RGB to CMYK in Photoshop. HELP!

Discussion in 'Mac Apps and Mac App Store' started by leekohler, Jan 27, 2005.

  1. leekohler macrumors G5

    leekohler

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    #1
    Hey guys,

    I have a major problem. I can't get my blues to look right on a certain image when I convert it from RGB to CMYK in Photoshop. The image is almost all bright blue and when I convert it to CMYK, the blue just flattens. This is for a client of mine and I made the mistake of first e-mailing an RGB image for his approval. He loved it of course and now I'm freaking! I've tried everything: brightness/contrast, curves, levels, hue/saturation and it all just ends up looking the same. Any suggestions? You guys could be saving my life here.
     
  2. wordmunger macrumors 603

    wordmunger

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    #2
    Can you use a spot color? You might be able to make a more convincing graphic with a couple of spots than full CMYK. If you're stuck with CMYK I can't help you. Maybe someone else can.
     
  3. leekohler thread starter macrumors G5

    leekohler

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    #3
    Well-It's actually a photo I took with a digital camera. I'm not sure how I could use a spot color with it.
     
  4. tech4all macrumors 68040

    tech4all

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    #4
    Just some questions to get more info

    Is this going to be printed? (I assume it is since your in CMYK)

    If it is going to be printed, would you do it yourself or take it to a printer?
     
  5. leekohler thread starter macrumors G5

    leekohler

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  6. Chip NoVaMac macrumors G3

    Chip NoVaMac

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    #6
    Don't have any quick answers for you, but had a similar experience in doing our Holiday insert. I had searched for a graphic and sent it out RGB, got approved. Then did the layout in CMYK, the proof came back from the printer, with the colors really flattened out. I learned my lesson from that, as you did too.

    Did salvage the image by going in and playing around with the levels and curves to come as close as I could. In the end my boss was happy.
     
  7. tech4all macrumors 68040

    tech4all

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    #7
    Usually RGB colors are more vivid that CMYK colors. Also, you really shouldn't go by what the screen shows you as the actual printed piece may be much different depending on paper type and. I just had some businesscards, letterheads, and envelopes printed for myself about a month ago or so and I used 1 Pantone/spot color. On screen the PMS (Pantone Matching System) has an equvilent CMYK number that looks just like the Pantone color. However when I went to my printer they had a Pantone swatch book and the acutal PMS color Vs. the CMYK color were much different from eachother in contrast to how they looked on screen. Plus you have all these color modes in Photoshop, Illustrator, InDesign, Acrobat, and even the OS itself; thats a lot of varibles.

    What I would guess you can possibly do is print the blues on a single plate that uses a PMS color that is fairly saturated. I'm not a total expert on this, but that seems like a possibility.

    Also have you tried to play with the Blue/Cyan channel saturation. Try messing around with Selective color/Channel mixer under Image>Adjustments. Perhaps selecting the blue areas would be better so you dont over do the blue in other colors. There's a lot of ways to do this, just gotta play with it and see what you come up with.

    Anyway you can post the pic? Or is it confidental (sp?)
     
  8. leekohler thread starter macrumors G5

    leekohler

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    #8
    Yeah-here it is. Maybe this will help. And this is kind of sensitive-it's for a film festival, so be discreet. :)
    Sorry it's so small. The website would only let me do 100k
    Edit: Maybe this one is better.
     

    Attached Files:

  9. leekohler thread starter macrumors G5

    leekohler

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  10. tech4all macrumors 68040

    tech4all

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    #10
    What you may be able to do is turn the picture into a duotone/tritone. And have it so that you have one of the 'tones' be a bright Pantone color; which would be the blue in picture, then that bright blue Pantone color will be used for all the blues, but the halftone dots will vary in size to allow the color to be screened back to allow for the different intensities. Then choose other colors/Pantones that could go with the rest of the picture. Finally play around with the colors you choose till they look close to the original RGB version.

    The final product with Pantone color probably won't have that "glow" look, but you can try to get it a more satutarated look with a Pantone color that you may not be able to get with CMYK when printed. I have never done this before (I've done duotones on screen, I mean), as I haven't printed with a Pantone being one of the 'tones', but I have designed with a Pantone color and printed that a printer (as said in previous post). Hope that makes sense, it should work in theory. Also I would talk to your printer and see what they might suggest as well.

    Good luck!
     
