19 Replies Latest reply on Jan 5, 2009 10:01 AM by (Jeff_Schewe)

    Is my ColorChecker shot usable?

    Level 1
      I don't own a Colorchecker myself so I asked a member of the dpreview forums to take some shots of his chart with his EOS 30D.

      When I got the shots I noticed, after a while, that the tungsten shot wasn't really evenly lit.

      Here's a crop of the chart:
      http://davidnaylor.org/temp/colorchecker.jpg

      As you can see, the black frame is quite a bit darker in the top left corner than in the bottom right corner.

      So, is this shot usable at all for creating a ColorChecker-based profile with DNG PE?

      I noticed the shot in the tutorial isn't very evenly lit either ( http://wwwimages.adobe.com/labs.adobe.com/cdn/wiki/images/f/fc/Pe_cc24_circles.jpg ) so I really have no idea now. :/

      Would be very greatful for any pointers. Thanks!
        • 1. Re: Is my ColorChecker shot usable?
          Level 1
          >I don't own a Colorchecker myself so I asked a member of the dpreview forums to take some shots of his chart with his EOS 30D.

          And you are trying to accomplish what? Practice making profiles or hoping for some sort of divine help? Using a CC shot from a DIFFERENT camera than yours is a wast of time. Add that to the fact that the shot is poorly lit and exposed and you're not going to get anywhere good...
          • 2. Re: Is my ColorChecker shot usable?
            Ramón G Castañeda Level 4
            David,

            Jeff has phrased it in the most polite way. Here's another way to look at it: If you were to fall ill suddenly, would you send a friend of yours who lives closer to the lab to have his blood drawn instead of yours? Would you then take medication prescribed by the physician based on those results?

            Doesn't sound too smart, does it?
            • 3. Re: Is my ColorChecker shot usable?
              Level 1
              Well, I believe the differences from camera to camera are negligable. Since buying a ColorChecker for a crazy amount of cash is not an option, this is the next best thing.

              So, if you could just try to ignore the fact that I am using a different camera and answer the question?

              "Jeff has phrased it in the most polite way."

              I wouldn't agree.
              • 4. Re: Is my ColorChecker shot usable?
                Level 1
                >So, if you could just try to ignore the fact that I am using a different camera and answer the question?

                The original shot is crap...under exposed and unevenly lit. It's a waste of time to try to use it. That clear enough?
                • 5. Re: Is my ColorChecker shot usable?
                  Ramón G Castañeda Level 4
                  >Since buying a ColorChecker for a crazy amount of cash is not an option, this is the next best thing.

                  That is the dumbest thing I've read here in a long time. There's no way to put it more mildly.

                  >I believe the differences from camera to camera are negligable [sic]

                  If that were the case, you would have no reason to calibrate the camera.
                  • 6. Re: Is my ColorChecker shot usable?
                    Level 1
                    Wow, I'm really thrown by how unhelpful and impolite people are here.

                    Thanks Jeff for the answer, I guess.

                    Edit: As for the notion that camera output varies greatly from copy to copy, I am having serious difficulties of finding any such evidence on the web.
                    • 7. Re: Is my ColorChecker shot usable?
                      JimHess-8IPblY Level 3
                      David,

                      You are not trying to profile Photoshop or ACR. You are trying to create a profile for your camera. To do that, you need to use a photo taken with that camera. Otherwise, how are you going to know how that camera is going to render the color chart?

                      It costs money to purchase a color checker. But if you are concerned enough about proper color and exposure, etc., it seems to me that the cost would be justified. Otherwise, just use the profiles Adobe has created. You can use one of those as a starting point to create your own custom profile if necessary.

                      Raw photography and Photoshop/ACR is an individual camera issue. If you want to do the whole process correctly, you need to do everything with the camera you are trying to profile.
                      • 8. Re: Is my ColorChecker shot usable?
                        Level 1
                        The reason for my profiling is this:

                        I have always used Canon Raw Image Task (aka Zoombrowser or RIT) for my RAWs since it produces the same colours as the camera JPEGs.

