Aperture: Color and gamma settings for print and web
Proper color settings begin at your camera, live or die by the calibration of your display, and end within the limits of your chosen output, such as web publishing, ink jet, wet lab processing (RA-4), or a CMYK offset press. In short, the goal is to work with an onscreen image that has the same colorspace, white point, and gamma bias as your printer or printing service. Aperture makes its role in this process very easy, but first things first...
Aperture, Photo Services
Become familiar with the colorspace presets available on your camera, such as sRGB and Adobe 1998. Use the RAW mode if your camera has one, because it will preserve all the color your camera has to offer. If there's no RAW, Adobe 1998 will capture more color than sRGB.
Calibrating your display
Display calibration is the foundation of your color work. You'd have to try real hard to make anything else have greater effect. If your display had a color cast, all your prints might come out looking blue, for example. Or if you choose the wrong gamma, your images will look too dark on the web.
You can get your display pretty close by using the Expert Mode in Displays preferences, but if people give you money to do this (or you just want to look professional), you should really consider a hardware calibration device such as the Pantone ColorVision Spyder, Gretag Macbeth Eye-One Display 2, or MonacoOPTIXxr. These mouse-looking devices hang in front of your display and measure its output with a sensor to create a profile that's perfectly matched to your display.
If you want to try your hand-eye coordination at the Expert Mode in the Displays preference pane, follow these steps:
- From the Apple menu, choose System Preferences.
- Click the Displays icon.
- Click the Color tab.
- Click the Calibrate button.
- Select the Checkbox for Expert Mode.
- Click Continue, read the "Choosing gamma and white point" section of this article (you'll need it), then follow the prompts until your done.
Choosing gamma and white point
During the calibration of your display, you will need to choose gamma and white point settings. The correct choice depends on how you are most likely to use your images. The best rule of thumb is this:
Unless you have a color management expert instructing you otherwise, select a 2.2 gamma and a D65 white point.
Because Windows PCs use 2.2 gamma, images edited in the traditional Mac 1.8 gamma will appear incorrectly to most viewers on the Internet—this of course means that your Mac friends need to switch their displays to 2.2 gamma when perusing your 2.2-savvy work. Mac-using photographer Gary Ballard maintains a handy demonstration of this phenomenon here.
Labs and Internet-based services using the RA-4 wet process, such as in a Fuji Frontier minilab, almost universally expect you to use a 2.2 gamma in the sRGB IEC1966-2.1 color space. That's true for services such as Pictage, Smugmug, and Shutterfly.
Well, the D50 white point was all the rage among pre-press professionals 10 years ago, and you'd even find talk of D50 in advertising materials. Not so much anymore. D50 comes from a time when the dominant method of photo processing still involved paper, light tables, and viewing lamps. Now the emphasis on digital editing and Internet publishing makes the D65 native white point of modern displays a dominant factor.
The difference between D50 and D65 may still be automatically worked out "under the hood" without your awareness, using a technique known as "chromatic adaptation." That's why D65 is recommended now, unless you are a highly trained expert user.
Choosing a colorspace
In case you're wondering, this is where Aperture settings enter the picture. But before you make settings relative to colorspace in Aperture, you need to decide what colorspace is right for you.
A colorspace is a subset of the gamut of visible color in which available technology allows you to work. Cameras and printers can't reproduce all visible colors, but some do more than others. High-end ink jet printers, for example, can print more colors than the RA-4 wet process can produce. A professional DSLR in RAW mode will capture more color than a point-and-shoot that's capturing straight to JPEG. Again, the point is to do your editing in a colorspace that approximates the output.
Printers using RA-4 will almost always advise working in sRGB IEC61966-2.1, which is also the preferred colorspace for the Internet. For offset printing or high-end ink jet, you'd likely be advised to use a wide gamut colorspace such as Adobe 1998. In all cases, seek the advice of your printing service or printer documentation.
Setting your colorspace in Aperture
In contrast with Adobe Photoshop, you don't have to set your "workspace." Instead, Aperture will always work in a wide gamut, except for when you apply Onscreen Proofing, which shows you how your work should look in final output. When you know your project is bound primarily for one medium, such as RA-4, it's a good idea to leave Onscreen Proofing on all the time while editing, which would give you the equivalent effect of setting your workspace.
After you're done editing your project, set the Export Presets to match the ColorSync profile that you use for Onscreen Proofing.
To make your color settings, using RA-4 as the example output, you would do this:
- From the View menu, choose Proofing Profile > sRGB IEC61966-2.1.
- Look in the View menu again. Notice that there's now a checkmark next to Onscreen Proofing, which only appears after making your initial profile selection. From now on, you can turn it on/off by selecting this menu command or using the Shift-Option-P keyboard shortcut.
- From the Aperture menu, choose Presets > Image Export.
- In the Export Presets dialog, locate the ColorSync Profile pop-up menu, and choose sRGB IEC61966-2.1.
- Click OK.
That's it. You only have to make two settings. If you do your own printing, you can also experiment with the Gamma Adjust slider in the Export Presets to see what looks best with your printer. For a printer-specific discussion where you can learn more about printer setup and print presets, please see Aperture: Optimizing for your printer.