Printer profiles and calibration

Discussion in 'Design and Graphics' started by nicrose, May 8, 2007.

  1. nicrose macrumors member

    Joined:
    Apr 11, 2006
    #1
    Hi, I'm a complete newbie when it comes to color management. I have just asked my printer guy to send me a copy of the printer profile so I can get started on a poster I'm doing for a client.

    1. Question is: What do I do with the profile once I have it??
    My monitor has been calibrated already.
    My home printer (an HP 1210 psc-all-in-one) is not calibrated.
    The photos for the poster are digital and have an embedded profile called sRGB IEC1966-2.1. I have no idea what that means. Well, except that sRGB is used for the web or something.

    2. Where to I go from here? My poster will have some very large photos (possibly as big as 17" by 25", and they have to look good. I don't want to see green skin, or any of that other bad stuff I usually get when I cross my fingers and hope for the best.

    3. Two of the photos are portraits of a young man of (Asian) Indian descent (light-skinned, tannish, paler undertone) standing outside in front of a brick wall or a green-tinged glass window. The others are photos of young men of Asian Indian descent (tan skin, not brown skin) dancing in very colorful clothing on a lawn or pathway at a park. These photos were taken when the sun was fairly low in the sky (but not sunset) so there are lots of long shadows and high contrast in terms of highlights and shadows in the bushes and trees, and in the folds of the men's clothing. There is no sky in the pics, only grass and bushes. I want to be able to keep as much of the bright color in the men's clothing as I can, but also make sure their skin tone is accurately produced. For all the pics, the most important thing is I want to get the skin right. The bricks/glass can look somewhat different than what I see on screen. The grass has to look normal, of course.

    I don't have much of a photo background other than what I learned in B&W beginner and intermediate, so be gentle with me! ie) I 'm going to freak out if you start using weird vocabulary, because I don't have a lot of time. I'm a designer and painter, not a very good photographer, but I believe in quality.

    Thanks for any help.

    PS, I do own Dan Margulis's Professional Photoshop 5th Edition, so if you need to refer me to some pages in that, that's fine.:)

    Nicrose
     
  2. nicrose thread starter macrumors member

    Joined:
    Apr 11, 2006
    #2
    more info.

    by the way, the portraits of the young man look good to my eyes when viewed on my calibrated mac. I just want to make sure they stay that way when printed.

    the other photos of the men are okay, too.


    nicrose
     
  3. nicrose thread starter macrumors member

    Joined:
    Apr 11, 2006
    #3
    color management issues

    Actually, from taking a careful look at the portrait photos, I realize that there is a greenish tone on the skin, and that even the man's black clothing looks a little greenish. So, i need to figure out how to remove the green color cast in the skin. I used auto color, but the guy's face got slightly too pink-looking, although his shirt finally looked ok (a very dark gray).

    I also still need help on calibrating my image to the print shop's printer profile. It is going to be a poster, digital printing.

    I've been looking online, but i'm at a loss as to what to do. This is a confusing topic.

    Nicrose
     
  4. emw macrumors G4

    emw

    Joined:
    Aug 2, 2004
    #4
    Since you have a profile of the printer/press used to produce the picture, you'll want to use Photoshop's "Proof Color" option. In order to do this, make sure that the profile is loaded into the correct folder (Library:ColorSync:profiles:Recommended).

    In Photoshop, go to View>Proof setup>Custom.

    In the Device to Simulate drop-down, choose the supplied profile you loaded above. I'm assuming it's a CMYK profile, so you'll want to use the Perceptual Rendering Intent. You'll also likely want to use the Simulate Paper Color option to see how it will actually look on the stock he's calibrated to. If you want to assume he'll print on stock that is basically bright white, you could leave this off.

    Curious, though, about how you calibrated your monitor. Your printer may be a little more difficult, depending on the tools it came with. I'm guessing none.

    The embedded profile simply describes the color space that the pictures are currently in - the sRGB space is common for digital photos. The way profiles work is that the image profile, in this case an RGB profile, contains information on how the RGB colors map to a device-independent color space - LAB. The destination profile shows how LAB color map to the device's color space (in this case, likely CMYK). So what essentially happens is that Photoshop will take the colors that are in the RGB image and map them via the LAB color space to the CMYK colors using the rendering intent you specify. Perceptual is best for these since the RGB color space is significantly larger than the CMYK color space and perceptual attempts to maintain the general "feel" of the image during translation.

