Resolve Color Management & Raw Footage

Resolve Color Management & Raw Footage

September 11, 2015

Resolve Color Management (RCM) is powerful workflow tool but using it with Raw footage can be slightly confusing. Learn more in this Insight


A Potentially Confusing Twist To The RCM Workflow

In my overview Insight On Resolve Color Management, several members commented that when working with Raw footage things weren’t working as they expected – namely that the Input Color Space control didn’t do anything to transform footage.

In my previous Insight, I showed the RCM workflow with a ProRes clip where Input Color Space did indeed transform or assign a color space of a clip(s) in the media pool.

Since I was just getting acquainted with RCM, I didn’t dive into other managed workflows including working with Raw footage.

When I read the comments in the previous post about Raw & RCM I was intrigued.

While I had a pretty good idea of what was going on, I needed to do some testing and some more research.

This Insight is to explain those findings in a bit more detail.

Once again a big thanks to my good pal & friend of MixingLight Juan Salvo for listening to my seemingly non-stop ramblings about RCM and Raw workflows &  providing some clarity on some of the finer details of what’s going on behind the scenes in the image processing pipeline.

If you missed Juan’s thoughts on RCM check out that First Look Insight.

It’s Raw Not Video!

As the comments detailed in my previous Insight and my own quick test confirmed, assigning an Input Color Space to a Raw file (.r3d, .ari, .dng) doesn’t do a thing.

But to understand why that it is we need to address a couple of things:

First, as you probably know Raw is just data/information – it’s not video per se.  But the thing is, the colorimetry of a Raw file is a well-known quantity.  Software developers and apps like Resolve know exactly the colorimetry of an Arri Raw, Red or Sony Raw shot.

Because of this, the input color space assignment is simply not needed and redundant.

On the other hand, with a video file, the colorimetry could be anything.

For example, a ProRes file could be in Rec 709, Rec 2020, Log C, or any other color space.  Just because its ProRes doesn’t mean color space and gamma information is explicit.

Resolve does a very good job most of the time of guessing the colorimetry details of video files in a non-managed workflow, but with RCM you have the ability to be explicit about how that file should be handled on input by changing the Input Color Space for any clip(s).

The Input Color space allows you to assign or reassign a color space to a clip based on what’s ‘right’ for a particular clip(s).

Again, with Raw footage because of the availability of SDKs by each camera manufacturer, Resolve knows exactly how to handle that data on input.

So, what happens with RAW in an RCM workflow is that Resolve processes the Raw data automatically for you into your timeline/output color space, and it does this with very high precision preserving all of the Raw image data via a computational transform.

Next, in both managed and non-managed workflows, you have a lot of control over the quality of Raw processing (debayering) and of course, you have access to Raw controls to massage a shot to your liking.

But with some Raw Formats like RED or Cinema DNG where you can assign color space and gamma settings for the Raw footage in the Raw panel, you don’t have those controls (grayed out, or not functional) in an RCM workflow because Resolve is automatically handling that processing for you.

RCM still works with Raw footage and as I’ll show you in the video, it’s just a different approach to how you’ve probably worked before in a non-managed workflow – and just like I mentioned in my previous Insight, you’re under no requirement to work with RCM!

Getting To A Starting Point (RED Is Just A Bit Different)

When it comes to Raw, many colorists just want to get to a good starting point for the rest of their grade.

We’ve talked in other Insights about Raw parameters as being ‘development’ tools.

So maybe you like Red Color 4 and Red Log Film for .r3ds or with BMD DNG files you like working with BMD film or you like starting with a LOG C file for Alexa.

With RCM and Raw, you can get to these starting points quite easily by using the Output Color Space control and by using the timeline color space to adjust how controls feel and how your grades are processed.

For example, if you have an Arri Raw file and you like as a starting point LogC, but you like ‘normal’ REC 709 interaction with the grading controls, simply set up your Timeline Space to Rec 709 Gamma 2.4, and your Output Color Space to Log C and it’s just like working with a ProRes LogC shot.

Furthermore, LUTs can work in an RCM workflow but because a LUT processes the image in the working (Timeline Color Space) you have to exercise a little care (and make decisions ahead of time) about your Timeline Color Space setup – I’ll show you what I mean in the video below.

Finally, RED has always been a bit different – the .r3d controls in Resolve have a lot of power, but RED does a lot of unique things in their SDK that developers – including the Resolve team – don’t have access to.

