Have you ever printed a colour image and wondered why it didn't look quite right? That deep blue sky with distant hills and forests looked so good on the monitor... is what you see never what you get?
You've just come across one of the problems of colour management on the Mac. Without colour management, reproducing an image from a digital camera on an inkjet printer can require a lot of trial and error, and a fair bit of wasted ink and paper.
The basic difficulty is that colours on your monitor are produced by the addition of red, green, and blue light, while your printer mixes coloured inks (typically cyan, magenta, yellow, and black) If all the colours on every monitor were the same, and all printers used the same ink and paper, it would be easier to match things up. Unfortunately even identical printers are subtly different, and monitors change their characteristics as they age.
Unexpected changes in colour can lead to costly mistakes and delays in projects. In commercial printing, a great deal of effort goes into colour management - a whole industry is devoted to getting things right. Although that's fine for business, what about the casual user or photographer who just wants to improve their photos?
The Mac Does It Again -- The good news is that in owning a Mac, you have a system with all the best in colour management technology built right into the operating system. As one of the founders of the International Color Consortium (ICC) in 1993, Apple helped to create open standards and neutral file formats, which resulted in ColorSync. And in Mac OS X, there are some powerful new tools for handling colour (older Mac systems have ColorSync, but not the range of tools).
The essence of managing colour depends on profiles for each device. A profile contains a wealth of data describing the characteristics of a piece of hardware, whether it's a camera, scanner, monitor, or printer. For example, a profile includes the range of colours that a device can represent (known as the gamut). Using the profiles, ColorSync translates data between the capabilities of different devices ensuring a consistent handling of colour information.
The best bit is that for most users, the built-in colour management is invisible. When you plug in your digital camera and transfer images to iPhoto, all the necessary conversions are carried out for you. The appropriate colour information is assigned to the image file during import. Then, as you look at the image, ColorSync matches the image to your monitor for display and to your printer when you print it. And again, ColorSync takes care of this behind the scenes without any input from you. But that's not to imply that you don't have some control.
The ColorSync Utility (located in the Utilities folder in your Mac OS X Applications folder) enables you to see which profiles the system has allocated to devices, and helps you repair broken profiles. With it you can examine the contents of profiles and even view the gamut of the profile (represented as a solid 3D volume you can rotate). The volume view indicates the number of colours that a device can represent. Try looking at some of the standard profiles on your system and you can quickly see the variation between devices.
Each of your devices has a registered profile for ColorSync. Some may have several profiles available and allow you to choose new ones. The ColorSync preferences pane in System Preferences enables default profiles for files that do not have colour information associated with them.
So if it's all done for you, why do the results sometimes fail to impress? It all comes down to the accuracy of the profiles. Most devices come with generic profiles that provide only an average fit.
Start with the Monitor -- If your monitor is not displaying the right colours, any attempt at getting your prints right becomes much more difficult. The Displays preferences pane in System Preferences contains the usual settings for display resolution, but it also has a Color tab for selecting ColorSync profiles. If your hardware supports it, the panel can access information directly from your monitor.
You can choose from a collection of monitor profiles for your display. It's best to pick one that matches the monitor, such as Apple Studio Display if that's the monitor you own. You can also customise and improve the accuracy of the profile by clicking the Calibrate button, which fires up the Display Calibrator application and walks you through steps that determine how color should be displayed. Keep in mind, though, that calibrating using this method is somewhat dependent on the vagaries of your vision. There are other utilities that do a similar job, such as Adobe Gamma, which used to come with Photoshop. SuperCal (for Mac OS 9 and Mac OS X) does the same thing in a bit more detail. These approaches are certainly better than no calibration at all, and I'd recommend that you run Display Calibrator if you're planning to work with any kind of images on your Mac.
For the ultimate in color accuracy, hardware assistance is required. You can buy a colorimeter that determines accurate colour profiles by precisely measuring the colour output of your monitor. A few colorimeters to look into include Gretag Macbeth's $250 Eye-One Display, ColorVision's $230 Spyder, or Monaco Systems' $300 MonacoOptix.
Why Your Colour Prints Can Look Wrong -- Setting your monitor to display accurate colour takes you only halfway to achieving better photo prints. Your printer must also output colour correctly, which adds another layer of complexity. Printer drivers have their own internal profiles that combine with paper settings and any driver adjustments to produce a "best guess" of how the image should be printed. The printer manufacturers provide settings to cover all the options, so their drivers are not optimised for any one particular setup.
Some printer drivers install additional profiles for specific papers that you can select in the ColorSync utility. If you are using the printer manufacturer's inks and paper, then it's worth experimenting with their ColorSync profiles. Inks and papers from other manufacturers will never work quite the same. There are some excellent third party inks and papers that, despite what some printer manufacturers might have you believe, will not ruin your printer. For example, I use a specialized Small Gamut ink set from Lyson for printing black-and-white photographs.
If you print from an application such as Photoshop Elements you have the option of using the additional profiles provided with some printers. That's not necessary, of course - you can always just accept the defaults - but if you choose to adjust the colour management for a particular image, you must decide where the colour management will apply in the printing process. There are three options. First, if your application does its own color management, you can use it, but you must also make sure to disable colour management (the No Colour Adjustment radio button) in the printer driver. Second, you can choose to let ColorSync do your colour management. Third and finally, you can leave the colour management task to the printer driver itself, which uses whatever default settings the printer manufacturer built in. With the first option, it's important to apply only one profile or your results will be terrible. As an analogy, imagine translating from English to Spanish directly as opposed to going from English to Japanese to Spanish. The fewer intermediate steps, the better.
As you can see, we've moved some way from simply selecting Print in your application, and the need to consider exactly where the colour management takes place adds complexity. Given what ColorSync and the driver's built in profiles can do for you, why not just leave it at that?
The benefits come with having a profile that is customised for a particular ink/paper/printer combination. Some third-party ink and paper suppliers (such as Lyson) provide profiles for some of their products - many do not. For the best quality prints you need custom profiles. In the next installment of this article, I'll show you how I was able to get a more accurate profile of my inkjet printer using ColorVision's PrintFIX custom profiling device and software.
[Keith Cooper is a photographer and long time Mac consultant. He also teaches photography and digital imaging to adult classes. More photography and Mac information can be found at his Web site.]