Configuring Photoshop

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Adobe Photoshop is where you perform most, if not all, image color manipulation, including correction, separation, printing, and proofing. Adobe has fine-tuned the color management implementation in Photoshop over the years, and although the latest version, CS2, provides comprhensive color management features, they can be extremely confusing and complicated to use.

Note

Three exercises follow in this section because the configuration of Photoshop's color settings is one of the most important elements of effective color management, it's very important to work through each of the three exercises.


You must first confirm the settings in the Color Settings dialog box and then further customize Photoshop's color management preferences so that the application understands how you want to handle color data.

Exploring Photoshop's Color Settings

Tip

The color management settings for Photoshop versions 7, CS, and CS2 are very similar. If you are using version 7 or CS, you can use the following exercise to configure the options in the Color Settings dialog box.


Photoshop centralizes all of its color management preferences in the Color Settings dialog box. These settings control how the program handles color data and interacts with other color management systems and devices, so it's extremely important to configure these settings correctly for your production requirements.

1.

Launch Adobe Photoshop and choose Edit > Color Settings.


Figure 5.1.


2.

The Color Settings dialog box appears. Click the More Options button.

Tip

In Photoshop 7 and CS, this option is called Advanced Settings.


Figure 5.2.


The Color Settings dialog box lets you select from a set of predefined color management options or customize settings for your particular workflow. The More Options button enables an advanced mode that provides additional options for professional color management settings.


Figure 5.3.


3.

Move your cursor over the various drop-down menus and options in the Color Settings dialog box. Notice that Photoshop displays context-sensitive explanations of each option in the Description field at the bottom of the dialog box. These will help you decide which options are best for your workflow.

4.

Click and hold the Settings drop-down menu.


Figure 5.4.


The Settings menu displays the various predefined color management settings for common workflows that are built into Photoshop. When you choose one of these presets, the Working Spaces (RGB, CMYK, Gray space, and Spot color profiles), Color Management Policies (color-conversion options), and other options in the Color Settings dialog box change accordingly.

Most of the presets are designed for the prepress workflows of various geographic regions and use the appropriate profiles for those printing processes. For example, selecting Japan Prepress Defaults automatically selects a CMYK profile for typical Japanese printing processes. We'll get into the specifics of configuring these settings in a few steps, but let's first explore some of the presets.

5.

Choose Settings > Color Management Off.


Figure 5.5.


The Color Management Off setting is a bit misleading, as you can't actually turn off color management in Photoshop. This setting tells Photoshop to function like an application that does not support color management. Photoshop then ignores embedded profiles and does not embed profiles when images are saved. This setting essentially assumes that every image uses the same working space as the one set in the Working Spaces settings. The Color Management Off setting is really appropriate only for images that will be used in video or in presentations such as Microsoft PowerPoint.

6.

Choose Settings > Web Graphics Defaults.


Figure 5.6.


Web Graphics Defaults is essentially the same as Color Management Off, except that sRGB is selected as the RGB working space. sRGB is a display profile that, like Adobe RGB (1998), can be used as an RGB working-space profile. Microsoft and HP, its creators, based sRGB on what those companies believed was the average PC's display gamut, a relatively small color space. Small color spaces do not make good working spaces.

Tip

If you'd like to interactively see the effects of these settings, click the Cancel button, open an image in Photoshop, and then return to the Color Settings dialog box. Then check the Preview box under the Save button. When the Preview box is checked, Photoshop shows the effect of each setting on the open image file.


These presets provide a good starting point for color-managed workflows, but customizing them for your particular environment will provide maximum benefit.

Customizing Color Management Presets

Let's customize the North American General Purpose Defaults option to learn about all of the specific options and how to choose what's best for you.

1.

In the Working Spaces section of the Color Settings dialog box, choose RGB > Adobe RGB (1998).


Figure 5.7.


Notice that the Settings drop-down menu changes to Custom.

This is a good time to explore the concept of working spaces. The basic color management premise in Photoshop is that each open file can be in a different working space. A working space is the color space in which you edit the file, and it can be different from the original color space of the file, which is called the document color space. Adobe has also separated the document working space from the display space, which means that the color you see on the screen does not depend on the display profile.

Working spaces are based either on color-space profiles such as Adobe RGB or on device profiles. Color space profiles are device independent, which means that they are not representative of any specific device. This makes them a good choice for working spaces. A device profile is meant specifically for the device on which it is based. Using a device profile as a working space essentially means that you are restricting your working space to the colors that can be reproduced by the device upon which the profile is based.

When you select working-space profiles in the Color Settings dialog box, you are telling Photoshop which working space to use when opening an image without an embedded profile, as well as which profile to use when performing a color-mode change (for example, from RGB to CMYK).

The working space is also used when displaying an image on the screen. Photoshop determines the display profile from the Windows Display Properties. When the image is displayed on the screen, Photoshop converts the color data from the working space to the display profile to ensure that what you are seeing is accurate. Photoshop does not actually change the data in the file.

