The Critically Important Color and Gamma Calibration Article
This article will explain how to understand and work with Photoshop's Color Management System (CMS), including how to create a custom profile, how to create an ICC profile for a monitor, how to set Photoshop's CMS defaults, how to use the Color Settings dialog box, and much more. It is excerpted from Inside Photoshop CS, by Gary D. Bouton. (Sams, 2004, ISBN: 0672326442).
The Critically Important Color and Gamma Calibration Article - Install the Latest Drivers for Your Equipment (Page 6 of 16 )
Before you begin to set up your system and Photoshop to use color management, make sure that you have installed all the latest drivers for your equipment. Monitor, video card, scanner, and printer manufacturers often update their drivers to fix bugs and to add or update the ICC profiles they have created for their products. These default manufacturer profiles are what you'll use if you don't create custom-made profiles for your equipment. In addition, they are often used by products that profile things, including Adobe Gamma, as a basis for the custom profile. So, fire up your Internet browser or give customer service at each place a call, and get the newest drivers the equipment manufacturers have to offer. Follow their instructions for installing the drivers on your computer.
Creating an ICC Profile for a Monitor
Okay—gamma, brightness/contrast, and other parameters lie ahead of us. Follow these steps to create an ICC profile for your monitor, using Adobe Gamma:
Profiling Your Monitor
If you haven't done so already, go to the monitor manufacturer's Web site and download the most recent driver, and then follow the instructions there to install it for your monitor.
Insider - By installing the latest drivers, you ensure that the Adobe Gamma will base its work on the most accurate information available about your monitor.
With Photoshop and other applications closed, open the Control Panel(s) (folder), and double-click the Adobe Gamma icon.
The Adobe Gamma Control Panel opens. You can choose to work with a single dialog box that has a number of different tasks, or use a step-by-step method that involves a Windows Wizard.
Click to set the Control Panel option, and then click Next. We'll show you how the single dialog box version (shown in Figure 2.3) of this application works, but you're free to switch to the step-by-step method at any time by clicking the Wizard button.
In the Description field, you should see one or more profiles listed for your monitor. These profiles are already installed on your system and assigned to your monitor. If there are two, one was probably installed when you installed your operating system, and the other is the one you just downloaded and installed from the monitor manufacturer. Unless you told the install program differently, the last installed profile is the one currently in use.
Highlight the profile you just installed in step 1, and type a meaningful name, like Downloaded 11-14-03, to indicate that you downloaded it on November 14, 2003. This will make it easier to pick the profile from a list (if you choose to use this profile at a later date).
Adobe Gamma will base the new profile being created on the highlighted profile in the Description field.
Figure 2.3 If you want to walk through the process of using the Adobe Gamma Control Panel screen by screen, click the Wizard button.
Click the Load button if you want to base the new profile on a profile other than the one currently in the field.
Using the controls on your monitor, increase the Contrast to 100%, or set it as high as the control will go. With your eye on the Brightness and Contrast section of the Adobe Gamma Control Panel, use the monitor's brightness control to adjust brightness up or down until the gray squares in the gray-and-black checkerboard strip are almost black (see Figure 2.4). The goal is to end up with an almost black-and-black checkerboard strip above a crisp, bright white strip. If the white gets dirty, be sure to increase the brightness. If your monitor has onscreen controls, fiddle with them the same as you would do with on-monitor knobs.
Warning -Changes to contrast and brightness will affect profiles
If you change the monitor's contrast and brightness settings later in the profile-making process, or at any time in the future, the profile will no longer be accurate and you will have to create a new profile. If your monitor has external knobs that adjust brightness and contrast, you should use duct tape—or stronger—to tape them down so they can't be changed by accident.
Figure 2.4 Use your monitor's brightness and contrast knobs or onscreen controls to make the gray squares in the Adobe Gamma Control Panel almost black.
Change the Phosphors setting only if you are absolutely certain that what is shown is wrong. If you are certain it is wrong, but you don't know what the right setting is, the best guess would be Trinitron.
Adobe Gamma sets the Phosphors properties based on information from the manufacturer's profile. If you installed the latest driver and profile from your monitor's manufacturer, you probably won't have to make any changes with the Phosphors drop-down list. For many users, the setting will be Custom; you should leave it alone and move on to the fun control: Gamma.
Make sure that the View Single Gamma Only option is checked. Then lean back and squint, and drag the slider to the left or to the right until the solid tone in the center has the same apparent tone as the stripes outside the box.
