BMP4K colorspace/gamma interpretation in Resolve

Apologies if this is better suited for the Resolve subforum, but I am a little confused about color space and gamma settings for BMP4K Film mode footage in Resolve. The naming conventions for IDTs/LUTs/transforms/etc seem somewhat inconsistent.

In the Camera RAW settings, your only BMDFilm-based options are Blackmagic Design color space and Blackmagic Design Film gamma. However elsewhere in the program, there are settings that specifically refer to the 4K Pocket camera and these options are inconsistent between tools/color management systems. For instance, RCM has vanilla BMDFilm and Pocket 4K Film settings for both color space and gamma, but the Color Space Transform Tool only has a gamma setting that is specifically Pocket 4K while the color space settings are for vanilla BMDFilm or BMDFilm 4K (not specifically pocket). ACES also lacks a specific Pocket 4K IDT.

I haven’t gone in and done in-depth testing/comparisons between all the settings yet, but does anyone know what’s going on here? Are there actually settings that are missing or mis-named, or am I misunderstanding what’s going on under the hood? If If I’m only shooting and grading one camera/format it doesn’t matter that much, but I’m anticipating there being some issues if I start mixing BRAW, 4K Pocket Film ProRes, BMPCC CDNG, and BMPCC Film ProRes.

I'd love to hear an official answer, `cause yeah, it's a mess.

I believe the correct setting for output color space, where's there no Pocket 4K option, is "Blackmagic Design Broadcast Film".

Beyond that, RCM looks to be the only color management scheme with all the options available.

[CaptainHook]

Hopefully this will get cleaned up a bit in a Resolve update soon.

Blackmagic Design Wide Gamut Gen 4 is a common gamut with defined primaries that all our cameras can use (with raw files in Resolve you can choose Gen 4 for all our raw capable cameras). So that is why you can use "Blackmagic Design Broadcast Film" or "Blackmagic Design Pocket 4K Film" colour space/gamut interchangeably as John Paines points out since both of those cameras shipped with Gen 4 - but ideally these options will be consolidated to "Blackmagic Design Wide Gamut Gen 4" for colour space/gamut throughout Resolve.

In the RAW tab Resolve uses the generic "Blackmagic Design" colour space/gamut name with a colour science version/gen option (when available) and will always use the correct gamut for that particular camera. So with a Pocket 4K clip decoding into "Blackmagic Design" colour space with colour science version 4 is equivalent to "Blackmagic Design Pocket 4K Film" colour space. But as mentioned you can also use "Blackmagic Design Broadcast Film" colour space in RCM/CST since it's the same primaries. If you decoded any of our other cameras into colour science version 4 you could also use the same Pocket 4K/Broadcast RCM/CST colour space options.

Our gamma's are currently all specific to each camera as the log curves are specially tailored to the response of each camera/sensor. So you should always use the one labelled for the camera.

Thank you CaptainHook for being so attentive to questions regarding this subject matter in the forums. Greatly appreciated.

Thank you Hook for the clear answers.
Where do things stand at the moment in terms of ACES support for the 4K Pocket and Ursa Mini Pro with Gen4 color? Because the gamma curves are unique to each camera, then each one needs a unique IDT, right?

[CaptainHook]

Depends on the source file.

With DNG the information to linearize and the matrices to convert from sensor RGB to XYZ are all in the DNG metadata tags, so all the information needed to convert to ACES is always in the DNG and Resolve handles this internally.

Blackmagic RAW SDK 1.2 (in Resolve from v 15.2.2) added ACES gamuts (AP0 and AP1) and ACEScct (Linear was already available in 1.1) so from Resolve 15.2.2+ ACES is possible with Blackmagic RAW clips directly and through Resolves ACES managed timelines.*

For ProRes I'll be honest, I haven't looked at whats available in Resolve but will follow it up. But yes you need IDTs not only for each camera, but for each ISO. This is the same as other cinema cameras like ARRI etc. And prior to Gen 4 you would need IDTs for each colour temperature you shot with, as ARRI has available here for their linear files (you'll see in each EI/ISO folder multiple files for each CCT/correlated colour temperature):

https://github.com/ampas/aces-dev/tree/ ... i/alexa/v3

Its much easier to use ACES with RAW files where it's all handled internally in either Resolve or the SDK.



