Charting Gamma Curves, Revisiting REC-709a, and Premiere Pro 2022 Color Management

June 17, 2022

Team Mixing Light, and members, discuss Log Gamma curves, revisit Rec-709a, Premiere Pro 2022's color management, and declining job offers.


Series

Office Hours – June 9, 2022

Mixing Light Contributors Peder Morgenthaler, Jason Bowdach, Joey D’Anna, and Cullen Kelly join host Patrick Inhofer in leading a Mixing Light Office hours discussion. Today’s discussion included:

  • Deconstructing the electronic journey of images from capture to display
  • Revisiting Rec-709a and the assumptions behind it
  • The history of the various Log-C formats
  • The Log10 curve
  • Color managed color grading when you don’t know the camera or recording profile
  • Premiere Pro 2022 and how it’s making a mess of color-managed workflows
  • Declining a job if it’s too much of a mess

Table of Contents

  • 00:00 – Introduction
  • 00:45 – Contributors discuss what they’ve recently learned that they didn’t know before
  • 01:16 – Peder talks about his new sit-to-stand TBC console for his grading suite
  • 02:06 – Cullen has designed a new suite of tools for balancing images and is looking forward to share it
  • 03:16 – Joey updated his Dehancer plugin for Resolve and is really happy with its color science
  • 04:55 – Patrick is annoyed by the El Gato foot pedal he recently purchased
  • 07:08 – Jason is re-invigorated by approaching color grading from the perspective of human psychology and perception
  • 11:19 – Discussion of the grade for Top Gun: Maverick
  • 12:28 – Why isn’t the classic Log-to-video transform just the inverse of the original gamma transform that’s applied in the camera? Why do we use an S-curve?
  • 18:00 – Cullen uses Fusion to show the ‘color journey’ of an image from capture to display
  • 21:36 – Jason mentions the importance of knowing your capture ‘flavor’ for proper image reproduction of raw images
  • 22:50 – Circling back to the ‘Rec-709a’ fix for Apple displays and how it’s related to the original question
  • 27:27 – What’s with the different log curves (Arri Log-C, S-Log, RedLog3G10, etc)? What’s the history of these solutions?
  • 31:44 – Cullen shows the Log10 curve which is the basis of film negative capture – and is relevant in digital workflows
  • 33:40 – Jason talks about the shift in middle gray on the new ARRI 35 sensor
  • 35:19 – The importance of not making assumptions about the log-encoding method based solely on the camera manufacturer
  • 37:48 – Patrick posits: What if you don’t know the camera or the recording settings?
  • 41:27 – Color grading in flat-file or ‘baked’ workflows and how Premiere Pro 2022 is messing up renders
  • 44:47 – Joey advocates for ACES to be implemented on all NLEs.
  • 46:04 – Why color management on Premiere is not well implemented
  • 49:01 – How even in-house productions can’t keep track of recording settings for color-managed workflows
  • 52:40 – Is there anything wrong with just putting your hands on the rings and balls and color grading to the eye?
  • 54:16 – You CAN say no to a job if there’s no data for a proper color-managed workflow
  • 55:36 – Goodbyes

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Comments

Homepage Forums Charting Gamma Curves, Revisiting REC-709a, and Premiere Pro 2022 Color Management

Viewing 3 reply threads

    • Marc Wielage
      Participant

      We occasionally get in a screwed-up project from an ongoing client where they used 5 different cameras, and nothing is identified, some stuff has LUTs, some stuff is log, some is somewhere inbetween. Do we turn it down? Not if they’ll pay our hourly rate. We warn them in advance, “hey, some of this is way out of whack. We’ll guarantee it’ll be BETTER, but it won’t be perfect if we don’t know what camera it is or how it’s been stomped on by editorial.” Generally the producers we work with are understanding and say, “hey, this is what we were given. Do your best, make it look reasonable, and we’ll work it out.” But turn it down because of the lack of color-management data? No way.

      This is assuming it’s a promo or a trailer or a commercial or something like that. If it’s longform, then we’d have a whole different conversation. We currently have stuff up on Amazon and a few national cable services that were not color managed at all: we just whacked at it until it looked reasonable in a display-referred setup. And in the end, the client was happy and the check cleared.


      • Patrick Inhofer
        Keymaster

        Marc – I’m with you. We ran out of time at the end of this Office Hours and didn’t dig more deeply into Cullen’s suggestion. I see unmanaged projects as an opportunity for specialization. In 5 years, fewer and fewer colorists will want to work on unmanaged projects because they’re harder to execute at most stages of the process.

        This will open the door for other colorists to specialize in these workflows.

        Until the industry comes up with a range of standard metadata automatically embedded in every bit of footage ever recorded on every camera, this problem is never going away – as Jason has discovered, even with internal production departments that can dictate these things!


      • Cullen Kelly
        Participant

        Thanks for your perspective Marc! Definitely wouldn’t want to knock anyone’s hustle, or stipulate what jobs are OK to take. The only ones that aren’t are the ones you don’t actually want! I’ve learned the hard way that saying yes to those is a lose/lose for everyone, and that “no” isn’t a dirty word 😂


    • Jamie Dickinson
      Participant

      Hey, thanks so much for digging into this question so comprehensively! Sorry I couldn’t join you for the discussion. You all really answered the question brilliantly. I’m probably going to need to watch this more than once to really digest it.


