Image editing can be a complex task at times, but for many people, editing pales in comparison to what is involved with getting a good print. Along with choosing the right paper, printer profile, and printer settings to get the best possible image, you also have to deal with rendering intents.
What exactly is a rendering intent? In basic terms, it controls how the colors in your source image (the digital file you have created) are mapped (translated) to colors that your printer can reproduce. Because the projected light of your display is different from the reflected light of prints, you will never see an exact match between the your display and your printer. But with the proper rendering intent, you can optimize your printing process to get colors in your print that are as close as possible to the colors you approved the display.
In Photoshop you can choose from four rendering intent options:
- Relative Colorimetric
- Absolute Colorimetric
Of these settings, only Relative Colorimetric and Perceptual are appropriate for photo printing. Both Lightroom and Aperture recognize this and offer just these two choices when printing. The choice you make between the two depends on how you want colors to be remapped in your image.
Color rendering is used only when your image contains colors that your printer cannot be reproduce.(The range of colors that a device can reproduce is known as its gamut.) So if your image contains colors that are outside of your printer’s gamut, the printer needs to substitute those colors with color that it can handle. How those colors are changed is where relative and perceptual come into play.
Relative Colorimetric is the best choice when color accuracy is the highest priority. It works best when the range of color in your image is narrower, and the bulk of the colors are already reproducible by your printer. With relative colorimetric, only those colors that cannot be reproduced will be changed. This works well in many cases. But it can lead to problems in areas such as the sky in which you might have a wide range of very subtle tone differences. When a color is remapped into the space the printer can reproduce you might see banding in areas such as skies because the subtle tones that are outside of your printer’s gamut are now printing with the same values as the ones that were within the gamut that did not change.
Perceptual shifts all colors in your image an equal amount in order to get all of the colors within your printer’s gamut. At first, this might sound like the perfect solution, because if everything shifts equally you shouldn’t expect to see any changes. But when the perceptual color rendering compresses all of the colors to make this work, you might see some reduced saturation in some cases. By itself, you might not notice this reduced saturation at all. But when you compare your print to a monitor, the difference might be more obvious than the print you output with the relative colorimetric setting.
So, which should you choose? Like most things, the only honest answer is “it depends”. It depends on whether your image has a wide range of color, or if it has highly saturated tones.
Luckily, you can preview the effects of these intents prior to committing them to paper. In the images below, I’ve selected relative (figure 1) and perceptual (figure 2) rendering intents in Aperture. The differences are most apparent in the sky where the perceptual intent is reducing the blues. On the opposite side though, you can see that relative intent is affecting the building and foreground slightly with less color in these areas. In this particular image, I would choose to print with perceptual since it gives me a closer match to the editing I have done.