12 Replies Latest reply on Oct 16, 2013 2:45 PM by rob day

    InDesign Transparency issue

    Chez Voz

      When applying a transparency to an objet, the b&w photo in the object below also dims. I've tried putting the object with the transparency applied to it on the pasteboard-not over the photo, but it still happens. I tried a test doc with just the photo and an object  on top-same problem. I tried it on a another existing dock with color photos and it worked fine. Any ideas?

        • 1. Re: InDesign Transparency issue
          Michael Witherell Adobe Community Professional

          What filetype is the image and the background image?

          What color model is the image and the background image and the document itself (Edit > Transparency Blend Space)?

          • 2. Re: InDesign Transparency issue
            Peter Spier Most Valuable Participant (Moderator)

            Grayscale photos are passed to the K plate of the current CMYK working space, and the preview may not match what you see in Photoshop becasue ID doesn't understand grayscale profiles except during export to PDF.

             

            When you introduce transparency, ID redraws the screen to give you a more accurate preview of what the final output will look like, but if you check the numbers in Separations Preview you'll see they have not changed.

            • 3. Re: InDesign Transparency issue
              Chez Voz Level 1

              Wow, quick replays, thank you both.

               

              This is a B&W ad for print.

               

              Peter, I think you are saying that what I'm seeing in ID is a translattion error onscreen only. But I did a test exporting to pdf and the problem is still there.

              The file is a tif (same as my test with a color image).

               

              Michael, I changed the transparency blend space from CMYK to RGB and that changed the onscreen appearance. I exported to pdf, ignoring the warning message about the RGB, and in that case, the transparency is OK (although I don't know if there will be problems sending this to the printer.

               

              I'd hate to have to steer clear of this because it take sspecial care.

               

              Any other ideas or clarifications?

              • 4. Re: InDesign Transparency issue
                Peter Spier Most Valuable Participant (Moderator)

                When you say "black and white" do you mean Bitmap mode (only 100% black or 100% white pixels), grayscale (black channel only) or RGB with some sort of filter applied to make it "appear" as a black and white (sounds like the last). Tell us the color mode listed in the Infor panel when you select the image.

                 

                And no, this is not a translation error in ID. It's expected behavior with color management, but waht I said only applied to grayscale images, and changing the blend mode to RGBmakes it sound like the image may actually BE RGB.

                • 5. Re: InDesign Transparency issue
                  Chez Voz Level 1

                  I meant the images are grayscale.

                   

                  I'm migrating from Quark, which although very slow to render, had no strange things happen when applying a transparancy.

                   

                  A very odd thing happens that I don't understand - when I apply the transparency, the tif image gets lighter, but not as light as the 50% I'm applying to the box. If I send the box with transparency to the back, the tif remains grayed. Only when I delete the transparency box does the tif return to normal.

                   

                  When I add a color image, so now I have a grayscale and a CMYK image in the doc, and place a box with transparency applied,  only the grayscale image changes. The color image remains as I expect. Exporting to pdf creates what I see onscreen.

                  • 6. Re: InDesign Transparency issue
                    Peter Spier Most Valuable Participant (Moderator)

                    This is what I described in my first post.

                     

                    I haven't used Quark for years, so I don't know how it previews grayscale these days, but ID has essentially two levels of preview, "normal" or overprint. The normal preview uses a gamma 2.2 graysacle preview on screnn, but does not necessarily accurately display what the gray values will look like at output. Overprint Preview (which can be turned on from the View menu, or by turning on separations preview) shows the effects of overprints as well as reinterpreting the gray values as applied to the K plate in the CMYK working space, which is how they will output, and for many profile combinations this will result in a lighter on-screen preview of the grayscale image. Adding transparency to a page does not invoke Overprint Preview in it's entirety, but it does cause ID to redraw the grayscales as they are interpreted in the working CMYK.

                     

                    What profile are you using for the grayscale when you edit in Photoshop? Are you embedding it? The most accurate way to work with grayscales is to actually load the Black Ink channel of the CMYK  output space as the gray profile.

                     

                    The bottom line here is that the changed preview on screen is correct. Try a test with the same grayscale image on two different pages (not facing), and add some transparency to one page to change the preview. Export to PDF and compare the two pages.

                    • 7. Re: InDesign Transparency issue
                      rob day Adobe Community Professional & MVP

                      #29 of this thread might help with your Color Settings setup.

                       

                      http://forums.adobe.com/message/5710903#5710903

                      • 8. Re: InDesign Transparency issue
                        rob day Adobe Community Professional & MVP

                        Michael, I changed the transparency blend space from CMYK to RGB and that changed the onscreen appearance. I exported to pdf, ignoring the warning message about the RGB, and in that case, the transparency is OK (although I don't know if there will be problems sending this to the printer.

                        There will be a problem at the printer if you set the Transparency Blend Spce to RGB and expect the grayscales to output as grayscale. If the blend space is RGB gray objects on a page with transparency will convert ot 4-color.

                        • 9. Re: InDesign Transparency issue
                          Stacia Garlach

                          I just had the same thing happen and found this thread. After reading it, I changed my grayscale images to CMYK in Photoshop, then updated the links in InDesign. They still appear grayscale, but that solved the problem. Thank you!

                          • 10. Re: InDesign Transparency issue
                            rob day Adobe Community Professional & MVP

                            They still appear grayscale, but that solved the problem. Thank you!

                            They won't print as grayscales.

                            • 11. Re: InDesign Transparency issue
                              Stacia Garlach Level 1

                              OK for my purposes - it's a 4C job. Thanks though!

                              • 12. Re: InDesign Transparency issue
                                rob day Adobe Community Professional & MVP

                                OK for my purposes - it's a 4C job. Thanks though!

                                 

                                4-color grayscales can be difficult to keep neutral because there's CMY along with the black. If the profile you use to make the conversion isn't exact for the printing conditions you'll likely get a color cast. Usually when you print grayscales as 4-color you want to separate using a profile that has a heavy black generation.