Blackmagic Forum

Hello folks!

As you know, Alexa will be able to shoot raw internally. Also it can record 2K prores, which is a really cool feature imho, so I wanted to know is there anybody expecting a future firmware upgrade for BMCC which brings an ability to shoot 2K ProRes.

I am wondering that because as you know processing raw is still not that easy. In october I worked on British feature The Two Faces on January, as a part of ACs on Turkish crew and we shot it 2K ProRes. I believe it makes post production lighter a lot...

What do you think?

+1

I think the ProRes Film Log mode is currently being overlooked in favor for RAW when it would be perfect for most jobs.

The size difference is really minimal tho. 128 pixels wider and 72 pixels higher.

HD 16x9 = 1920×1080 pixels
2K 16x9 = 2048x1152 pixels

Why not go directly to 2.5K ProRes as well, while at it?

And I agree, that the ProRes Film log is great.

Roland Öller wrote:Why not go directly to 2.5K ProRes as well, while at it?

And I agree, that the ProRes Film log is great.

Hello,

I'm courious if it was technically possible to code a RAW image directly into ProRes4444 without de-bayering it first?

Means:
Coding the bayer-patterned RGB samples according to ProRes4444 by ignoring the gaps
and assembling what could be referred to as ProResRAW

Of course, Apple would need to standardize this (if technically possible&reasonable)
and add de-bayering to the ProRes component.

Best regards,
Bernhard

Bernhard wrote:

Roland Öller wrote:Why not go directly to 2.5K ProRes as well, while at it?

And I agree, that the ProRes Film log is great.

Hello,

I'm courious if it was technically possible to code a RAW image directly into ProRes4444 without de-bayering it first?

Means:
Coding the bayer-patterned RGB samples according to ProRes4444 by ignoring the gaps
and assembling what could be referred to as ProResRAW

Of course, Apple would need to standardize this (if technically possible&reasonable)
and add de-bayering to the ProRes component.

Best regards,
Bernhard

Such a thing is possible already with Cineform Raw - considering it apparently requires less computational power to encode and it has a great compression ratio - it would probably be a better bet (if any) than a yet to be invented prores codec.

Tom wrote:

Bernhard wrote:

Roland Öller wrote:Why not go directly to 2.5K ProRes as well, while at it?

And I agree, that the ProRes Film log is great.

Hello,

I'm courious if it was technically possible to code a RAW image directly into ProRes4444 without de-bayering it first?

Means:
Coding the bayer-patterned RGB samples according to ProRes4444 by ignoring the gaps
and assembling what could be referred to as ProResRAW

Of course, Apple would need to standardize this (if technically possible&reasonable)
and add de-bayering to the ProRes component.

Best regards,
Bernhard

Such a thing is possible already with Cineform Raw - considering it apparently requires less computational power to encode and it has a great compression ratio - it would probably be a better bet (if any) than a yet to be invented prores codec.

Isn't this like the 10bit 4k compressed raw canon talked about for the C500 or am I way off?

Sam Tansey wrote:

Tom wrote:
Such a thing is possible already with Cineform Raw - considering it apparently requires less computational power to encode and it has a great compression ratio - it would probably be a better bet (if any) than a yet to be invented prores codec.

Isn't this like the 10bit 4k compressed raw canon talked about for the C500 or am I way off?

No idea, Cineform RAW is 12 bit and is bayer footage (as in, not yet debayered). Ive been encoding the bmcc dng sequences into cineform Raw and it seems to have the sharpest debayering algorithms - not to mention its fast and compresses well.

Tom wrote:

Sam Tansey wrote:

Tom wrote:Ive been encoding the bmcc dng sequences into cineform Raw and it seems to have the sharpest debayering algorithms - not to mention its fast and compresses well.

Tom what is your workflow? What software are you using for the transcode? Cineform Studio Premium?

adamroberts wrote:
Tom what is your workflow? What software are you using for the transcode? Cineform Studio Premium?

Yes, Cineform studio Premium.

Drag the folders into the studio import program, transcode them to cineform raw. I usually only tweak the debayering and occasionally the white balance via the metadata - then in bring them into resolve for colouring. I usually master the final clips into Cineform filmscan1 or filmscan2 in non raw mode at the end.

What I like about it is that once ive converted the dng's into cineform raw, I can delete them but still retain most of the benefits of the raw format - but at a fraction of the file size..