*It was also possible to manually do conversions with Blackmagic RAW 1.1 prior to this update as you could output as Linear XYZ and then do a simple transform from XYZ to one of the ACES gamuts and from Linear to whatever gamma (similar to what happens with the DNG flow), but the update removed the need for that step.

Excellent news CaptainHook regarding Resolve’s ACEScct with CDNG and BRAW. We have been using ACES correctly it seems without really understanding what’s going on under the covers.

Honestly, I have used ProRes 444 recently as well as CDNG 3:1 on the URSA Mini 4.6K Camera, but I won’t be using it (other than testing) on the BMPCC4K.


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Thank you for all the detailed answers Hook

Rick, I do not think the new Pocket 4K can shoot ProRes 4.4.4, only 4.2.2, up to HQ.
Cheers

Right! I was hopefully referring to my URSA Mini when I mentioned that.


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Thanks, Cap'n!

I´m a little bit confuse too because Resolve detect that is V4 in RAW tab, but if I tried to select in
timeline color space V4 is not posible because is not there. I got the last Resolve Studio Version

[CaptainHook]

I´m a little bit confuse too because Resolve detect that is V4 in RAW tab, but if I tried to select in
timeline color space V4 is not posible because is not there. I got the last Resolve Studio Version

Hi, as mentioned above any camera using Gen 4/Version 4 colour science is using the same gamut so you can use Blackmagic Design Broadcast Film / Blackmagic Design Pocket 4K Film interchangeable with any Gen 4 output. You will want to check "Use Seperate Colour Space and Gamma" and select the correct gamma for the camera you are using.

In the future we hope to add a "Blackmagic Design Wide Gamut Gen 4" option to make it easier for colour space and then just choose the correct gamma.

Thanks a lot for reply, everything clear right now

I´m a little bit confuse too because Resolve detect that is V4 in RAW tab, but if I tried to select in
timeline color space V4 is not posible because is not there. I got the last Resolve Studio Version

Hi, as mentioned above any camera using Gen 4/Version 4 colour science is using the same gamut so you can use Blackmagic Design Broadcast Film / Blackmagic Design Pocket 4K Film interchangeable with any Gen 4 output. You will want to check "Use Seperate Colour Space and Gamma" and select the correct gamma for the camera you are using.

In the future we hope to add a "Blackmagic Design Wide Gamut Gen 4" option to make it easier for colour space and then just choose the correct gamma.

If gamut is the same now for all cameras with v4 color science support, something like "Blackmagic Design Wide Gamut Gen 4" name feels more understandable for a first look. But in reality it may produce a lot of confusion like "Where is my Broadcast camera gamut gone when i click Use separate Gamma/Gamut ?" Probably it is better just add "Pocket 4K gamut" line to the CST tool to keep current logic and produce less questions from users. Especially Resolve CST already have some similar but duplicated gamuts with different names. For example Rec709 - sRGB gamut.

It is also would be great if you add that "Blackmagic Design Wide Gamut Gen 4 support" to ColorChecker Target Color Space list.

Hopefully this will get cleaned up a bit in a Resolve update soon.
Blackmagic Design Wide Gamut Gen 4 is a common gamut with defined primaries that all our cameras can use...

And what about non-Blackmagic cameras? For example, converting a timelapse from a Sony camera's raw files into DNGs for use in Resolve. When those DNGs are opened in the color tab only "Blackmagic Design" and "Blackmagic Design Film" are available. But I can find no information on that gamut or curve other than that the manual may allude to their similarity to Cineon. What does one pick to 'normalize' that gamut and gamma to 709 because nothing seems to match?

Thanks Cap'n.

[CaptainHook]

[And what about non-Blackmagic cameras? For example, converting a timelapse from a Sony camera's raw files into DNGs for use in Resolve. When those DNGs are opened in the color tab only "Blackmagic Design" and "Blackmagic Design Film" are available. But I can find no information on that gamut or curve other than that the manual may allude to their similarity to Cineon. What does one pick to 'normalize' that gamut and gamma to 709 because nothing seems to match?

