7 Replies Latest reply: Jun 4, 2010 4:21 PM by D Fosse-QDEaQ1 RSS

    Color Settings (Profile) Question

    rollsnut Community Member

      -I am using CS4 on a PC.

      -A friend of mine does high end printing.

      -A couple of months ago he had me set my color settings to ProPhotoRGB. In the haste they were not set back. To sRGB IEC61966-2.1 (sRGB for later reference). Innocently I thought working in ProPhoto (yes I had the choice when opening a file which profile to use) would somehow enhance the photo. Now I know better, but…..

      -I manipulated many photos using the ProPhoto setting, but in some cheap, quick printing to a universal machine most consumers would have processing done with, they looked horrible, to say the least.

      -We determined the problem to be the setting and I have switched it back to sRGB.

       

      Question:

      Can I open the old processed photos and change the Color setting (EDIT-> Assign Profile) and be good to go, or are the ProPhoto colors embedded in the photos and I need to start from scratch with my RAW files and convert to new jpg files and move forward?

       

      I tried opening one of the bad jpg and converting the color setting/profile and even opened a psd I had created of a collage and saved it as a jpg but in Bridge the color still looks bad. (PSD color is fine).

       

      If I have to start over, so be it. It’s only months, not years and I will have learned something. I would however, like to speed up the process an easier way, if possible.

       

      Thanks for any response.

        • 1. Re: Color Settings (Profile) Question
          Curt Y Community Member

          Yes you should be able to just change as you stated.  ProPhotoRGB is a wider gaumet color range so some color shifting may be evident.  This gets into a very complex subject, or which I am not an expert.

          • 2. Re: Color Settings (Profile) Question
            D Fosse-QDEaQ1 Community Member

            In short: use convert, not assign.

             

            Convert changes the RGB numbers to keep the appearance unchanged.

             

            Assign keeps the numbers, but the interpretation of the numbers is different, so the colors change.

             

            Expect some color channel clipping when you go from ProPhoto to sRGB. Yes, in a sense ProPhoto is better, because it's bigger and contains  more colors. But you have to know the implications of that to take advantage of it. It mainly gives you a lot more headroom in the editing stage. The trick is to squeeze it back into sRGB or Adobe RGB for final output.

            • 3. Re: Color Settings (Profile) Question
              rollsnut Community Member

              Ok, I think I have the solution and I'll post it here in case anyone else has the same

              problem in the future.

               

              My buddy called ( he feel really bad for messing me up in the first place) and he offered this solution which works and makes sense....

              Open the photo

                   EDIT

                   ASSIGN PROFILE - to make sure it has the ProPhoto profile.

                   CANCEL

               

              IMAGE

                   MODE

                   Select LAB COLOR

               

              IMAGE

                   MODE

                   Select RGB

               

              To verify change:

              EDIT

              ASSIGN PROFILE - find that sRGB radio button is selected.

               

              Now just to create a macro(Action) to mass process them all!

               

              Thanks to all who read this and offered solutions.

              • 4. Re: Color Settings (Profile) Question
                D Fosse-QDEaQ1 Community Member

                Just convert to (not assign) sRGB and be done with it.

                 

                There's no reason to go via Lab.

                • 5. Re: Color Settings (Profile) Question
                  rollsnut Community Member

                  I believe you and for some reason it worked on some of the files but

                  not all of them - I don't know why. The process I did was full proof on

                  ALL the files.

                   

                  You are probably 100% correct in most cases and I did use your method until it failed on several files and I had to find a way to conver them.

                   

                  Thanks for your input. I'mnot slighting it in the least.

                  • 6. Re: Color Settings (Profile) Question
                    Noel Carboni Community Member
                    function(){return A.apply(null,[this].concat($A(arguments)))}

                    D Fosse wrote:


                    In short: use convert, not assign.

                     

                    Convert changes the RGB numbers to keep the appearance unchanged.

                     

                    Assign keeps the numbers, but the interpretation of the numbers is different, so the colors change.

                     

                    Expect some color channel clipping when you go from ProPhoto to sRGB.


                    I have developed an action that affects this exact conversion (ProPhoto RGB to sRGB) without clipping (but with color shifts instead to compensate for out-of-gamut colors).  In a sense, less data is lost through the use of this action.

                     

                    In fact, it's a good idea, if such clipping bothers you, to always convert raw files into ProPhoto RGB then use a "less lossy" technique like this action to convert to sRGB, because the channel clipping mentioned by D Fosse above happens during conversion as well.

                     

                    If you'd like to try the action:

                     

                    Run it on a flat ProPhoto RGB image and you'll get a flat sRGB image.  Simply put, it shifts some colors to fit the smaller color space, while attempting overall to maintain the original color.  It works around the clipping of color channel data one sees from Absolute Colorimetric conversions directly to sRGB..

                     

                    http://noel.ProDigitalSoftware.com/temp/ColorSpaceAction.zip

                     

                    Right click the above, unzip, and save the .atn to your disk.

                     

                    Load into Photoshop via the Actiona Palette menu, Load Actions entry.

                     

                    Open a raw image into ProPhoto RGB (I recommend 16 bit), then run this action at some point after to convert the image to sRGB.  I have assigned it to a function key.

                     

                    Enjoy!

                     

                    -Noel

                    • 7. Re: Color Settings (Profile) Question
                      D Fosse-QDEaQ1 Community Member

                      rollsnut wrote:

                       

                      it worked on some of the files but not all of them

                      The thing is, if you start assigning profiles you get into deep waters pretty quickly. The file itself is unchanged; the RGB values the same - but the colors change completely because the numbers suddenly have a different meaning.

                       

                      So that's when you need to retrace your steps to get back to where you were. Then you need to reassign the original profile.

                       

                      But apart from that, convert is what you want.

                       

                      As for Noels action I've tried it and it works. The term for what it does is gamut mapping - or rather remapping (personally I prefer to do that manually, but that's a different story).

                       

                      Here's an example of a strong yellow-green that causes blue channel clipping in sRGB:

                      blue clipping.png