13 Replies Latest reply on Feb 18, 2009 10:28 AM by hening

    Exposure correction in DNG not reflected in the DNG-PE

    hening Level 1
      Hi!

      I am trying to make color profiles for 2 cameras I have sold (Fuji E 900 and S 9600). Before I sold them, I took a shot of the ColorChecker for a profile with each of them. Now it turns out that both shots are overexposed. Lowering Exposure by 0,66 EV in ACR brings the reading of the 4/4 field to 100 (ProPhoto space). But when I save the DNG from ACR with this correction, the change is not reflected in the image when opened in the Profile Editor. It does not help to convert anew from the RAF. This is strange. Can I work around it?

      Kind regards - Hening Bettermann.
        • 1. Re: Exposure correction in DNG not reflected in the DNG-PE
          Ramón G Castañeda Level 4
          Henning,

          Using a ColorChecker shot from a camera you no longer have isn't going to do you much good in any event, let alone an overexposed image. :/
          • 2. Re: Exposure correction in DNG not reflected in the DNG-PE
            hening Level 1
            Hi Ramón,

            yes it would do me good if it was correctly exposed, and this is exactly what my question was about: How come that an exposure correction of the DNG in ACR does not show up in the image if opened in the DNG-PE? And is there a workaround?

            Try again... ;-)
            • 3. Re: Exposure correction in DNG not reflected in the DNG-PE
              sandy_mc Level 3
              I would think that DNG-PE is deliberately written to ignore anything other than the raw sensor data; at the end of the day, it's task is to calibrate vs the camera, not any post exposure adjustments.

              I'm not aware of anyway to get it to take anything post exposure into account. But I'd be pretty sure that DNG-PE has automatic exposure compensation built in; it can easily pick that up from the grey-scale patches, so I'd just use what you have.

              Sandy
              • 4. Re: Exposure correction in DNG not reflected in the DNG-PE
                hening Level 1
                Thank you for your answer, Sandy. - The problem is, that in order to make my own profile, I have to visually match the colors to the physical CC chart. The overexposed image looks of course under-saturated, so there is basically no match to begin with.

                Kind regards - Hening.
                • 5. Re: Exposure correction in DNG not reflected in the DNG-PE
                  sandy_mc Level 3
                  Hmmm, so you're not using GM 24 patch chart, so you can't use the PE automated capability?

                  In that case, I don't think PE can help you (much), unless I'm missing a trick here.

                  The only thought I have is build the profile manually - get the measurement from PE, then compute values for the tables in the profile, and assemble it manually. In theory possible, but that's going to be SERIOUSLY painful and take forever. To say nothing of needing to know the spec inside and out.
                  • 6. Re: Exposure correction in DNG not reflected in the DNG-PE
                    hening Level 1
                    Hi again Sandy

                    Yes I use the Gretag MacBeth 24 patch ColorChecker chart, and PE builds the profile automatically, in the first place. But then, I want to fine tune it. This means I set up the physical chart near the monitor, but at an angle to it, and illuminate it with the same 2 Solux® lamps that were used to shoot it. Then I tweak the monitor image until I'm satisfied. Since this implies a visual comparison, an overexposed image is almost worthless.

                    I may have to settle with the automatically created profile, but from my experience with my recent Canon 5D2, my own fine-tuning is more precise.

                    Kind regards - Hening.
                    • 7. Re: Exposure correction in DNG not reflected in the DNG-PE
                      Ramón G Castañeda Level 4
                      Henning,

                      Even if your shots were correctly exposed, it seems to me you'd be building a profile for cameras you no longer own. The whole idea of calibrating a camera is to account for variations in unit to unit but you know all that already.
                      • 8. Re: Exposure correction in DNG not reflected in the DNG-PE
                        MadManChan2000 Adobe Employee
                        Please see the "Apply Camera Raw Adjustments" item in the Options menu.
                        • 9. Re: Exposure correction in DNG not reflected in the DNG-PE
                          Level 1
                          > Even if your shots were correctly exposed, it seems to me you'd be building a profile for cameras you no longer own. The whole idea of calibrating a camera is to account for variations in unit to unit but you know all that already.

                          Three possible reasons I could see doing it are:

                          1) As a favor for whomever he sold the camera to.

                          2) As reference material to get a better understanding of the differences
                          unit-to-unit (or camera-to-camera)

                          3) He has a catalog if existing images from the camera that may need (re)processing.

                          My case would be #3. I've got a catalog of images from my Nikon D100 days that
                          I'd like to take another crack at. If I could find my ColorCheck shots from that
                          camera, I could regen some profiles (and possibly tweak) to see if I can do
                          better with some of the shots with all of the new Adobe toys.

                          -X
                          • 10. Re: Exposure correction in DNG not reflected in the DNG-PE
                            hening Level 1
                            >Please see the "Apply Camera Raw Adjustments" item in the Options menu.
                            Ooops! That simple! THANK YOU Eric!
                            @ xbytor: yes, #3 exactly
                            @ Ramón:
                            IMHO, the mission of the PE goes beyond that. In a post on Luminous Landscape, Eric has "admitted" (well, in my lexikon that would be admitting), that Adobes ready-made profiles are a compromise between accurate and pleasing. For purists like me, the PE offers the option of building my own profile as accurate as I can do it.

                            I'm also under the impression that the profiles allow me to compensate for weaknesses in my monitor/monitor profile. I have of course hardware-calibrated my monitor. But strange enough, across all the 4 cameras for which I have made profiles, if memory serves me, the only major *hue* adjustment I had to make was adding red to patch 2/2. The rest were lightness and saturation adjustments for the most.

                            Thanks again Eric, you saved me!
                            • 11. Re: Exposure correction in DNG not reflected in the DNG-PE
                              hening Level 1
                              I don't know why the Forum software has applied 2 different fonts to my post and swallowed the > in the beginning. It wasn't me ;-)
                              • 12. Re: Exposure correction in DNG not reflected in the DNG-PE
                                Ramón G Castañeda Level 4
                                Henning,

                                Yes it was you. :)

                                The ">", as you refer to it, is the forum formatting code for texquote formatting when you begin a line with it and follow it by a space.

                                >For purists like me, the PE offers the option of building my own profile as accurate as I can do it.

                                Ein Widerspruch in sich selbst. :/ How can a "purist" use a shot from a different camera to build or modify a profile for his own camera? It boggles the mind.
                                • 13. Re: Exposure correction in DNG not reflected in the DNG-PE
                                  hening Level 1
                                  Hi Ramón,

                                  you don't understand what xbytor wrote in his #3: While I had the cameras (2 Fujis), I took shots with them. That was in the bad old days before the DNG-PE. Before I sold the cameras, I took shots of the CC for profling. Now I want to (re)process these older images and need profiles for *them*, not for my current camera. :-) - What *I* do not understand: How could I make overexposed shots of the ColorChecker? Looks like I made triplets and ditched the wrong ones... but *2*/3 f stops?? Yeah, the world is full of mysteries - like innocent quotes that suddenly trigger unforeseen software commands... :-)

                                  Most important: Eric cleared it all up by referring me to a meny command.

                                  Kind regards - Hening.