"Blackmagic Film" for Gen 1 is actually not a transform but passes out sensor space, or sensor RGB. You can basically think of it as "no colour science applied". So you would need a transform from that particular sensors response to the gamut of your choice which you'd need to get from that manufacturer. I believe Digital Bolex for example offered LUTs to transform from their sensor RGB to common gamuts like 709 via a LUT to be used in this workflow with DNGs in Resolve.

For the gamma conversion you can use the regular Blackmagic Design Film transforms available via the CST plugin or RCM.

Thank you for the quick response. So in that "Camera Raw" tab in v. 15.3.1:

1. If I leave a "3rd party camera" DNG's color space transform debayering to the default 709, is Resolve using specific RGB primary information embedded in the DNG to map from that custom wide gamut to 709? As opposed to me changing it to "Blackmagic Design", which, as you mentioned, means I then have to manually remap the gamut with manufacturer-provided information? And if there is a technically-correct transform happening in the former scenario, then why not give us something like XYZ with known primaries to debayer to so we don't have to reverse-engineer the DNG?

2. If I set "Blackmagic Design" as my color space my only gamma option becomes debayering to "Blackmagic Design Film". This can be normalized to 709 via a simple CST node like you said, but (and it could be user error) in the CST selecting "Blackmagic Design Film" as my input gamma and then normalizing to output 709 does not appear to be a correct match to the "BM Design Film" I debayered to. For example: In version 1 I do a gamut and gamma normalization both to 709 and then create a new version. In version 2 I debayer to "BM Design" gamut and "BM Design Film" gamma. Since Resolve by default saves 'camera raw' info per version now, when I apply the above-mentioned CST to version 2 I should see a gamma, but not gamut, match to the 709-normalized version 1, correct? That's not the case.

3. It may be more productive for me to simply explain my intent: I'm trying to find a good workflow for taking Sony-shot timelapse sequences and generate a 'digital intermediate' from the raw still image sequence. My thought was, convert them all to DNG, open in Resolve, debayer to a wide gamut and cineon-style gamma, and then bake a ProRes master that maintains flexibility of the original in a smaller footprint. Is this something Resolve is suited for?

Thank you for the clarification. If it helps I can record a video.

Cap’n,
It seems Blackmagic Broadcast Film disappeared in the Color Space Transform EFFECT. It’s no longer selectable in DR16. What happened?

[CaptainHook]

Thank you for the quick response. So in that "Camera Raw" tab in v. 15.3.1:

1. If I leave a "3rd party camera" DNG's color space transform debayering to the default 709, is Resolve using specific RGB primary information embedded in the DNG to map from that custom wide gamut to 709? As opposed to me changing it to "Blackmagic Design", which, as you mentioned, means I then have to manually remap the gamut with manufacturer-provided information? And if there is a technically-correct transform happening in the former scenario, then why not give us something like XYZ with known primaries to debayer to so we don't have to reverse-engineer the DNG?

Yes, DNGs in the metadata provide the matrices and AsShotNeutral tags needed to convert from XYZ to SensorRGB (and back) as supplied by the camera manufacturer so Resolve will be converting from SensorRGB -> XYZ -> Rec709. As for getting an XYZ output option I'm not part of the Resolve team so you would have better luck requesting that direct to them, but you could use CST to go from Rec709 primaries to any other gamut as the output from the RAW decode should not be clipped.

2. If I set "Blackmagic Design" as my color space my only gamma option becomes debayering to "Blackmagic Design Film". This can be normalized to 709 via a simple CST node like you said, but (and it could be user error) in the CST selecting "Blackmagic Design Film" as my input gamma and then normalizing to output 709 does not appear to be a correct match to the "BM Design Film" I debayered to. For example: In version 1 I do a gamut and gamma normalization both to 709 and then create a new version. In version 2 I debayer to "BM Design" gamut and "BM Design Film" gamma. Since Resolve by default saves 'camera raw' info per version now, when I apply the above-mentioned CST to version 2 I should see a gamma, but not gamut, match to the 709-normalized version 1, correct? That's not the case.

Not sure I completely follow here (and being less tired while reading this may help my comprehension), could you take screenshots of your raw settings, CST, and the output you are getting?

