7 Replies Latest reply on Aug 17, 2016 11:31 PM by justinw86398615

    How does Lightroom actually handle images with a colour profile?

    justinw86398615 Level 1

      From the relevant help page:

       

      Lightroom simplifies color management by displaying colors using device-independent color spaces. This means that all you need to do before working in Lightroom is to calibrate your monitor. Then, when you’re in Lightroom, choose color settings or color profiles when you’re ready to output your photos. (How to manage color in Lightroom )

       

      So. What actually happens? If an image has, say, a Nikon sRGB profile does LightRoom convert this to Adobe RGB (for the library module) and ProPhoto RGB for the Develp module? This appears to be the implication of the documentation but it doesn't say anything about a conversion.

       

      Basically my question is - does it recognize the provided profile?

        • 1. Re: How does Lightroom actually handle images with a colour profile?
          JimHess Adobe Community Professional & MVP

          justinw86398615 wrote:

           

           

           

          Basically my question is - does it recognize the provided profile?

          In a word, no. The Lightroom develop module works in basically the Prophoto color space. This provides you with the widest color gamut to work with. But you can control the color space in images exported from Lightroom.

          • 2. Re: How does Lightroom actually handle images with a colour profile?
            Per Berntsen Adobe Community Professional

            First of all, if you're working with raw files, they are greyscale files, and don't have a color profile. Any profile you choose in the camera only applies if your'e shooting jpgs.

            But raw files contain color information, which is converted to real colors in the conversion process.

             

            If you're importing rendered files, like tiff, psd, jpg, I'm guessing that LR reads and respects any embedded profile, but will probably convert the previews to Adobe RGB/Prophoto as required. All the work you do in Lightroom is done with previews, what you're seeing on screen is not the original image.

             

            In general, Lightroom will display your images correctly, as long as you have a calibrated monitor, and the monitor profile is sound.

            1 person found this helpful
            • 3. Re: How does Lightroom actually handle images with a colour profile?
              justinw86398615 Level 1

              Thanks Per.

               

              So as far as NEFS go you seem to be saying that in effect there is no colour profile. Lightroom just reads the raw data and assigns the ProPhotoRGB profile? There is no conversion. Just numeric pixel values?

               

              As fas as jpegs go you are correct. Lightroom recognises and converts the image using the supplied colour profile. I tested this by importing an image which has a very unusual colour profile applied. If there is no conversion you see strange colours. I didn't see strange colours so Lightroom definitely respected the profile - both for its preview and for its conversion to ProPhotoRGB. In case it helps anyone else this is the image I used for the test: (the car): http://petapixel.com/2012/06/25/is-your-browser-color-managed/

              • 4. Re: How does Lightroom actually handle images with a colour profile?
                thedigitaldog MVP & Adobe Community Professional

                justinw86398615 wrote:

                 

                Basically my question is - does it recognize the provided profile?

                Yes!

                Also see: http://digitaldog.net/files/18Color%20Management%20in%20Lightroom.pdf

                • 5. Re: How does Lightroom actually handle images with a colour profile?
                  DdeGannes Adobe Community Professional

                  Quote

                  "If you're importing rendered files, like tiff, psd, jpg, I'm guessing that LR reads and respects any embedded profile, but will probably convert the previews to Adobe RGB/Prophoto as required. All the work you do in Lightroom is done with previews, what you're seeing on screen is not the original image."

                  end Quote

                  When you import files into Lightroom Previews are built which are in the Adobe RGB profile, these previews are used by the Library and modules other than the Develop Module. When working in the Develop Module the original file data is used to display the image file in a ProPhoto RGB colour working space. Each time you make a change in the develop module the original file is used to re-render the display. It therefor stands to reason that if the original file is a raw file you will have the full image data to work with, while if you are working with a jpeg or tiff with a sRGB or AdobeRGB colour profile you will be working with limited data for the ProPhoto RGB colour working space.

                  This is why it is necessary that you have to "calibrate your monitor" to accurately and consitantly display your images in the various modules.

                  To wit, if the original file has a sRGB profile then colour data is limited by that profile and cannot be recovered. That is why it is important to work with the raw file in Lightroom.

                  Always remember Lightroom never alters your original imported files. If you import a jpeg file with a sRGB colour profile it will always remain exactly the same.

                   

                   

                   

                  1 person found this helpful
                  • 6. Re: How does Lightroom actually handle images with a colour profile?
                    Conrad C Adobe Community Professional & MVP

                    justinw86398615 wrote:

                     

                    Thanks Per.

                     

                    So as far as NEFS go you seem to be saying that in effect there is no colour profile. Lightroom just reads the raw data and assigns the ProPhotoRGB profile? There is no conversion. Just numeric pixel values?

                    Right, there is no color profile. But something has to be used to interpret the NEF while converting it from a typical raw file (just a bunch of grayscale values) to become a recognizable RGB image. Reading the numeric pixel values isn't enough without some kind of reference, and an ICC profile won't work on a raw file, so what happens is:

                     

                    Lightroom processes the raw numbers through the default Adobe camera profile for your Nikon camera model. A camera profile is not the same as an ICC profile. This Camera Profile determines the initial look and colors of a raw image before any other Develop settings are changed, so if you don't like the default look, you can choose a different camera profile (if available) or create your own. You can change the Camera Profile in the Camera Calibration tab at the bottom of the right side of the Develop module. Adobe camera profiles produce a look that is close to, but not exactly, what you would get viewing the NEF in Nikon software or the raw file's JPEG preview.

                     

                    After that initial conversion based on the camera profile, Lightroom will apply any other default Develop module settings. In Lightroom, the result of that exists in the built-in Lightroom color space (ProPhoto RGB with sRGB-like tone curve) and then, finally, you see the final result through your (hopefully up-to-date) display ICC profile.

                     

                    So, the way your NEFs look in Lightroom before editing is affected by the Adobe camera profile + default Develop settings.

                    • 7. Re: How does Lightroom actually handle images with a colour profile?
                      justinw86398615 Level 1

                      Thanks Per. I would have marked this as the correct answer but I needed a little more detail which came in a follow-up. But thanks. This set me on the right track.