False Color and LUT Workflow

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  • #216887
    gx42
    Participant

      I am wondering the best pipeline for exposure readings on set, when shooting in Log (or raw) and using false. I like to use false color, and specifically El Zone, to read my contrast ratios in the frame and set highlights. However, El zone turns the monitoring LUT off and reads levels off the Log image. This would seemingly throw off contrast ratios later in the grade, once converted to rec709 and contrast is added. Is this a problem? What am I missing here?

      What is a good monitoring workflow when using false color and viewing Luts? Do you use a different false color tool that reads levels with the Lut applied?

      I also completely see the benefits to using a meter as well, for those who prefer working that way. I am trying to adopt a workflow without a meter the moment. Thank you!

    Viewing 11 replies - 1 through 11 (of 11 total)
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    • #216894
      Sam Higgins
      Participant

        Hi There, What equipment are you using? Seems like something is missing in settings potentially.

        Personally I have the monitoring LUT applied to monitor from source/camera (capture set to RAW LOG with no baked in LUT). My monitor then overlays its false colour on to the received LUT applied image from camera on monitor to reflect contrast ratio in post when coloured.

        As false colour is an overlay of the sensor projection its less accurate but the flexibility of raw/log easily compensates for this. With GIO/EL zones it’s a read from the physically received light not sensor reproduction (Far more accurate) so you would need to know how your monitoring LUT is effecting the stop values & adjust from there.

        Consideration needs to be given to the limited stop range of REC709 vs the cameras capability, I’d recommend editing/monitoring in a wider colour gamut if you are loosing information in your ratios.

        Hope that helps?

        #216897
        gx42
        Participant

          Thank you for the reply, and these are great things to consider! The idea of losing information in my ratios is more speculative than anything. I’m trying to determine if I should be reading false color overlayed onto my LUT, or on the log signal.

          I am using a SmallHD monitor (Indie7 at the moment). The camera really changes per project. Sometimes I will be able to use a Venice, F55 etc, which I can send out the Lut to the monitor. I haven’t tested this theory with these yet.

          I found this issue using an A7siii/Fx3 (which are most of the jobs honestly) and these cameras do not send a lut to monitor. I have my viewing lut loaded into the SmallHD. I notice when I active false color, it automatically turns off the LUT. And I searched and there is no setting to keep the LUT on with EL ZONE. If I switch to Arri false color (on the smallHD) there is an option to leave the LUT on when viewing false color.

          In theory, should false color be viewed with the Lut on or off?

          Hope this helps give some context!

          #216898
          gx42
          Participant

            I am also open to hearing about and learning from other workflows if you have found a system that works for you!

            #216906
            Roger Deakins
            Keymaster

              I am at a loss as to why a meter is not advantageous. It frees you from the monitor and all the complexities of false color, the LUT, etc.. One reading of the light and off you go. When you have practiced with a meter long enough you will find you don’t even need it. Your eye will tell you everything. That gives you real freedom.

              #216908
              gx42
              Participant

                Ah yes, I do hope to reach that point one day. It makes total sense, and always appreciate your insight and responses Roger!

                I should have been more clear in my first question about subject matter, my apologies. I do run and gun documentary shoots a lot. None or minimal lighting for broll scenes. Directors love to call for ‘verite.’

                So I’ve found false color to be a really fast check in these scenarios, when the practicality of a light meter isn’t there. I don’t use it to light from, only to check my face levels and highlights really when working fast.

                I’m just trying to make sure the lut/color pipeline isn’t tricking me

                #216916
                Roger Deakins
                Keymaster

                  Right. A light meter or a monitor take away a lot of the stress but your eye is what sees.

                  #216917
                  gx42
                  Participant

                    A simple, but important reminder. Especially in the screen generation. Thank you!

                    #216924
                    Matt Stahley
                    Participant

                      I  expose by eye but pull up the waveform to just see where everything is sitting. Im colorblind so fall color is pointless to me. to many hues look similar. zebras would be even faster and no need to switch to a false color lut especially if all your doing is checking skin and highlights. Most cameras allow you to set two sets for whatever IRE you need.

                      #216944
                      LucaM
                      Participant

                        I expose by eye but pull up the waveform to just see where everything is sitting. Im colorblind so fall color is pointless to me. to many hues look similar. zebras would be even faster and no need to switch to a false color lut especially if all your doing is checking skin and highlights. Most cameras allow you to set two sets for whatever IRE you need.

                        Zebras are very useful to check if there are clipped highlights or shadows or what is it exactly at a given IRE, but the advantage of false color is checking the contrast ratio of the entire image.  I think both are useful and have their uses. (you could create a black, white and grey false color LUT if you are colorblind, if you think it could help you in your workflow).

                        By the way, Michael Chapman  used how much the eyes hurt to rate the ASA while filming The White Dawn, while (if i am quoting the podcast correctly) Douglas Slocombe used directly his…hand? Plenty of alternatives!

                        #216956
                        Matt Stahley
                        Participant

                          I understand the benefits of false color. The OP at first stated he was using it for ratios but then later on said he was doing run & gun doc shoots and only needed to see where his skin and highlights were sitting that’s why I suggested zebras as they would just appear over his camera lut and he wouldn’t need to be constantly switching Luts.

                          Good idea on the black & white gray  false color but not sure I have the skill or knowledge to create that. Its now something I must research 🙂

                          #216957
                          gx42
                          Participant

                            This is true, I suppose I used the term ratios a little loosely. I think of it that way when doing the interview setups. Since I use the false color on the run and gun scenes a lot, it makes sense for me to also use it for the interviews and seeing where my background levels sit, windows, shadow side etc. It just feels right to use a consistent tool. I’m also starting to be sold on just pulling the meter out with me.

                            Zebras are a good idea for the quick moving setups! Although I’ve liked the idea of seeing how many stops over I am in a certain area, versus just seeing if I am clipping or not (depending on the ire setting). But I could actually see that useful when moving very fast. Thanks for the ideas!

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