    Here's a look at the comparison of sRGB (wireframe) to a standard sheetfed CMYK profile. You can see how they don't match up exactly:

    [​IMG]

    Once you've done the profile thing and proof setup, make sure that you have View>Proof Colors checked. If the guys still look green, then I'd do some selective color or hue/sat adjustment layers to correct the skin tones.
     
  5. dogbone macrumors 68020

    dogbone

    Joined:
    Sep 16, 2005
    Location:
    S33.687308617200465 E150.31341791152954
    #5
    @=nicrose

    If you have Dan Margulis' Professional photoshop then I would suggest that you read it. Don't worry if you don't understand it at first, as long as you understand the concepts.

    Back to your printers, most printshops wouldn't know what to do with a profile anyway. You will either get your print done as a laser print or an inkjet, usually if it is over A3 size it will be an inkjet.

    Know this: A home printer needs images that have an RGB profile even though they use CMYK inks because they do their own CMYK conversion on the fly.

    Commercial printers whether Laser or Inkjet use images that have already been converted to CMYK. You can send them an RGB file and it will convert on the fly but it won't be pretty.

    What I would suggest you do is this... get your print how you want it to look then go to the menu in photoshsop and select Image>Mode>Convert to Profile... which will bring up a dialog box. I would suggest that you select US Web Coated (SWOP) v2

    Depending on the gamut of your original you may or may not see a colour change when you convert to CMYK, (see Dan's book for further info)

    I would suggest that after you have converted the file to CMYK (SWOP v2) that you take it to your printer and run out an A4 print which will be pretty cheap. Most printers will have their internal stuff calibrated to each other so that if a print looks good on their A4 laser it will look good on their inkjets.

    Hint: if you set you CMYK working space in photoshop to be US Web Coated SWOP, then you will not have to go to the "convert to profile" dialog box, you can simply select "CMYK colour" from the Image>Mode menu.
     
  6. nicrose thread starter macrumors member

    Joined:
    Apr 11, 2006
    #6
    thanks, emw

    emw, your explanation is very helpful. after reading your response several times, I think I get it. it sounds like LAB is the translator for converting the file so it goes from looking good on my screen to looking good on the poster. i still do not have the printer's profile but as soon as I get it, I will try your advice. thank you so much. this calibration stuff so difficult to understand.

    the only thing is, what do i do to remove the green color cast in these photos? are there any good tutorials out there that explain how to remove green color cast on skin/clothing?

    nicrose
     
  7. nicrose thread starter macrumors member

    Joined:
    Apr 11, 2006
    #7
    trying to grok the meaning of all this calibration/profile stuff

    N. says: so you seem to mean that I shouldn't bother with the printer's profile because this is not cmyk offset printing. instead i should convert the file to US Web Coated (SWOP) v2, then convert to cmyk after all edits have been made to image.

    N: Without doing any edits on the image, I converted it to cmyk and it looks almost the same, just very slightly darker, but no really noticeable changes in skin tone or anything else important. So I guess I'll be okay when converting to cmyk in the end.

    N: unfortunately, the printer guys will be sending this job out to some other printer company, so i doubt it will do me any good to do a trial run print.
     
  8. dogbone macrumors 68020

    dogbone

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    #8
    No, all I'm really saying in that para you refer to is that your home printer uses an rgb profile and theirs uses cmyk. In an ideal world you should just be able to give them your sRGB file and they should open it in photoshop looking as it should and then *they* should do the CMYK conversion. That would make more sense and be better for everybody. But that is not how it is, *they* want you to do the conversion and if it doesn't come out right then it's not their fault, or at least that's how they'd like to see things.


    As you will discover from Dan's book only colour that cannot be reproduced with cmyk inks. This is usually bright blues. Skintones are well within cmyk gamut and most normal subjects are too.

    All you can ever do is set a job up properly, if it is subcontracted out and it goes wrong it's the responsibility of the person you gave the job to, so it's still good to run out a proof on their machine. After all if it looks right on theirs and it comes back wrong they can't very well say, "oh, you proofed it on our machine, which is a complete piece of crap that cannot be relied on, even though it looks perfect on the print and your monitor", can they?

