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Author Topic: 8-bit Video in a 10-bit Wrapper  (Read 9908 times)
JB Rasor
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« on: April 11, 2014, 12:52:55 AM »
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With the Sony A7s vs. Panasonic GH4 debate gearing up, I wanted to get some guidance from the members about a particular quirk...oversight, or however you'd like to phrase it, with regards to the A7s.
I am pretty new to the video world, so forgive my basic inquiry, but I've searched the hell out of this question and can't seem to get a solid answer.

The A7s outputs an 8-bit 4:2:2 signal (hoping this is the correct terminology) via mHDMI. Ideally one would be running the new Atomos Shogun recorder, which records in either 10-bit 4:2:2 ProRes or Cinema DNG raw. So what flexibility or advantage have you gained by recording in a 10-bit 4:2:2 codec, but only outputting 8-bit from the camera? Essentially 8-bit video in a 10-bit wrapper.   

Is it like it was natively recorded at that bit rate? No difference at all?

I know the details of the process are pretty technical, but hell, it's a photography forum so bring it on Smiley

Thanks everyone for your help. Have a great weekend!!

JB
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Sareesh Sudhakaran
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« Reply #1 on: April 11, 2014, 07:11:30 AM »
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The A7s outputs an 8-bit 4:2:2 signal (hoping this is the correct terminology) via mHDMI. Ideally one would be running the new Atomos Shogun recorder, which records in either 10-bit 4:2:2 ProRes or Cinema DNG raw. So what flexibility or advantage have you gained by recording in a 10-bit 4:2:2 codec, but only outputting 8-bit from the camera? Essentially 8-bit video in a 10-bit wrapper.   


None whatsover. The same applies to a camera that records to 4:2:0 internally but sends out a 4:2:2 signal.
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michael
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« Reply #2 on: April 11, 2014, 07:27:51 AM »
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The advantage that you gain is indirect. It's like loading a 12 or 14 bit stills image into a 16 bit workspace. You aren't increasing the bit depth, but you are enclosing it in a larger container. This has some (small) advantages when it come to grading as the data is not constrained by the boundaries of a smaller space.

Michael


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JB Rasor
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« Reply #3 on: April 11, 2014, 04:48:09 PM »
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Thanks guys. With the rumored price tag of the Sony A7s I think my descision got a lot easier. I love the capability of the GH4 but I've never used M43'rds before and was a little nervous about getting into it head on. But that may just be my move.

JB
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JB Rasor
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« Reply #4 on: April 17, 2014, 01:39:43 PM »
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I have a question Michael...and other members into video tech as well.
The Atomos Shogun records Cinema DNG raw. Does the camera also need to be able to shoot raw video, in order to record Cinema DNG to the Atomos, or can you record raw data from any camera onto the Atomos? I'm assuming the former is the case but I wasn't sure.


  
« Last Edit: April 17, 2014, 01:42:37 PM by JB Rasor » Logged
michael
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« Reply #5 on: April 17, 2014, 03:00:43 PM »
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I have a question Michael...and other members into video tech as well.
The Atomos Shogun records Cinema DNG raw. Does the camera also need to be able to shoot raw video, in order to record Cinema DNG to the Atomos, or can you record raw data from any camera onto the Atomos? I'm assuming the former is the case but I wasn't sure.


No, the camera itself has to output raw. The Panasonic GH4, for example, can output 10 bit 4:2:2:, which is still photography terms is like outputting a 14 bit TIFF. Tons of detail, little lost, but still not raw.

Funny thing is, many people with raw capable video cameras are using them with Prores, because raw video workflow is still a bit of a horror.

Michael
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JB Rasor
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« Reply #6 on: April 17, 2014, 11:08:37 PM »
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Thanks Michael! That was what I thought but wasn't entirely certain. I guess the storage issues associated with raw are tough.

Unfortunately the 10-bit 4:2:2 output of the GH4 can only be recorded externally. But that's part of the trade off. Still a great camera by all accounts.

Thanks again,
JB
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paul ross jones
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« Reply #7 on: July 06, 2014, 04:24:17 AM »
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The advantage that you gain is indirect. It's like loading a 12 or 14 bit stills image into a 16 bit workspace. You aren't increasing the bit depth, but you are enclosing it in a larger container. This has some (small) advantages when it come to grading as the data is not constrained by the boundaries of a smaller space.

Michael




i have been able to grade heavier when hit with a grading problem with a 8 bit tiff when i convert it to 16 bit (like banded sky). a retoucher told me he thinks that photoshop makes up gradients to fill the bit depth, not sure if it does, but it does work. obviously not nearly as well as working off a native 16 bit tiff.

paul
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bcooter
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« Reply #8 on: July 11, 2014, 12:30:06 PM »
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Raw or baked in, I guess it depends on the project.

Me . . . I want our dailies to have the closest look possible to finish and I love it when we have to produce dailies and proxy's from the RED vs. any baked in look.

The RED's with the Red Rocket and the newest cinex make a great workflow for us, using Cinex or Resolve to set a file, copy the look, paste it onto a bunch of files and let it rip.

But I love Resolve, especially with the Rocket card because it runs real time or faster.  

I did this in Resolve, from dailies to proxy's to finish (minus the flash which was in the NLE) and the client didn't have to make a leap and ask what is it going to look like.



For file size, well, all files today are big, though nothing is larger than 442 pro ress as in 2k it's almost as big (may be larger) than a RED 4k raw file.

I think a lot of people fail to recognize that everyone works differently, everyone rolls their own in workflow and style.

Red catches a lot of heat . . .  some they deserve, most the don't, but their business model allowed me to buy three real cinema cameras for less price than one Arri and btw I think Arri makes a very nice camera.

IMO

BC

PS.  Speaking of large file sizes I had a European ad agency request a long clip in uncompressed proress, the file was huge even in 2k, and we have fast load times in our London space and it still took 12 hours for it to go up probably about 4 to 5 hours to download, which was funny because the final video they edited was for mobile only.
« Last Edit: July 11, 2014, 12:33:30 PM by bcooter » Logged

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