15 Replies Latest reply on Nov 8, 2008 10:26 PM by (Rick_McCleary)

    New CMYK conversion behaviour in CS4 ?

    Level 1
      I posted this in the Photoshop Windows forum and did not get much of a response. Perhaps one of you colour 'geeks' might know the answer..

      With previous versions of Photoshop, when an RGB image in a given RGB colourspace was converted to CMYK by choosing Mode -> CMYK, it would convert to whatever CMYK was set as the Working Space in the Color Settings. With CS4 there's a warning dialogue that appears that makes one wonder if CS4 is behaving differently. It now says:

      "You are about to convert to CMYK with no color profile. This may not be what you intend. To choose a profile, use Edit > Convert To Profile".

      The resulting CMYK would certainly *have a profile* as it's the default selected in the Color Settings > Working Spaces menu. It's the same as if I had a CMYK file and selected Mode > RGB. This would convert from CMYK to whatever default RGB space is set in the Working Spaces menu. Yet from CMYK to RGB there is no such warning. Why not... the same logic would seem to apply.

      I'm confused about the point of this new warning?
        • 1. Re: New CMYK conversion behaviour in CS4 ?
          Level 1
          Russell -

          Check you Color Settings. Your CMYK color management policies are probably set to OFF. Not a good thing. Try choosing a preset like North America Prepress 2 (which sets color management policies to "preserve") and then do Mode > CMYK again. This time, you'll get the same warning box but with USWebCoatedSWOPv2 shown as the profile to which the file will be converted.

          This warning box is new to CS4. It's meant to keep users aware of what's happening, so no "blind" conversions occur.

          HTH
          • 2. Re: New CMYK conversion behaviour in CS4 ?
            (Marco_Ugolini) Level 1
            The wording in the warning dialog box sounds a bit infelicitous -- you are correct that the conversion would actually be using the default CMYK color space selected in the application's Color Settings. It would
            i not
            be using "no profile".

            But I'm sure that what the warning means to convey is that by converting via Image > Mode > CMYK one may not be fully aware what the conversion's destination color profile is -- whereas, by using Edit > Convert to Profile the user both knows and directly controls exactly which destination profile, rendering intent and black point compensation policy are being employed in the conversion.

            I don't think there's anything more than that going on. There is no effective difference in the results from what happened in previous versions of Photoshop -- just an added warning.

            As to why the warning is not coming up in CMYK-to-RGB conversions, it may be either a slip or a decision on the part of the Adobe team that a warning in this case is not as crucial.
            • 3. Re: New CMYK conversion behaviour in CS4 ?
              Level 1
              Hi Marco -

              > you are correct that the conversion would actually be using the default CMYK color space selected in the application's Color Settings

              Not if the CMYK color mgmt policies are set to 'off".

              > It would not be using "no profile".

              It would be using no profile, resulting in an untagged CMYK.
              ed - I mis-"spoke". It is using a profile to make the conversion - the designated CMYK working space - but it is not embedding that profile into the file, resulting in an untagged CMYK.

              Try it out. It's actually a very nice little addition that keeps the user abreast of what's happening behind the scenes. Avoids colorful train wrecks.

              > As to why the warning is not coming up in CMYK-to-RGB conversions, it may be either a slip or a decision on the part of the Adobe team that a warning in this case is not as crucial.

              I believe it's more to do with the fact that there is far less (ed, potential) damage from a blind CMYK-RGB conversion than the other way around.
              • 4. Re: New CMYK conversion behaviour in CS4 ?
                (Marco_Ugolini) Level 1
                Hi Rick.

                Conversions are always made to a destination color profile.

                Even with the Color Management Policy set to "Off" in the Color Settings, the destination profile is its selected default CMYK profile. The resulting image file is not tagged, but the color numbers are those of the default CMYK profile.

                So, to be precise, though the resulting file is untagged, it still uses the default profile.

