LUT Creation to use on set

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  • #176149
    indiefilmmaker
    Participant

      Hey everybody,

      I’m heading into my directorial debut and was wondering how I could see the “closest to final image” using a LUT.

      I’ve read that Mr. Deakins uses the same LUT on set for pretty much all of his films. Does anyone know how he created it, if I can find it somewhere, or how I would create one to my taste to make the post workflow go faster? I Googled and I saw a couple posts from a few months ago that are now gone so I’m just looking for some more information.

      I do have a look that I want to replicate from Blade Runner 2049,

      Blade Runner 2049

      pretty much this color palette. It has all the same elements too. Night shot, car lights, and rain.

      I’ve worked in all aspects of the production workflow except as the director so I do know how to color grade and light and do all that. Do I generate a ramp in Resolve and just use curves with an 18% grey middle point and adjust the RGB channels accordingly?

      Any helps is greatly appreciated.

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    • #176154
      Roger Deakins
      Keymaster

        The LUT we use was created at E-Film, now Company 3.  It is not hard to do. Just shoot some tests and take them to them DI suite.

        #176159
        dmullenasc
        Participant

          The color palette of “Blade Runner 2049” is not really due to the LUT, that’s lighting and design mostly.  If it were due to the LUT, then all of Roger’s movies shot on the Alexa would have the same color palette!

          I wouldn’t over-emphasize the importance of the LUT in terms of cinematography. It is a relatively minor thing compared to lighting, composition, exposure, lenses, etc.

          Most LUTs exist to transform a log image into a display gamma so that the contrast and saturation can be correctly evaluated. They may have some personal adjustments in terms of gamma in the shadows, midtones, and highlights, and in saturation.

          My method for creating the shooting LUT on the Alexa is to shoot a face and some charts, record them in Log-C (or Arriraw converted later to Log-C), and then take them to a post house to color-correct them and then have the colorist generate a LUT.

          I shoot a face and some charts (grey scales, etc.) separately and color-correct both and toggle back and forth to see how my corrections for the face affect the charts and vice-versa. That way I end up with a LUT that works both for a real face and for a grey scale.

          As a reference on the testing day, I also record a baked-in Rec.709 version (since I’m shooting for broadcast HD) so I can compare my LUT to what ARRI thinks is a basic conversion LUT for Log-C to Rec.709. I guess one could do the same thing in P3 for a theatrical project but you’d have to think about whether dailies will be in Rec.709 and whether your main set monitors are P3.

          Keep in mind that the LUT is mainly just for on-set displays and for dailies creation. The final color-correction might start from scratch from the log image or use the LUT as a starting point.

          I have a DIT on my crew so I can make adjustments on the day (like to match two lenses that don’t quite match in color, or add contrast in flat weather or reduce contrast in harsh light) — these are sent as ASC-CDL files to the dailies colorist to apply to the LUT.  If I didn’t have a DIT, I might be tempted to create three LUTs (basic look, a slightly low-contrast version, and slightly high-contrast version) but you’d have to think about whether you’d just be making life too complicated for your ACs and your dailies colorist.

           

           

          #176174
          Stip
          Participant

            If you create your own LUT make sure, like Roger mentioned and David outlined, to test it in a broad variety of situations; night/day, int/ext, slightly over-/underexposed, on saturated colors ect.

            Because it has to work in all situations, it won’t be too invasive. People fantasize about getting their hands on Roger’s LUT since years, but I’m sure they’d be very disappointed to find out it doesn’t magically turn their footage into Roger’s 🙂

            #176204
            Roger Deakins
            Keymaster

              I would be very surprised if the LUT I use is very different from any other. The only adjustment in it is to the contrast curve and the amount of color saturation. That is standard for any LUT that translates the RAW data.

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