                        For some reason Canon decided to produce different outputs from Digital Photo Professional (DPP), which seems to me as the weirdest decision of the decade.

                        Adobe's DNG profiles mimic the picture styles produced by Canon Digital Photo Professional (DPP), since most Canon people have used that software rather than RIT.

                        Since I want the RIT output look, the profiles are no good to me.

                        I have used the Picture style "Faithful" which is meant to be colourimetrically correct (see http://www.usa.canon.com/content/picturestyle/shooting/faithful.html ).

                        Since a ColorChecker-based profile also would be colourimetrically correct I'm thinking it would be the second best thing for me to actually having a profile made by Adobe.

                        And since I don't own a chart myself, and I have yet to see any evidence of huge variations in output from camera to camera, I'll settle for a shot taken with another camera of the same model. (If you know of such evidence, do post a link.)

                        Now it turns out this shot is no good. But I still believe my method could work, if I just get good enough shots of the chart taken with a 30D.
                        • 9. Re: Is my ColorChecker shot usable?
                          JimHess-8IPblY Level 3
                          All I can say is, you just don't get it. But that's okay, go for it. You just might discover a whole new process that will revolutionize raw photography.
                          • 10. Re: Is my ColorChecker shot usable?
                            Level 1
                            That's right, I don't get it. Because I haven't ever seen a side-by-side comparison showing two identical cameras producing different outputs.

                            Have you?

                            For me to buy a ColorChecker for X amount of money I need to know that there is a considerable risk of my 30D sensor behaving differently to this other guys 30D sensor. Is that so crazy?
                            • 12. Re: Is my ColorChecker shot usable?
                              MethodPhoto Level 1
                              If you are so worried about the issue, then surely $45 is a small price to pay??! Since there are enough people around who do think it is worth having them, and some who are sadly not around, maybe it is a worthwhile investment.

                              http://is.gd/eAkX
                              • 13. Re: Is my ColorChecker shot usable?
                                MadManChan2000 Adobe Employee
                                > That's right, I don't get it. Because I haven't ever seen
                                > a side-by-side comparison showing two identical cameras
                                > producing different outputs.

                                > Have you?

                                Yes, and in some cases the differences can be visually
                                significant. I am not saying this is common, but it does
                                happen.

                                Eric
                                • 14. Re: Is my ColorChecker shot usable?
                                  Level 1
                                  Ok. Thanks for the clarifying reply Eric!
                                  • 15. Re: Is my ColorChecker shot usable?
                                    JimHess-8IPblY Level 3
                                    If camera sensor were consistent then, theoretically, there wouldn't even be a need for something like the Profile Editor. We could all rely on the standard profiles created by Adobe or by other software developers. I have played with the Profile Editor a little, but I guess my photography is not that critical as far as color matching is concerned. I find that in most instances the Adobe standard profile works just fine.
                                    • 16. Re: Is my ColorChecker shot usable?
                                      Level 1
                                      Well, I'd say one of the main uses for PE is creating a look that is *to your liking*, not necessarily colorimetrically correct.

                                      My photography is far from colour critical, but I happen to like a certain look, which according to Canon is colorimetrically correct.
                                      • 17. Re: Is my ColorChecker shot usable?
                                        Level 1
                                        >which according to Canon is colorimetrically correct.

                                        :~) Boy, I sure hope you don't believe that...all of Canon's "looks" are a bit far from "colorimetrically accurate". The Adobe Standard profile is, for all of my cameras, the most accurate in terms of rendering known and measured colors accurately. Canon's Faithful isn't very accurate when comparing measured targets.
                                        • 18. Re: Is my ColorChecker shot usable?
                                          Level 1
                                          > Canon's Faithful isn't very accurate when comparing measured targets.

                                          Ok. Are you talking about DPP Faithful or RIT Faitful or both?
                                          • 19. Re: Is my ColorChecker shot usable?
                                            Level 1
                                            >Are you talking about DPP Faithful or RIT Faitful or both?

                                            Nothing from Canon is "colorimetrically accurate", Faithful is just less bad from either app...