                By the way, how does it avoid "colorful train wrecks" to save the resulting CMYK file as untagged?
                • 5. Re: New CMYK conversion behaviour in CS4 ?
                  Level 1
                  > Even with the Color Management Policy set to "Off" in the Color Settings, the destination profile is its selected default CMYK profile. The resulting image file is not tagged, but the color numbers are those of the default CMYK profile.

                  Your absolutely right, See my edited post.

                  > By the way, how does it avoid "colorful train wrecks" to save the resulting CMYK file as untagged?

                  It's not saving the file untagged that avoids train wrecks. Exactly the opposite - it's the warning that avoids train wrecks. It gives the user a chance to save themselves from a trip into the ditch by warning them that the file will be untagged if they proceed. Prior to this warning box being triggered by Mode>CMYK (CS3 and previous), the file would be converted and left untagged - all under the hood. The unwitting user would be screwed.
                  • 6. Re: New CMYK conversion behaviour in CS4 ?
                    (Marco_Ugolini) Level 1
                    Rick McCleary wrote:

                    >It's not saving the file untagged that avoids train wrecks.

                    We agree. My apologies for having misunderstood your meaning, Rick.
                    • 7. Re: New CMYK conversion behaviour in CS4 ?
                      Level 1
                      No problem. And no apologies necessary. I was unclear.
                      • 8. Re: New CMYK conversion behaviour in CS4 ?
                        Level 1
                        Thanks for your responses. I'm wrapping my head around "what were they thinking" when Adobe decided to add this warning. Still I think it would have been more appropriate to say "will be converted to your default CMYK colorspace".

                        FWIW my default CMYK setups are client specific and I have Color Settings presets for each client based on their printers needs. It's a lot faster when you have many dozens of images to retouch, colour correct and convert to modify the default Colour Settings setup and just use Mode -> CMYK to get there. I find converting to profile, which involves choosing from a list, more error prone for me (I work very fast).

                        Each to their own and whatever works.... :-)

                        Russell
                        • 9. Re: New CMYK conversion behaviour in CS4 ?
                          (Marco_Ugolini) Level 1
                          Russell Proulx wrote:
                          >Still I think it would have been more appropriate to say "will be converted to your default CMYK colorspace".

                          Or "profile". I agree.

                          >It's a lot faster when you have many dozens of images to retouch, colour correct and convert to modify the default Colour Settings setup and just use Mode -> CMYK to get there.

                          Make sure that the choices of rendering intent and black point compensation in your Color Settings are those that you wish to be using, since those are the ones that are applied to conversions made by using Mode > CMYK.
                          • 10. Re: New CMYK conversion behaviour in CS4 ?
                            Level 1
                            > Make sure that the choices of rendering intent and black point compensation in your Color Settings are those that you wish to be using, since those are the ones that are applied to conversions made by using Mode > CMYK.

                            I'm one of those 'Custom CMYK' setup guys ... all is good :-)

                            Russell
                            • 11. Re: New CMYK conversion behaviour in CS4 ?
                              (Marco_Ugolini) Level 1
                              Russell Proulx wrote:
                              >I'm one of those 'Custom CMYK' setup guys ... all is good

                              One of those, eh? Well, good luck to you.
                              • 12. Re: New CMYK conversion behaviour in CS4 ?
                                Level 1
                                > I'm one of those 'Custom CMYK' setup guys ... all is good

                                ... I don't need no stinkin' rendering intents!! :-) :-)

                                RIck
                                • 14. Re: New CMYK conversion behaviour in CS4 ?
                                  Level 1
                                  You do what works best for you.. if it ain't broke...

                                  Why do I suddenly feel like Jack Nicholson in Mars Attacks addressing the Martians asking "why can't we all just get along??"....and then Ack Ack!!

                                  Russell :-)
                                  • 15. Re: New CMYK conversion behaviour in CS4 ?
                                    Level 1
                                    > You do what works best for you.. if it ain't broke...

                                    ... I hear ya.

                                    "Why can't we just get along?" Rodney King also.
                                    A question for the ages.

                                    Most of all, keep smiling. :-) :-) :-)