11 Replies Latest reply on Sep 18, 2015 6:04 AM by b2martin_a

    Tone Curve in Profile Help

    dwbell

      Hey all,

       

      Hoping the more talented tech gurus can help me out a bit here?

      I have custom camera profiles for each of my cameras, so that my colour is consistent across bodies.  They're all dual illuminant, some made in the old DNG profile editor, more recent ones in the Lightroom plug in from Xrite (Passport).

      The colour is excellent, but I always find the tone to be too contrasty for my preference.  When I look at the values on the step chart (greyscale patches) part of the McBeth checker they are not uniform / linear but rather already hold a contrast adding tone curve.  What I do in Lightroom is to take the TAT tool in the curves panel and move these points per patch until they are almost "linear" again.  In effect I apply a custom inverse S or reverse S to the image.  I then save this curve per camera and invoke it on import setting along with the colour profile.  I LOVE, LOVE the files I now get with this calibration, skin tones especially.

       

      BUT

       

      I now have my curve area of Lightroom being used essentially for calibration purposes, which robs me of it's use for creative purposes.  Thus, I'd like to do this tonal adjustment at the profile stage, in the .dcp file to free me up to use the curve panel to suit my artistic vision.

       

      SO

       

      The question is how do I visually target the tone curve in DNG Editor (or passport) to match those which I have created in the curve panel now?  I can eyeball it so they look similar, but it's a bit vague.  Either that or a way to visually adjust the tone curve while viewing the grey swatches within the DNG editor?

       

      The result should be the same as my custom camera profile plus my bespoke lightroom tone curve but all done in the .DCP file.

       

      Am I missing something?  Willing to be schooled always!

      Many thanks if you made it this far.

       

      (Note: I have posted this in LuLa too, so apologies to those who may frequent both)

        • 1. Re: Tone Curve in Profile Help
          areohbee Level 6

          Here's a Lightroom tone curve (saved):

          <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="Adobe XMP Core 5.5-c002 1.148022, 2012/07/15-18:06:45    ">

          <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">

            <rdf:Description rdf:about=""

          xmlns:crs="http://ns.adobe.com/camera-raw-settings/1.0/"

             crs:Version="8.1"

             crs:ToneCurveName="Custom">

             <crs:ToneCurve>

          <rdf:Seq>
          <rdf:li>0, 0</rdf:li>
          <rdf:li>99, 92</rdf:li>
          <rdf:li>166, 156</rdf:li>
          <rdf:li>231, 223</rdf:li>
          <rdf:li>255, 255</rdf:li>
          </rdf:Seq>

             </crs:ToneCurve>

            </rdf:Description>

          </rdf:RDF>

          </x:xmpmeta>

           

           

          and here's the same tone curve in a .dcpr file:

          <dngclr:ToneCurve rdf:parseType="Resource">

              <dngclr:Edit0 rdf:parseType="Resource">

                 <dngclr:X>0</dngclr:X>

                 <dngclr:Y>0</dngclr:Y>

              </dngclr:Edit0>

              <dngclr:Edit1 rdf:parseType="Resource">

                 <dngclr:X>99</dngclr:X>

                 <dngclr:Y>92</dngclr:Y>

              </dngclr:Edit1>

              <dngclr:Edit2 rdf:parseType="Resource">

                 <dngclr:X>166</dngclr:X>

                 <dngclr:Y>156</dngclr:Y>

              </dngclr:Edit2>

              <dngclr:Edit3 rdf:parseType="Resource">

                 <dngclr:X>231</dngclr:X>

                 <dngclr:Y>223</dngclr:Y>

              </dngclr:Edit3>

              <dngclr:Edit4 rdf:parseType="Resource">

                 <dngclr:X>255</dngclr:X>

                 <dngclr:Y>255</dngclr:Y>

              </dngclr:Edit4>

          </dngclr:ToneCurve>

           

          If that's not enough to go on, do tell..

          • 2. Re: Tone Curve in Profile Help
            dwbell Level 1

            Thanks Rob.  So there's a one to one relationship between the curves is what I understand you are saying.