Cap’n,
It seems Blackmagic Broadcast Film disappeared in the Color Space Transform EFFECT. It’s no longer selectable in DR16. What happened?

As mentioned above, it's consolidated into Blackmagic Design Wide Gamut Gen 4 (same thing). Resolve had their own reasons for not removing the Pocket 4K yet (also the same as Wide Gamut Gen 4) and leaving both in RCM.

My issue ended up most likely being that the DNG's weren't relaying the ISO data needed for Resolve to properly debayer to Blackmagic's log curve. Therefore, when I'd apply what I thought was a normalizing transform via a CST node, the result was off because that CST node expects ISO 800. Thanks CaptainHook for help figuring that out.

I was also made aware that with most raw formats, debayering to 709 is not a destructive process (neither gamut nor gamma is clipped), which seems to be the case with my raw DNG files, i.e. I can debayer to 709 then CST to a wider gamut and gamma. This doesn't seem to be the case with all raw flavors however. I also tested Canon's cinema raw light files from the C200 and the 709 debayer does clip the footage.

A bit off the original question, but hopefully still some helpful information.

Hopefully this will get cleaned up a bit in a Resolve update soon.

Blackmagic Design Wide Gamut Gen 4 is a common gamut with defined primaries that all our cameras can use (with raw files in Resolve you can choose Gen 4 for all our raw capable cameras). So that is why you can use "Blackmagic Design Broadcast Film" or "Blackmagic Design Pocket 4K Film" colour space/gamut interchangeably as John Paines points out since both of those cameras shipped with Gen 4 - but ideally these options will be consolidated to "Blackmagic Design Wide Gamut Gen 4" for colour space/gamut throughout Resolve.

In the RAW tab Resolve uses the generic "Blackmagic Design" colour space/gamut name with a colour science version/gen option (when available) and will always use the correct gamut for that particular camera. So with a Pocket 4K clip decoding into "Blackmagic Design" colour space with colour science version 4 is equivalent to "Blackmagic Design Pocket 4K Film" colour space. But as mentioned you can also use "Blackmagic Design Broadcast Film" colour space in RCM/CST since it's the same primaries. If you decoded any of our other cameras into colour science version 4 you could also use the same Pocket 4K/Broadcast RCM/CST colour space options.

Our gamma's are currently all specific to each camera as the log curves are specially tailored to the response of each camera/sensor. So you should always use the one labelled for the camera.

Cap'n,

Is this also true with the ACES Transform OFX? I've noticed that using ACES mode (via project settings) vs the Aces transform OFX (using BMD Film) yields different results for pocket 4K Braw clips. The only IDT's available are BMD Film, BMD 4K Film and then some other BMD Gen 3 options. Nothing specific for the pocket 4K or 6K.

[CaptainHook]

The ACES OFX plugin has probably not been updated, I'll check with the Resolve team.

Blackmagic Design Wide Gamut Gen 4 is a common gamut with defined primaries that all our cameras can use (with raw files in Resolve you can choose Gen 4 for all our raw capable cameras).

Hi, does it work the same for BMCC / BM Production Camera 4k?
Is it correct to set the Gen4 color for the CDNGs from Gen1 cameras?

[CaptainHook]

Yes, you can set Gen 4 for those cameras in the RAW tab. The choice is yours.

Cap'n,

Is this also true with the ACES Transform OFX? I've noticed that using ACES mode (via project settings) vs the Aces transform OFX (using BMD Film) yields different results for pocket 4K Braw clips. The only IDT's available are BMD Film, BMD 4K Film and then some other BMD Gen 3 options. Nothing specific for the pocket 4K or 6K.

I found a workaround for the issu of bmpcc4k /6k to solve the missing IDT issue, till there is an official IDT from BM I ll keep using this method in aces. Check it out if it will help:

I found a workaround for the issu of bmpcc4k /6k to solve...

Three transform nodes one after another seems a lot. Does it make clipping somewhere?

The CST and ACES OFX is all done in 32bit float so there should be no clipping.
But there's a much easier way — simply record in BRAW (or cDNG) and the IDT will be handled correctly automatically in ACES.