RGB VS CMYK

Discussion in 'Digital Photography' started by Bill Wood, Sep 12, 2006.

  1. Bill Wood

    Bill Wood Guest

    Newbie here
    I'm finishing the editing on my book that includes my photos of stained
    glass works. I'm self-pubing this and was told by my printer that I need to
    convert my tiff images from RGB to CMYK in order to present printer with
    'trouble-free' files, thus keeping cost of printing down.
    QUESTION: A friend suggested that I get Adobe photshop to do this
    conversion, WHICH IT DOES DO..But...The photos seem to obtain a kind of
    dullness when this conversion is done. Am I doing this right?
    Thanks
    Bill
     
    Bill Wood, Sep 12, 2006
    #1
    1. Advertisements

  2. Bill Wood

    Jim Guest

    Which RGB to which CMYK? Has the publishing house furnished you with a CMYK
    profile for their printer? If not, all bets are off.

    I am assuming that you are looking at the files on your monitor. To have
    any hope of evaluating the CMYK image on your monitor, you should create a
    profile for it.
    You of course, do realize that the CMYK image must be converted back to RGB
    before the data gets sent to the monitor. This back conversion introduces
    the possibility of unwanted change.

    I would request proof copies of the images because there are too many ways
    for incorrect conversion otherwise. Besides, that is the real acid test
    anyway.

    Jim
     
    Jim, Sep 12, 2006
    #2
    1. Advertisements

  3. Bill Wood

    darkroommike Guest

    CMYK images will appear dull when viewed on your monitor after
    conversion but will also appear duller than the original RGB images when
    viewed in print since any CMYK colorspace is different from and has a
    smaller gamut than any RGB colorspace. (At least practically speaking.)
    Compounded with the different method of displaying the image: monitor
    vs printed image.

    You do need to chat further with your printer and find out which CMYK
    color space he is using, affected by the type of press, the inks he is
    using and the stock he is printing your images on. Photoshop will also
    help you to create separations (seps) that will fit any colorspace he
    might be using (simplified the separations are the layers in your CMYK
    version of your image, saved as separate files for Cyan, Yellow, Magenta
    and blacK--printers use K for black since some old timers called Cyan
    "Blue".)

    There are Photoshop books specifically written for pre-press, might be a
    good idea to bone up--my own experience is limited to shooting photos
    for a Real Estate Tab for a local paper, the colorspace we used for that
    included SWOP Uncoated Web "uncoated newsprint" for the paper type (I
    forget the rest, it was a long time ago and 4 versions of Photoshop).


    darkroommike
     
    darkroommike, Sep 12, 2006
    #3
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.