            Knowing that, how would I a) go about getting my LR curve, and b) putting it into the .dcpr file?

            • 3. Re: Tone Curve in Profile Help
              areohbee Level 6

              dwbell wrote:

               

              Thanks Rob.

              You bet.

               

              dwbell wrote:

               

              So there's a one to one relationship between the curves is what I understand you are saying.

              Correct.

               

              dwbell wrote:

               

              how would I a) go about getting my LR curve, and b) putting it into the .dcpr file?

              Easiest way is to use a script I wrote (free):

               

              'Transcribe Tone Curve'

               

              which will transcribe the Lr tone curve in xmp format to an equivalent format which you can paste into your dcpr file.

               

              http://www.robcole.com/Rob/ProductsAndServices/MiscLrScripts

               

              To locate directories containing these files:

              * Run script 'Camera Raw - Shared Folders'

              Lr tone curves (in xmp) are in the 'Curves' folder and dcpr files are in a subfolder of 'CameraProfiles'.

               

              Note: you must save the Lr tone curve for it to be in a file in said directory.

               

              Rob

              • 4. Re: Tone Curve in Profile Help
                dwbell Level 1

                Holy sh.. Rob!  How cool is the internet, and respectively you!?

                Come with obscure problem, find answer in form of prewritten (free) script!  Hot damn.

                 

                Might come back to you here once I've stumbled around.  Not too hot on scripts and such.

                 

                Awesome, thanks man.

                • 5. Re: Tone Curve in Profile Help
                  areohbee Level 6

                  Thanks dwbell .

                   

                  Please let me know (preferrably outside the forum) if that script gives you any trouble.

                   

                  Cheers,

                  Rob

                  • 6. Re: Tone Curve in Profile Help
                    ssprengel Adobe Community Professional & MVP

                    Rob, is the script doing anything more than copying the curve numbers from the saved tone curve to the DCPR file, something that could be done with a text editor?

                     

                    DWBell, are you finding that the inverse S-curve is what you want in the DCPR file or just a linear curve, with both numbers in each pair the same?

                    • 7. Re: Tone Curve in Profile Help
                      areohbee Level 6

                      ssprengel wrote:

                       

                      is the script doing anything more

                      nope.

                       

                      ssprengel wrote:

                       

                      could be done with a text editor?

                      yep.

                       

                      Could also be done using XSLT transformation, if you prefer. The script is just a convenience - if you are happy-enough using a text editor (or xslt) to do the job, then you don't need the script..

                       

                      Rob

                      • 8. Re: Tone Curve in Profile Help
                        dwbell Level 1

                        ssprengel - I expect the script to transcribe the tone curve and nothing else.  As I have no code experience to speak of and several camera bodies profiles to cater to, I'm very pleased that there's a tool that does it for me.

                         

                        Yes, it's the inverse S-curve I want transcribed into the DCPR file.  They are similar in shape per camera, but with tone curves similar is not close enough, they need to be exactly the same.

                         

                        Thanks both.

                        • 9. Re: Tone Curve in Profile Help
                          dwbell Level 1

                          In case some one reads this in the future and wants to go the textedit route.  I have done it this way and it works.

                          What I did to make it easy for me (as in the DCPR file the tone curve language doesn't exist as such) is that I created exactly the number of points in the tone curve in DNG profile editor.  This then creates the required entries into the text.  These entries I then just changed the numeric values copied from the LR Curve file.

                           

                          This does exactly what I wanted it too, and importantly a back to back comparison is visually transparent in the actual images.

                           

                          Thanks again to both.  Rob, I contacted you via your site about the scripts as requested.

                          • 10. Re: Tone Curve in Profile Help
                            panta

                            Where i can download MiscLrScripts ?

                             

                            thanks

                            • 11. Re: Tone Curve in Profile Help
                              b2martin_a Level 2

                              I would like to try your technique, but how do you determine the target values for each of the gray squares on the Passport chart?