  11. leekohler thread starter macrumors G5

    leekohler

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    #11
    Thanks, but I tried That avenue already. It was one of the first ones I thought might work. Ugh-I've been working on this all night and I am getting closer, but running out of paper and ink. :)
     
  12. leekohler thread starter macrumors G5

    leekohler

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    #12
    And I truly appreciate all your suggestions. You guys are always a huge help. I love this website. :)
     
  13. tech4all macrumors 68040

    tech4all

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    #13
    Why didn't it work? Couldn't get it to look right?

    Been there, dont that ;)

    I'm not certain as to what kind of printer you have, but (at least this is what my printer said), a "consumer" printer's results really won't look like what an offset press' results would look like.

    Maybe they have some sort of neon blue? or some special ink that is really saturated. course that probably cost a pretty penny.
     
  14. leekohler thread starter macrumors G5

    leekohler

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    #14
    No-the duotone/tritone thing looked really weird.

    I use an Epson Stylus Photo 1280. It's about as accurate as you can get without having your own print shop. It's always matched what I've gotten back from a commercial printer. It should, it cost $500. It's just frustrating-I've been doing this kind of work for several years and you always run into something new I guess. Oh well. I'll figure it out. Thanks again, I really appreciate the help.
     
  15. Eric5h5 macrumors 68020

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    Dec 9, 2004
    #15
    I work with CMYK, and what it basically comes down to is that RGB colorspace and CMYK colorspace aren't the same, especially with blue. Mixing cyan and magenta to get blue on a printed page just doesn't allow you to get that bright "computer monitor" blue, no matter what you fiddle with. Cannot be done. Sorry. The only choice, as others have said, is to try some special ink (but then it's not CMYK, of course). Oh, and don't use RGB for proofs anymore. ;)

    --Eric
     
  16. tech4all macrumors 68040

    tech4all

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    #16
    No problem ;) If you can't find a solution, maybe you can take it to the printer and see if they have any suggestions.


    Best of Luck! :)
     
  17. leekohler thread starter macrumors G5

    leekohler

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  18. leekohler thread starter macrumors G5

    leekohler

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    #18
    Thanks again you guys. :) And I AM getting closer!
     
  19. leekohler thread starter macrumors G5

    leekohler

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    #19
    Oh-and not that this was a fun way to get there, but I just noticed I became a MacRumors regular. I'm no longer a newbie!
     
  20. emw macrumors G4

    emw

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    #20
    Ah, the classic problem of RGB color space vs. CMYK color space. A couple of things:

    1. About using special colors - you may want to be careful as this will often result in an extra charge from the printer, if they can even print it. Choosing a Pantone color doesn't mean that the printer won't be forced to convert to process color anyway. And you will have no control over that conversion, so it may turn out worse than you expected.

    2. About converting from RGB to CMYK - the CMYK gamut is significantly smaller in certain areas (unfortunately, particularly blues) and there is nothing that can be done about it. The best thing is to understand the printing process used and convert to that in Photoshop using the Saturation rendering intent. Perceptual is generally best for RGB-CMYK conversions, but in your case you are trying to max out the gamut, so Saturation may do better.

    3. Regarding trusting your monitor - generally speaking, don't. Unless you've calibrated it carefully, this is often a mistake. Same with trusting your local ink jet proofer, although it sounds like you may have done a good job getting that to match your press runs.

    I wish I could help more - it's just pretty limited on what can be done at this point.

    Good luck!
     
  21. jaw04005 macrumors 601

    jaw04005

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    Location:
    AR
    #21
    Will your lab not convert the RGB image for you? Maybe for a fee of course. In the past, I've always contacted the lab and asked what they recommended I do with images that were giving me problems.
     
  22. leekohler thread starter macrumors G5

    leekohler

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    #22
    emw- I think you may have solved my problem. Thanks! It's getting there you guys! My blues are definitely getting more intense.
     
  23. tech4all macrumors 68040

    tech4all

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    #23
    Out of curiousity, which suggestion that emw gave, worked?
     
  24. leekohler thread starter macrumors G5

    leekohler

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    #24
    OK-I feel dumb now Tech4all, but his second suggestion is working better, combined with using curves and selective color. The blues are getting brighter now and printing rather well, just a little dark. But I think if I brighten slightly, it'll be OK. It seems like it was no one thing, but a combination of them.
     
  25. leekohler thread starter macrumors G5

    leekohler

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