2 Replies Latest reply: May 10, 2008 12:09 AM by c.pfaffenbichler RSS

    rgb to cmyk out of gammut problem

    lister110@hotmail.com Community Member
      Im working on a retouch of some pints. The photographer has shot the pints and kept them raw files. When i open these i get gammut warnings. If I do a straight conversion to cmyk, the colour shift is quite bad and flatterns the image (pints are a nice golden orange before cmyk).

      Is there a good profile to use to convert these to cmyk and keeping the luminosity, though these images will be used on posters (prepress) etc..

      Thanks

      lister
        • 1. Re: rgb to cmyk out of gammut problem
          Neil_Keller Community Member
          lister,

          Once you compare the gamuts of RGB and CMYK, you will see it is impossible to properly render every RGB color in the smaller color space that is CMYK. You would need custom color touch plates, Hexachrome or some other variation of the color printing process to make up for CMYK's deficiencies.

          Bright, clean oranges, greens and purples probably suffer more than other colors. Colors closer to cyan, magenta and yellow fare better. Still, it is remarkable that you can get color as good as it is with just four standard printing inks.

          Neil
          • 2. Re: rgb to cmyk out of gammut problem
            c.pfaffenbichler Community Member
            Apart from the differently sized gamuts that Neil mentioned an additional factor that You might consider (if You havent already) is the Render Intent; mostly one needs only decide between Relative Colorimetric or Perceptual though.