White point is how the color white is produced or defined on a device or media. The industry standard for white point is D50 (5000K), but others also use D65 (6500K) (Figure 2). Either white point setting is fine if there is not an adjacent viewing booth because the eye will adjust to the white point. However, if you are soft proofing and there is an adjacent viewing booth, then white point will be more important and must be adjusted to D50.
Gamma refers to midtone, and many arguments have been made as to whether a setting of 1.8 or 2.2 is correct. The bottom line is this: Gamma is not a factor since 1.8 and 2.2 will look the same (because the profile actually compensates for the gamma) after profiling when using any software application that is ICC-compatible (i.e. InDesign, Photoshop, Illustrator, QuarkXPress, etc.). However, the desktop and non-compatible ICC software (such as Microsoft Office applications) will look lighter with a gamma of 1.8 and darker with 2.2.
Brightness and contrast will differ based on the display you’re using. With Apple displays, there isn’t much to adjust. The backlight should be adjusted to maximum brightness to render the best shadow detail. For brightness and contrast, there is nothing to adjust. Within the profiling software, set white point to D50 or leave “native” if no viewing booth is adjacent and set the gamma to 2.2.
With non-Apple displays, you typically have more settings, which is not necessarily a good thing as the controls may work differently based on the manufacturer. The display backlight control works like a dimmer, and the brightness control adjusts the white point brightness. Contrast controls white-to-black contrast. LCD contrast control is a little more confusing and may react differently on different LCD displays. Unfortunately, there is no common interpretation or control of contrast among manufacturers. If you don’t know how the brightness and contrast controls work, open up a grayscale and make adjustments to see exactly how your display reacts.
The next step is to use the profiling software to create and install the profile. A workstation has one system profile that is used by all applications. Most profiling software will make the most recent profile that was created the system profile. ICC compatible software (Adobe CS, QuarkXPress, etc.) automatically recognizes the system profile while non-ICC compatible software will ignore it.
Finally, the profile must be tested to make sure it is working properly and giving the intended results. First, open a grayscale (you can create one in Photoshop or download one from www.hutchcolor.com). View the grayscale in Photoshop and check for neutrality throughout the grayscale, banding, clipping (loss of detail) in the highlights, or plugging (loss of detail) in the shadows.
Next, test the accuracy of the profile by comparing an image opened in Photoshop with a hard proof or printed sheet. Select an image that is representative of the type of work that you do. An image with fleshtones, neutral grays, and saturated reds, greens, and blues are always a good choice. Follow the steps below to display an accurate soft proof in Photoshop (Figure 3):
1. Select View > Proof Setup > Custom
2. Assign the output profile (this is the device that you want to simulate) to image in Photoshop and Simulate Paper Color.
3. Select Simulate Paper Color. (In theory, turning on Simulate Paper Color should give you the most accurate soft proof possible and uses the paper color in the profile if it is available. In practice, the most obvious effect of selecting Simulate Paper Color isn't that it simulates the color of the paper, but rather that you see the compressed dynamic range of print.)
3. Adjust dimmer on the viewing booth until brightness of substrate in booth matches brightness of the “paper” in Photoshop.
4. Evaluate color visually.
One of the most common questions when it comes to color management and soft proofing is, “how often should I re-profile?” The answer to this question is this: Profile only as often as necessary. Ideally, only re-profile when one of the following occurs: