7 Replies Latest reply: Jan 12, 2008 4:48 PM by F Shippey
Lars Farm Level 1 Level 1 (45 points)
Is there a way to convert rgb (jpeg) pictures to CMYK within Aperture?

I'm using Pages08 to prepare a CD-booklet. The end result should be a PDF with colorspace CMYK for printing at the CD-pressing plant. I keep my pictures (rgb/jpeg) in Aperture. Pages can export to PDF, but it'll be rgb. I open the pdf with Illustrator (I have Illustrator, but not full Photoshop), page by page and set the colorspace to cmyk. This does not alter the color space of included pictures. So, I need a way to convert pictures to CMYK. Can Aperture do it, how? If not Aperture, can Colorsync do it, how?


Macbook Pro, Mac OS X (10.4.10)
  • Howard Prendergast Level 1 Level 1 (15 points)
    Hi Lars, I am having the same problem. I cannot seem to find a way to export as CMYK. I can "on-screen" proof as CMYK, but in the "export presets", only the RGB and grey-scale presets come up. I have gone into the Colour-sync folder and dragged the Adobe 5 CMYK profile to the first level, but it didn't show up in the profile list in Aperature, even after restarting the application. I am going to have to convert in Photoshop to sent to my client.
    If you get any data about this, please post. I will do the same.
    I just tried exporting to Photoshop and saving back in Aperature. I created an export profile with "Use Source Profile" selected. It gave me an error.
    This is an definite shortcoming of the program that needs to be remedied. If it can export RGB, then why not CMYK!??
    That's al. Howard
  • SierraDragon Level 4 Level 4 (2,695 points)
    AFAIK Aperture cannot convert an image to CMYK. For that you need to open in Photoshop.

    A bit of an Aperture shortcoming, but IMO not as significant as it might seem. In general, simplistic conversion to CMYK is inappropriate/wrong anyway (IMO). Typically RGB (the form of all digital capture and all display) is converted to CMYK (the form of all final hard copy printing) because print shops insist "give us CMYK." However, without color managing the CMYK conversion process to match the precise CMYK output printer hardware, basic un-color-managed conversion to CMYK is a false premise.

    Hopefully Aperture v2 will fully support a comprehensive color management workflow that includes conversion to CMYK. But even if it does most photogs will be better served by dealing only with competent printers, providing quality hard copy proofs, and then saying "generally match this hard copy proof and make my RGB submission look good."

    Note that all photo quality inkjet printers expect RGB input and convert to CMYK on the fly. Submitting CMYK just entails an additional conversion.

    -Allen Wicks
  • JohnGrover Level 1 Level 1 (0 points)
    Here is the problem with saying CMYK is unimportant. I have been shooting professional digital images since 1995. From the beginning, printers and clients did not handle my RGB files correctly. Several decided never to use digital again. These images were quality images with a proof "go by print". The conversion to CMYK is a compromise, and the image must be optimized for the offset printing process. A professional photographer either needs to do it himself or hire it out because otherwise the result will be a lost client.
    Aperture needs to at least be able to export the format "AS IMPORTED". CMYK versions that I spent time creating originally are now damaged goods because Aperture exports them as RGB. The RGB format requires a reconversion and more time every time the client requests an image. One day, everything may be web or inkjet printed. Until then, the PROFESSIONAL image making world revolves around knowing, optimizing and being able to export CMYK!
  • julesselmes Level 1 Level 1 (10 points)
    A good CMYK conversion can not be obtained by a one size fits all type of button! Surely it is best to keep your work flow in RGB until it is in the hands of the experts at the printing press. I have worked on big jobs where we have used an RGB workflow through to press, using Indesign and the final out put was perfect. Just as we have had to learn over the last few years, clients/designer's must too. But that is for a whole new topic in the right forum!

    This massive area of reproduction is best left to the experts or a program with the pedigree of Photoshop; even though Photoshop ships in Europe with it's default set up for American Press' and so does a poor job unless it is sorted out; back to designer's messing up our work (I too had a complaint in the past about my files but found out they had not set up Photoshop properly!)

    The CMYK conversion is a complicate action that needs to take into account many printing factors. For example the K plate (from CMYK which represents the black ink used to print) produced from a conversion for printing on a coated stock (paper) will be denser than one for uncoated paper which will be paler. This is because the ink will sit on the uncoated paper nicely but will be soaked up and spread on an uncoated paper. Then you need to know if it is a sheet press or web fed press. Imagine what happens to your lovely drop of ink as it hits a piece of paper flying through a web press at speed... And do you know what inks are being used as this affect the densities of the CMY plates. People don't realise it is not like the simple choice between J-Peg, Tiff or PNG.

    As Aperture users we seem to want everything to be done with a quick click of a few buttons and wangging a few slider's around. Do we all want Aperture to become an over bloated beast while trying to do absolutely everything like Photoshop has. Aperture is a good Raw handling photo management program. Rough around the edges maybe but it is getting itself sorted gradually and you can be sure with the might of Apple behind it it will rock by version 2 or 3. We are imaging craftsmen and craftswomen so it can take time to produce a work of art but we need to strive towards an efficient work flow but not slap dash convenience.
  • offtheroad88 Level 1 Level 1 (0 points)
    Well said. I worked in a government art department and we had all these old designers (opp's I'm 60 now) that would laugh at me using RGB. I was actually a Staff Photographer transferred over to the art dept. after the great Phd's shut down the Photo dept.
  • julesselmes Level 1 Level 1 (10 points)
    Oops! Typing error...
    "This is because the ink will sit on the uncoated paper nicely but will be soaked up and spread on an uncoated paper" Should of course be "This is because the ink will sit on the coated paper nicely but will be soaked up and spread on an uncoated paper"
  • F Shippey Level 7 Level 7 (21,500 points)

    Here is the problem with saying CMYK is unimportant.

    The problem is, CMYK is output DEVICE dependent - you can't really talk CMYK in a meaningful way without linking the discussion to a output device.

    (During my career as an imaging scientist at Kodak I derived my share of RGB<=>CMYK conversion matrices because all the original digital film scanners available (Scitex and Crossfield) output a form of CMYK data.)