6 Replies Latest reply on Jan 6, 2009 10:51 AM by (federico_fiorillo)

    DNG Profile Editor and Camera RAW

      Hi all,
      i have some dubts about the use of profiles in ACR.

      i open a DNG image of a ColorChecker24 image shot with my D200.

      i go in Chart panel, select 6500K and Create color table...

      first question: in the Color Tables panel, i see that some colors are not identical. why ? and what i need to do ?

      then i Export the profile and save the Recipe.

      i go in CS3, open the RAW file with ACR and in the Camera Calibration panel, i select the profile that i have saved previously.

      something happen but

      i try to test the colors with the Color Sampler Tool, but they are all "wrongs" (es: D1(241,241,241) is about (238,237,225); D3(190,190,190) is about (207,206,194); D6(37,37,37) is about (29,29,25) and so on).

      where is my error ?

      just before DNG Profiler, i use a javascript action (ACR_Calibrator_CC24.jsx) to balance the colors and the results seems to be very much better.

      thanks in advance,

      federico
        • 1. Re: DNG Profile Editor and Camera RAW
          MadManChan2000 Adobe Employee
          > open a DNG image of a ColorChecker24 image shot with my D200.
          >
          > go in Chart panel, select 6500K and Create color table...
          >
          > first question: in the Color Tables panel, i see that some
          > colors are not identical. why ? and what i need to do ?

          What do you mean that colors are not identical? There are 18 color patches from the ColorChecker. None of them are identical. So you should not expect colors to be identical ...

          > when i Export the profile and save the Recipe.
          >
          > go in CS3, open the RAW file with ACR and in the Camera
          > Calibration panel, i select the profile that i have saved
          > previously.
          >
          > something happen but
          >
          > try to test the colors with the Color Sampler Tool, but
          > they are all "wrongs" (es: D1(241,241,241) is about
          > (238,237,225); D3(190,190,190) is about (207,206,194);
          > D6(37,37,37) is about (29,29,25) and so on).
          >
          > where is my error ?

          The profile built by the DNG Profile Editor does not attempt to correct tonality (i.e., it does not build a custom tone curve based on the gray patches). It is only attempting to correct hue and saturation of the color patches.

          In general, we feel that tonality should be left in the hands of the photographer, not the profile. You are free to set your own default tone curve, however, if you prefer.

          > just before DNG Profiler, i use a javascript action
          > (ACR_Calibrator_CC24.jsx) to balance the colors and the
          > results seems to be very much better.

          Not sure what you mean by "better". Perhaps you can provide some examples or explain further.
          • 2. Re: DNG Profile Editor and Camera RAW
            Level 1
            Thank you mr. Chan,

            i try to explain me better (sorry for my english).

            the script and the procedure that i use you can find here: http://www.rags-int-inc.com/PhotoTechStuff/AcrCalibration/
            or
            http://www.rags-int-inc.com/PhotoTechStuff/ColorCalibration/

            i have read the features of DNG Profiler about ColorChecker24 and i have supposed that i can gain the same results than the script: change the ACR parameters to 'correct' the output of my d200 linked with my lens.

            here there is an example before script: http://www.rags-int-inc.com/PhotoTechStuff/ColorCalibration/NikonE5400_Default.jpg

            and here, after the script:
            http://www.rags-int-inc.com/PhotoTechStuff/ColorCalibration/NikonE5400_Multi.jpg

            perhaps, i think, this is not the goal of DNG Profiler.

            thank you,
            federico
            • 3. Re: DNG Profile Editor and Camera RAW
              MadManChan2000 Adobe Employee
              The Chart Wizard feature of the DNG Profile Editor should accomplish a similar task. However, it does not modify the tone curve so the overall tonality will not match. I think that is what is causing the confusion here.
              • 4. Re: DNG Profile Editor and Camera RAW
                Level 1
                thank you Chan, i think so.

                can you suggest to me a method as 'work around' to obtain similar task ? perhaps manually tuning the tone curve directly in ACR after applied the profile ?

                but, is it a goal of DNG Profiler ?

                thanks,

                federico
                • 5. Re: DNG Profile Editor and Camera RAW
                  MadManChan2000 Adobe Employee
                  Federico, it is __not__ a goal of the DNG Profile Editor to perform tonal matching. This is why the gray squares appear unchanged after you run the Chart Wizard. There are several reasons that we designed it this way. The primary one is that raw data is already linear; thus a perfect grayscale match against the reference numbers is automatic (within a scaling factor, which can be achieved using the Exposure slider in Camera Raw). However, linear rendering usually looks pretty boring (film isn't linear, for instance). Thus, most of the time you'll want to be using a non-linear tone curve anyways, for aesthetic reasons.

                  Yes, manually tuning the tone curve in Camera Raw is the way to go (you can also tune the tone curve in the DNG Profile Editor, using the 2nd tab). Ideally your tone curve should be fine-tuned to how you want your images to look, not for accuracy reasons.
                  • 6. Re: DNG Profile Editor and Camera RAW
                    Level 1
                    thank you very much Eric.