4 Replies Latest reply on Jun 3, 2015 10:36 AM by trshaner

    DNG Profiles and Colorchecker

    JMDlugosz Level 1

      I used X-Rite's software to create a DNG profile based on a photo containing the Colorchecker calibration target. When applying the profile to the same image, using the eyedropper tool on any of the neutral patches of the target will change the temperature and tint from "as shot" to something else. In fact, the patches can find different corrections!

      I would have thought that the neutral patches would come out exactly neutral.  (Note that I don't mean the warming/cooling off-white. I mean the true neutral ones.)

        • 1. Re: DNG Profiles and Colorchecker
          thedigitaldog MVP & Adobe Community Professional

          The DNG profiles are white balance agnostic to so speak. In other words, just because you have a custom DNG camera profile, you must still deal with white balance. That's by design. As Shot is just Lightroom reading the camera's metadata and it is only a suggestion for WB. Once you apply a custom WB, it disappears with the value of the custom WB you just produced. So, all is fine on your end.

          John Dlugosz wrote:

          I would have thought that the neutral patches would come out exactly neutral.  (Note that I don't mean the warming/cooling off-white. I mean the true neutral ones.)

          • 2. Re: DNG Profiles and Colorchecker
            JMDlugosz Level 1

            So just what does the DNG profile do? How does it work?

            • 3. Re: DNG Profiles and Colorchecker
              thedigitaldog MVP & Adobe Community Professional

              John Dlugosz wrote:

               

              So just what does the DNG profile do? How does it work?

              This may help:

               

               

              In this 30 minute video, we’ll look into the creation and use of DNG camera profiles in three raw converters. The video covers:

               

              What are DNG camera profiles, how do they differ from ICC camera profiles.

              Misconceptions about DNG camera profiles.

              Just when, and why do you need to build custom DNG camera profiles?

              How to build custom DNG camera profiles using the X-rite Passport software.

              The role of various illuminants on camera sensors and DNG camera profiles.

              Dual Illuminant DNG camera profiles.

              Examples of usage of DNG camera profiles in Lightroom, ACR, and Iridient Developer.

               

              Low Rez (YouTube):

              http://youtu.be/_fikTm8XIt4

               

              High Rez (download):

              http://www.digitaldog.net/files/DNG%20Camera%20profile%20video.mov

              • 4. Re: DNG Profiles and Colorchecker
                trshaner Adobe Community Professional & MVP

                JMDlugosz wrote:

                 

                I used X-Rite's software to create a DNG profile based on a photo containing the Colorchecker calibration target. When applying the profile to the same image, using the eyedropper tool on any of the neutral patches of the target will change the temperature and tint from "as shot" to something else. In fact, the patches can find different corrections!

                I would have thought that the neutral patches would come out exactly neutral.  (Note that I don't mean the warming/cooling off-white. I mean the true neutral ones.)

                In addition to Andrew Rodney's excellent video here are some of my observations using the ColorChecker Passport.

                 

                There are a number of things that affect the White Balance (WB) readings in LR:

                 

                1) Actual Scene Lighting Color Temperature

                2) In-Camera Color Temperature Setting (As Shot)

                3) DNG Profile White Balance Differences

                4) ColorChecker Patch Uniformity

                 

                1&2) It's safe to say that the in-camera Color Temperature setting (Daylight, Auto WB, etc.) is an approximation, which will be different than the actual Scene Lighting Color Temperature.

                 

                3) With My Canon 5D MKII the Adobe provided Camera Profiles (Adobe Standard & Camera) require different WB settings than my ColorChecker Passport (CCPP) created profiles. It's not a huge, but it is different. You should be aware of it when changing images from the Adobe camera profiles to your CCPP camera profiles. For my Canon 5D MKII with normal Daylight (5200):

                Adobe Standard 5200 10

                CCPP                5275 16

                 

                4) The CCPP chart patches use paint that is manufactured and applied to produce good uniformity, but there are manufacturing tolerances and color shift from "aging." In addition the 100% White patch is NOT a true neutral patch and should not be used for setting WB in LR. Use the 80% patch next to it or the large White Balance chart on the back of the CCPP. For best results make sure the CCPP chart fills at least 1/4 of the image frame and set the WB picker Scale to maximum. This reduces the affect of noise in the image and samples a larger area of the patch.

                http://www.rmimaging.com/information/ColorChecker_Passport_Technical_Report.pdf

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