bit container, will it not?
Not sure how to interpret this statement: “Yes, the 12-bit ARI file will reproduce 16-bit data if the appropriate process is used to convert from 12-bit to 16-bit.”
I understand that we can decode at higher depths, but what do you mean by “reproduce 16 bit data”? Do you mean “produce”? 😉
Best,
Fredrik -
Typically many camera manufactures will use a curve to take the sensor data (14-bit, or even 12 bit, for instance) to selectively remove parts of the image data. The results are then stored, compressed, etc. (I suspect Red works this way, and I know that some Phantom Cameras work this way, for instance.)
To reconstitute the data, the reverse version of the curve is applied, to generate the new image. Afterwards a series of steps (the “Color Science”) is performed. Actually, the curve that is used to reconstitute the data is often specialized color science, as well. Many cameras use this technique right now.
To answer your question: “Produce or Re-produce”. The fact that the image is Bayer Pattern, means that regardless of your bit depth, you are still missing 2/3rds of your initial data. So 12 bit or 16 bit is just more missing data. The 12-bit isn’t 12-bits of color. Its 4096 values. Those values could be 4096 “32-bit” pixels. Or 4096 “8-bit values”.
Once “Produced/Reproduced”, the color processing steps really change the way this original sensor image looks like, anyways. The process that is used to take a Bayer Pattern Image and convincingly creates an RGB image is simply amazing. The amount of applied science and creative mathematics is astounding.
Interestingly “FYI” , the human eye is about 12-bit, anything higher is visually imperceptible. Only VFX people find that the 14-16 bit data is really needed for their work.
Hope this helps.
Bob.
Robert Monaghan, CEO
Glue Tools LLC
POBox 24124
Santa Barbara, CA, 93121
United Statestel: +1 805 456 7997
fax: +1 805 456 7998
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