    All you need to do with the print shop is bluff them into thinking you know what you are doing, then they'll get nervous and make sure it is done right. Otherwise if they think you don't know and something goes wrong they'll just tell you anything. So trust Photoshop, it's pretty bloody good with a well set up monitor, a standard us web coated swop v2 will be perfectly acceptable 99.9% of the time, even on a sheetfed press.
     
  9. nicrose thread starter macrumors member

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    Apr 11, 2006
    #9
    color management confusion...the continued saga

    1.
    Nicrose responds: Hi, I calibrated my monitor using the Display Calibrator Assistant in the System Prefs. (I'm using a MBP). Should I set the Color Setting in Photoshop to the .icc profile that I created, or the Adobe RGB (1998)? Is my profile always being used in photoshop, whether it's selected or not?

    2.
    So is this process that you're discribing going to convert my file to cmyk? If not, at what point do I convert it to cmyk?

    3. I spoke to the printer about how can I be sure the images on the poster will print as I see them onscreen. He said don't worry. Well, I don't take things on faith. I see this poster as training for the future, when clients will expect quality, and will be pissed off if they see anything different from the pdf I send them. I'll be mad, too. The printer said I could make a proof at his shop. Well, since he's sending it out to someone else, that's not going to do me any good. I already asked him for the profile of the printer that he is sending it out to and he e-mailed me the file specs instead. I think he misunderstood me. Should I use the word "printer profile" or some other word? Is it not likely he will give me his subcontrator's printer profile?

    4. What about copying and pasting images into the poster? Are those images going to suddenly have a new profile in them? I'm creating the poster in Photoshop.

    Thanks.
    -Nicrose
     
  10. Father Jack macrumors 68020

    Father Jack

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    Ireland
    #10
    If you are printing at home you dont convert to cmyk !!!:eek:

    FJ
     
  11. decksnap macrumors 68040

    decksnap

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    Apr 11, 2003
    #11
    If he said he'll make a proof at his shop, that is good. That means you can approve the proof and he will send a copy of the proof to whomever is doing the final print. It will be their responsibilty to match the proof.

    Also note that 'matching the PDF you sent the client' is a bit more tough than it sounds, simply because that PDF will look different that it should on the client's uncalibrated monitor, and on their printer as well if they print it out. You should make the client aware of this.
     
  12. nicrose thread starter macrumors member

    Joined:
    Apr 11, 2006
    #12
    match the proof

    yeah, you've made a good point there. Mmm. I guess I assumed that I would be taking full responsibility for the color by approving/rejecting the proof myself, but by having the client be the one who gives it the official seal of approval, I guess that leaves the final decision up to him. So that's good. That's how I cover myself then. Because I don't want to be responsible for paying ptg. costs myself.
     
  13. emw macrumors G4

    emw

    Joined:
    Aug 2, 2004
    #13
    Sorry, I've been away for a few days, but I wanted to respond to these questions briefly. My apologies if it's a little late.
    Your monitor profile will always be used in Photoshop as the "view-through" profile. Any colors will be displayed through your monitor profile. You do not need to set it up as your working space in Color Settings. More on that in a minute.

    This will not convert your image, which I should have mentioned previously. It will simply allow you to see what your image will look like when you convert it. To do the conversion, use Edit>Convert to Profile...

    To be honest, it doesn't sounds like this guy really has a good concept of "color management". I'd suggest that you could probably get by with finding out what printing/paper he's using (probably sheetfed coated stock) and simply use a generic profile for the conversion, such as the sheetfed coated CMYK profile in Photoshop. By giving him a CMYK image, you remove the conversion aspect from the process. That is, if he uses some strange conversion scheme in his RIP to take your RGB to some generic CMYK, you may get something completely different than you expected.


    What I would suggest is that any image you're going to use in a single project/poster be converted to a standard Photoshop Working Space. This could be Adobe RGB or sRGB or whatever, but if they're all in the same space when you put them together, then the conversions tend to go more smoothly.

    As for having the client be the final decision maker - that is the best way to go. But it will be your responsibility to give him something that looks close to what you think he will approve.
     

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