One of the pool shark dng sequences as a cineform raw file:
https://docs.google.com/file/d/0BytMyjm ... sp=sharing


The only thing ive done is change the debayer method. It is still ungraded.

2k or 2.5k ProRes would be awesome. I am already starting to lean more towards shooting ProRes film log for most projects.

Tom wrote:

No idea, Cineform RAW is 12 bit and is bayer footage (as in, not yet debayered). Ive been encoding the bmcc dng sequences into cineform Raw and it seems to have the sharpest debayering algorithms - not to mention its fast and compresses well.

Tom, do you have any issues with metadata from raw files surviving the conversion into Cineform?

Yes, while it can shoot 2.5k RAW why not it shouldn't be able to shoot 2,5k ProRes as well...

Btw, Tom, are you using cineform on apple or windows?

Check the bmcuser forum. I believe this topic has been discussed there. I am really not an expert on this but as far as I know it is important to understand that "Raw resolution" isn't the same as debayered resolution.

From the camera's 2.5k Raw image you can get a real 1920x1080 resolution 422 image. It's not possible to debayer 2.5k into 2.5k pro res 422. You actually need the extra resolution for the color information.

I believe this is the same reason why you can't get a 4444 image out of the camera.

I might be mistaken here but I believe the bottom line is: It's not possible.

On the other hand I would like to ask, what do you need 2k oder 2.5k for? I believe for most of our distribution we will downres to 1080, 720 or any way. If it's about a slight cropping then just crop the 1080 image a up res afterwards. I have seen a lot of people doing this with alexa 1080 footage e.g.

teh wrote:Check the bmcuser forum. I believe this topic has been discussed there. I am really not an expert on this but as far as I know it is important to understand that "Raw resolution" isn't the same as debayered resolution.

From the camera's 2.5k Raw image you can get a real 1920x1080 resolution 422 image. It's not possible to debayer 2.5k into 2.5k pro res 422. You actually need the extra resolution for the color information.

I believe this is the same reason why you can't get a 4444 image out of the camera.

I might be mistaken here but I believe the bottom line is: It's not possible.

On the other hand I would like to ask, what do you need 2k oder 2.5k for? I believe for most of our distribution we will downres to 1080, 720 or any way. If it's about a slight cropping then just crop the 1080 image a up res afterwards. I have seen a lot of people doing this with alexa 1080 footage e.g.

maybe for a full length feature film? for a really independent one...

teh wrote:Check the bmcuser forum. I believe this topic has been discussed there. I am really not an expert on this but as far as I know it is important to understand that "Raw resolution" isn't the same as debayered resolution.

From the camera's 2.5k Raw image you can get a real 1920x1080 resolution 422 image. It's not possible to debayer 2.5k into 2.5k pro res 422. You actually need the extra resolution for the color information.

I believe this is the same reason why you can't get a 4444 image out of the camera.

I might be mistaken here but I believe the bottom line is: It's not possible.

On the other hand I would like to ask, what do you need 2k oder 2.5k for? I believe for most of our distribution we will downres to 1080, 720 or any way. If it's about a slight cropping then just crop the 1080 image a up res afterwards. I have seen a lot of people doing this with alexa 1080 footage e.g.

Chroma sub-sampling and bayer resolutions are completely different things and mixing up the two can lead to a long and detailed argument online (seen it happen sooo many times )

You can indeed get a full image without any chroma-subsampling with the bmcc in raw mode. Having enough photosites in order to have x1 R x1 G x1 B pixel when rescaled down to a set resolution is a different issue to sub-sampling the chroma channels. The two should not be interchanged or compared. They are in some ways related to the overall image at the end of the process - but its important to distinguish the two.

Chroma sub-sampling is taking information away for compression/data rate purposes. Oversampling a bayer sensor in order to have one of each colour per pixel is different. It is true that the BMCC does not have a high enough resolution sensor to have 1 RGB photosite per HD resolution pixel - but depending on how the bayer data is processed and debayered makes a big difference on the actual final quality of the colour channels.



In answer to the other questions regarding Cineform Raw:

I use a PC, ive not had any problems with meta data throughout the process....yet. If you do have problems, contact cineform, their support staff are great.

So Tom,

Am I right in thinking then that when I use Studio Premium to convert my DNGs to Cineform RAW I shouldn't be selecting to keep the footage at 2.5K but should in fact downscale to 1080?