You just defined gamma by using a composite control that applied the same gamma setting to each of the three RGB channels. This "one-gamma-setting-fits-all-channels" method works just fine for most people. However, if you want greater control or if you think that your monitor's RGB channels are a little out of sync with each other, clear the View Single Gamma Only option and, one by one, drag the slider under each box until the center box fades into the striped frame around it. Then move on to the next step.
Note -Older Windows operating systems
If you are using Windows NT 4 or Windows 95 with certain video cards, you will not have the option of choosing a setting from the Desired drop-down list, as shown in the next step. This is a limitation imposed by the operating system, not by Adobe Gamma. Some Windows 95 users and all Windows 98, ME, 2000, and XP users will have the option available to them and should follow the advice in the next step.
Choose Windows Default, Macintosh Default, or Custom from the Desired drop-down list. These are the options as of this writing; however, as we mentioned earlier, Adobe has no plans to implement Adobe Gamma on the Macintosh platform. I chose Windows Default (see Figure 2.5) because I'm working on a Windows computer. If you choose Custom, you will need to enter a value in the field next to the drop-down. We don't recommend choosing a custom setting unless you are very experienced in color management and have a very compelling reason to do so.
Figure 2.5 Choose from the (Gamma) Desired drop-down list. Your choice should match your operating system.
Insider - In the White Point area of the Adobe Gamma Control dialog box are two drop-down lists. The first refers to the actual hardware setting of your monitor.
Click on the Hardware drop-down list and choose the color temperature your monitor actually uses. Earlier in the chapter, this is the value you set or determined in the "Read Your Monitor Manual" section.
If you were unable to determine the hardware setting, or if your monitor is old and you think it might not be operating as well as it used to, click the Measure button next to the Hardware drop-down list. Follow the onscreen instructions carefully. Removing all ambient light means the room should be dark. You may even want to wait until night to do this if your workspace has windows. Click the center square when you are done. The entry in the Hardware drop-down list will now read Custom.
The Adjusted drop-down box offers the same color temperature choices as the Hardware drop-down list did. Adobe Gamma can override the hardware settings and force the monitor to display other standard white points.
Note -Use consistent lighting
The lighting conditions present when you're calibrating and profiling the monitor should be maintained when you use that profile. If you use other lighting conditions, you should recalibrate and reprofile. In other words, don't calibrate your new computer in the store and expect the profiles to hold true when you get the machine home.
If you ever need to use a nonstandard white point, choose Custom from the list, and enter the values that describe the custom white point.
If your monitor can display the color temperature you want to use, choose Same as Hardware from the Adjusted drop-down list. If your monitor has a fixed color point of 9600K, for example, and you want to use a 5000K white point to more closely mimic paper, choose 5000K from the Adjusted drop-down list, as shown in Figure 2.6.
Click OK, and then in the Save As dialog box, give a descriptive name to your monitor's custom profile. On the Macintosh, the file extension would be .pf; in Windows, it's *.icm.
For example, I'm calling the settings for one of my machines Win XP machine 11-14-03.icm. In this way, I can tell how recently I profiled the monitor.
Click Save, and then click OK in the Gamma Control Panel to finish calibrating and profiling your monitor.
Figure 2.6 Choose a color temperature in keeping with the way you view your final output in Photoshop.
It probably took longer to read how to calibrate and profile your monitor than it took to actually do it! This is a good thing, because if you want to keep your colors consistent, you really should recalibrate and reprofile your monitor at least once a month, even if nothing noticeable has changed in the environment. Recalibrate and reprofile right away if something does change in the environment. Changing a light bulb or repainting the room both qualify as events that should cause you to open Adobe Gamma and run through it one more time.
Now that every color management–aware piece of software on your system has a target profile for your monitor, it will be easier to establish color consistency when you print or do Web work in Photoshop. The next thing to do is to set up a working color space for Photoshop.
Photoshop and the CMS look in specific folders for profiles. The location of the folder that stores profiles depends on the operating system you use. Table 2.2 shows where you should save profiles you've created or obtained if you want to make them available for use.
Table 2.2 Required Locations for ICC Profiles
Installed Location of ICC Profiles
Windows NT version 4
Macintosh OS using ColorSync, earlier than version 2.5
System Folder, Preferences, ColorSync Profiles
Macintosh OS using ColorSync version 2.5 or later
System Folder, ColorSync Profiles
To recap: You've profiled your monitor, and the operating system has assigned that profile to your monitor. Now it is time to open Photoshop and start setting up the rules for the way it should do its part in the color management process.
This chapter is from Inside Photoshop CS, by Gary D. Bouton. (Sams, 2004, ISBN: 0672326442). Check it out at your favorite bookstore today. Buy this book now.