Remember how I mentioned Red Log Film?

You’ll notice that it’s missing from any of the color space pulldowns (Cineon Film Log is a close match). This is because Red Log Film is unique processing from RED.  There are workarounds, but yes, right now specifically with Red and RCM, there aren’t 1 to 1 equivalents with how you may have processed .r3ds in the past.

Next Steps?

As you can probably tell from this and my previous Insight I’m really excited about the possibilities of RCM, but I’m still learning all of the implications of using it on real-world projects.

So while this Insight hopefully clears up some issues regarding Raw and RCM it’s not meant to be definitive.  I’m very interested in your own experiences.

Please use the comments below to share your thoughts.  

– Robbie

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Comments

14 thoughts on “Resolve Color Management & Raw Footage”

  1. In a color managed project if you clip out the highlights in the raw tab and you bring them back in a node? I don’t think you can in a non color managed project. If you can bring them back are the raw settings useless because the primaries have full control of all the raw data?

    If you put a BM4k film raw file into logc managed color space does resolve remove and sensor specific color biases form the BM camera to match an alexa’s sensor color biases? For example would the BM footage get that same alexa green tint?

    1. Raw settings aren’t useless. They’re still a convenient and precise way to adjust color temp and exposure. The optional processing are still available.

      As to whether a bm camera would match the Alexa. In as much as it can, yes. The transform (if its computationally correct… And these things do sometimes have bugs) should transform the bmd film type log to an Alexa LogC type log. But that doesn’t mean the camera itself wil be able to capture as much information as the Alexa. As to the green cast.. If you mean the Alexa “look”, that’s part of the photo matrix transform, and that RCM doesn’t do.

  2. Huge thanks for breaking don the RAW workflow, as Ive been doing RED nonstop. Im very disappointed they didnt include a transform for RedLogFilm, as the newer RED cameras can record ProRes and I occasionally get a flattened ProRes444 RedLogFilm to grade. I requested it, but I now see why it wasnt added. As you mention, Ive been using Cineon Log as a close alternative. Still, fingers crossed

    RCM seems fantastic for some aspects, but difficult for others. An example is VFX, which usually require provided DPX openEXR sources and delivery even if shot RAW. Ideally, I could somehow use RCM on some shots & use a completely unmanaged approach (as opposed to converting the entire timeline working space & output) for others, but that brings in a matching issue between the SDK debayer and RCMs. Any thoughts or suggestions? Thanks for sharing and any ideas greatly appreciated!

    1. I don’t think it would be that hard for the team to reverse engineer some of the RED options – even though they probably couldn’t call them the same thing.

      I’ll admit since I’m mainly a longform TV guy I deal with VFX workflow issues infrequently but with that said linear to log or vice versa is totally possible with RCM. But it does seem that that work for a variety of reasons is being handled in an ACES workflow these days.

      1. Heres to hoping about RedLogFilm:).

        I’m still somewhat new to bringing in VFX from vendors, but I’m surprised how few lowmid-range VFX vendors have adapted ACES, let alone other levels of proper color management. Gonna play with lin to log w RCM and see how that works out instead of LUTs. Thanks, Robbie!

    2. I think if anything RCM would be a huge advantage in those sorts of applications.

      There’s one other wrench in the works with R3D’s the redcolor settings fold in aesthetic color matrix transforms… IOW a look. Once that look is baked in, you can’t really reverse it out, and get a technically true version of the image. In any case if you’re getting a lot of baked in red, RCM isn’t going to give you a whole lot of help.

    3. Jason, one potential for a solution (more like a workaround) for baked-in ProRes RedLogFilm is to have them shoot a chart, preferably like one of the DSC CamAlign or Chroma DuMondes, and then you can reverse-engineer a curve and an initial Primary grade to normalize the signal. As I’ve often told people who deal only with digital, not enough DPs shot charts in the film days, so the log signal you see today is pretty much what we saw with film negative. Coming up with a reasonable starting point is something you can create as a PowerGrade. (Or as a pseudo-LUT, for that matter.)

  3. Wow, thank you so much for taking such care in sorting out how Resolve Color Management is dealing with both ProRes Log files versus Raw files and how the various options affect each one! It’s very, very helpful. After seeing how it works though, I’m truly scratching my head trying to figure out why in the hell anyone would ever use RCM for REC709 deliverables , especially on projects that include many different camera and color space sources. Oddly, this seems to be the use case RCM appears to be designed for in the first place. Also, I’m having trouble understanding why even with ProRes log files from Blackmagic’s own cameras (which I work with frequently) working in RCM REC709 timeline and output yields the worst kind of crushed, oversaturated video in the timeline. I’m trying to understand why that look is being promoted as “a good starting point for grading” rather than simply working with a professional set of LUTs or a tool like Film Convert, which with a couple clicks, gets me a starting point for grading in REC709 that looks infinitely better than what RCM starts me with. I know LUTs can clip, but I think most of us know by now how to grade before and after the LUT to easily avoid the issue. Also, when faced with timelines containing shots from different cameras, when I use Film Convert and self manage my color using a calibrated REC709 monitor they all start out looking good and matching one another. With RCM set to REC709 timeline and output, the same shots all begin with looking like awful video and they don’t even match. Have I missed something here? Are you really using RCM as a starting point for grading timelines containing a mix of camera sources when working on REC709 deliverables?

    1. James – I need a little more info. If you’re using RCM but Input, Timeline, Output are all 709 then there should be no difference between your ProRes Log clips in a managed/unmanaged project.

      Are you assigning the clips an input color space? If so what option?

      Also what version of r12?

      Yes I’ve used RCM on a few projects in the past few weeks – mainly alexa (which I work with mainly). Yes, sometimes depending on original shot exposure you can see some weirdness just like with a LUT but do the computational transforms all the data is there to do what you need to do with it with the rest of the Resolve toolset

      So in my expample Log C on Input, 709 on timeline/output. It’s been fine. Other sources if I know what they are I assign input as needed.

      Again LUT workflow, plugins etc are perfectly acceptable ways of working

      1. Hi Robbie,
        Just realized that you replied to my post! Thanks so much! I was working the same as you, but starting from BMCC log clips so it was BMCC log set on Input, 709 on timeline/output. My issue is that working this way the clips look absolutely terrible as starting point for grading. I’ve never liked Blackmagic’s log to REC709 LUT and although I realize that RCM is not using LUTs, the way it transforms the color, contrast and saturation looks pretty similar. I gotta say, it makes the BMCC log clips look freaking awful – like they were shot on a Sony handicam in factory default torch mode. I understand RCM is non-destructive and I can pull the clipped, oversaturated parts of the image all back down to look better, but I don’t see how that saves me any time or headache versus going without RCM. Why would Blackmagic program in such an awful looking transform as a starting point?

        In any case, your advice to use RCM with Input, Timeline, Output as all 709 so there should be no difference between the ProRes Log clips in a managed/unmanaged project is what I’ll do. Seems then I’ll get to keep my old workflow in the timeline, but still get the advantage of RCM for changing output color space when needed.

        Many many thanks for all the help!

  4. It’s interesting to me that the manual only spends about 4 pages covering Resolve Color Management, plus another 4 pages on ACES. I’d like to hear the pros and cons of each and how they work in the real world and where this will save time and money. So far, my impression is that a lot of the advantages are theoretical more than practical, and I’m suspicious of what the camera manufacturers believe will work for their specific color science vs. what happens with real footage. For example, I’ve seen two identical Red cameras from the same scene come up quite a bit differently, even when using identical corrections, because the cameras themselves are not the same.

  5. I’m a bit confounded. If I’m working on multi-camera project with some raw and some non-raw footage, how do I set up the input, working color space and timeline color space? For example, I have an edit ready for grading that has r3d files and mxf files from an FS7, for web delivery. My inclination is to have output and timeline color spaces set to sRGB and s-log3 cine for my input, but am I going down the wrong road? What if you had a project with ari raw and red raw, how would you approach that given what you demonstrated in the video?

  6. So as of resolve 12.5.3 this behavior occurs

    As noted by Alex West here:
    https://forum.blackmagicdesign.com/viewtopic.php?f=21&t=54335&p=313332#p313332

    When choosing Resolve Color Management, the camera raw is bypassed by the input settings of the color management tab, except if you choose “bypass” for the input. In that case, the camera raw settings seems to be taken as an input value. … The fact that the camera settings are bypassed should maybe implied that this tab is greyed in the project settings and in the color page.

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