    • R Neil Haugen
      Participant

      I can fill in some on the Premiere side … and sad to say, like Pat said, it ain’t pretty. The fact is they COMPLETELY rebuilt all color handling for the Pr2022 build series. It’s what I call “color space agnostic”. While before it was totally Rec.709, allowing for HLG/PQ media via “overrange Rec.709 values” according to their chief color scientist.

      And yea, like before, ALL color math is 32-bit float (even if sometimes the in/out processes are screwing the color depth up). So yea, it COULD be so much more. I’ve pushed Lars Borg et all for going to a P3/D65 working color space. Then with a monitor/viewing and export color space controls to simplify things. Unifying behavior of color tools no matter the media, SDR/HDR, whatever. Ah well, we got … this.

      I’ve asked both electronically and in-person about specifically this new version … is it as it feels, a complete break/rebuilding of the color system? And in all replies, that question is completely passed over without comment or reaction. Without eye contact at NAB. Knowing Adobe-speak as well as I do, that means … um … they won’t say I’m wrong ’cause I ain’t, but they’re not allowed to say I’m right either. Adobe being … yea.

      And they did mention in their official documents at release that it had some new color handling sort of, but … only in talking about the bits & pieces of it that the user sees. And I have the feeling that there may be a discrepancy between what the team would like to talk about, and what Marketing thinks the users need to know … or would be confused by. Marketing & Experience … M&E … Rule.

      Thus making a complete and total mess out of the new changes and capabilities. Few users even now fully understand what’s the proper steps and full capabilities. Which by the way, change with every update. Oh … so … um … wow.

      But that said, Peder is wrong about needing to go into a “debug” menu to “fix” the problems with S-log3.cine … that isn’t a debug panel.

      <span style=”text-decoration: underline;”>Weird to say, but that’s the place where the new color management controls are located!</span> This is for functions similar to the Media Pool controls in Resolve. And the engineers think that going to the Project panel, RIGHT-CLICKING individual media clips to get a context menu up, then select Modify/Interpret Footage, is the most ‘normal’, obvious, and user-expected way to get to clip color management controls.

      At the bottom of that panel is where they put the new media color management tool. Not in a separate panel the user can open from the menu of panels … but buried in a right-click context menu.

      I simply cannot express here my full thoughts on that decision.

      But what’s been more of a mess was that at the initial release, they had only a few formats (Red/Arri) “color managed”, most others including Sony, Canon, and Panny weren’t. And the way the new defaults worked … and y’all will love this … is captured in a comment from Kevin Shaw. Although he wasn’t talking about Premiere at all …

      Kevin Shaw commented in one of his HDR classes that some SDR is log-encoded, but ALL HDR is log-encoded.

      Bingo. You see what’s happening? Premiere’s spanking new CM assumes that any log-media that it doesn’t have a specific hardwired coding for, must be HLG. And will assume and tag that as being HDR/HLG.

      To use that on a Rec.709/Bt-1886 timeline, you need to Modify/Interpret Footage to get to the new CM controls … and set say an Override value to Rec.709.

      They do have a new transform for S-log3.cine finally, and it’s pretty nice … I’ve run a few clips through it that had really bright extended highlights, and what it did to remap that to Rec.709/Bt-1886 in the highlights was sweet. I couldn’t come close to bringing out the level of shading and detail in the brights that their transform did.

      So … overall, wow … I’m rather irritated at this moment … for now the last seven months, over this … slow, painful rollout of new color tools, defaults, behaviors, and everything. That we users pretty much have to drill and test through to find out what the heck is going on.


    • Jim Robinson
      Participant

      The revist to rec709-a discussion it seems that the information available out there is how to use rec709-a but very little on what it actually does to your video.
      When moderating Resolve user groups on Facebook, this subject, because people are buying M1 powered laptops or imacs, with the screen built in – that the subject of “Why does my video look washed out on renders” has to be the number one topic of posts in the last 6 months or so.
      Now explaining the whole colorsync information and what Cullen was speaking of rec709 and BT1886 and Apple using gamma 1.95, is how we have been explaining rec709-a and then we explain how to apply it in Resolve.
      But for me as I try to totally understand things, I am also left with questions about it.
      Is it just a hack to change the gamma?
      Is it something that only Colorsync knows what to do with it, or is it changing the gamma on everything exponentially?
      Meaning if a player is color managed is it add gamma value to it on a PC?
      The lack of actual information from Resolve and in general on the Internet, leads to all kinds of questions. We can just disregard the problem, and assume that a  lot of people will see the correct grade, but there is a lot of iphones out there. Are we making washed out videos for them? If we fix the images in anyway, is it making crunchy high contrast images on androids and PCs?
      Still trying to figure out why most Macs now have gamma 2.2 displays and how colorsync fits into the equation- why would they then process the gamma at 1.95? Bit of a mystery to me.

      • This reply was modified 4 days, 20 hours ago by Jim Robinson.
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