When choosing an RGB working-space profile, you want to select a space larger than the gamut of your devices but not too large. When you edit images, you have a limited number of color values to work with. If you select a space that is too large, the distance between values may be too far, leading to banding or other distortions in the displayed images.

Photoshop provides several RGB working space options. Among them are the following:

  • Monitor RGB [name of display profile] uses the display profile as your RGB working space. This is the preferred option for working with images for the Internet and is essentially the same as working without color management.

  • Adobe RGB (1998), which we have selected, is a working space developed by Adobe. It is designed to provide the best working space for print production. The gamuts of most imaging devices, including CMYK printing processes, fit into the Adobe RGB(1998) gamut.

    Note

    When the Fewer Options mode is selected, Photoshop displays RGB working spaces and the current display profile. When the More Options mode is selected, Photoshop lists all of the installed profiles on your computer, both device and working space, in the working spaces menus. It also provides a Custom RGB option that lets you create your own RGB working space, which you can then save and load using the appropriate commands.

  • Apple RGB is designed to emulate the way that Photoshop 4.0 and earlier versions handle color. The only reason to use this working space is to try to match the way an image looked under one of these older versions of Photoshop.

  • ColorMatch RGB is based on the color space of the older Radius PressView monitors. Unless you are using a PressView monitor or working with images tagged with a PressView profile, there is no compelling reason to use this as your working space.

  • sRGB is designed to represent the average PC monitor, and while it is suitable for Web graphics, it is not recommended for print production.

2.

In the CMYK field just below RGB, choose U.S. Web Coated (SWOP) v2.


Figure 5.8.


CMYK working spaces are essentially printing processes made of ink-and-paper combinations, dot-gain settings, and separation options such as ink limits.

If you have a custom press profile, you would select it as your CMYK working space. When you perform a mode change to or from CMYK, Photoshop will use the CMYK working-space profile for the conversion. It will also use the CMYK working-space profile when you open a CMYK image that lacks an embedded profile.

If you need to convert images to CMYK but do not have a custom press profile, and one is not available from your printer, select one of the profiles provided by Adobe, basing your choice on the type of printing process and paper that will be used, such as U.S. Web Coated (SWOP) v2.

As with RGB working spaces, Photoshop provides the ability to create custom CMYK working-space profiles. This is useful if your print provider does not have a profile but can tell you what separation settings to use when converting your images to CMYK.

3.

In the Gray field, choose Gray Gamma 2.2.


Figure 5.9.


The Gray working space provides a default setting for grayscale images. The setting Gray Gamma 2.2 uses the grayscale equivalent of the default grayscale gamma of Windows computers. (Remember that the gamma of a monitor defines the overall contrast of midtones.) Alternatively, you can define the Gray working space in terms of dot gain. If you want to do so, check with your print provider for the appropriate selection.

Note

The Spot working space menu provides a setting for spot colors, such as PANTONE colors, that may be used in the printing process. Color management for spot colors is covered in detail in Chapter 7, so we will leave this setting unchanged for now.

4.

In the Color Management Policies section, make sure Preserve Embedded Profiles is chosen for all three fields: RGB, CMYK, and Gray.


Figure 5.10.


Color Management Policies determines how Photoshop handles images whose document spaces differ from the working spaces we just set. Two types of exceptions can occur: profile mismatches and missing profiles.

When an image contains an embedded profile different from the current working space, there is a profile mismatch; when an image lacks an embedded profile altogether, there is a missing profile. You can instruct Photoshop to respond to these exceptions by choosing one of the following three options for each of the fields in this section of the dialog box:

  • Off tells Photoshop to disregard embedded profile mismatches and to use the Working Spaces setting. For images without embedded profiles, the document will remain untagged.

  • Preserve Embedded Profiles uses the embedded profile as the working space. This is the preferred option, and we have chosen it.

  • Convert to Working RGB, Convert to Working CMYK, or Convert to Working Gray converts all images from the embedded profile to the profile chosen in the Working Spaces section of the Color Settings dialog box.

Note

Preserve Embedded Profiles is also already chosen in the Color Management Policies' RGB drop-down menus, as part of the North American General Defaults preset, which we are editing. We will leave those options as set.

These actions work in conjunction with an additional set of options: the Profile Mismatches and Missing Profiles check boxes.

5.

Confirm that the Ask When Opening and Ask When Pasting options are selected for Profile Mismatches, and that the Ask When Opening option is selected for Missing Profiles.


Figure 5.11.


When enabled, these settings tell Photoshop to ask you if you want to override the default action each time a profile mismatch or missing profile is encountered, essentially ignoring the policy setting. When these settings are disabled, Photoshop warns you that it has encountered a profile mismatch or missing profile, but it lets you perform only the action set in the policy.

With these boxes checked and the RGB, CMYK, and Gray policies set to Preserve Embedded Profiles, Photoshop will do the following:

  • Tag new documents created in Photoshop with the default working-space profile.

  • Open images tagged with the working-space profile without any changes.

  • Display an Embedded Profile Mismatch dialog box when you open an image tagged with a profile other than the working-space profile. This dialog box will ask you how to handle the data. The Use the Embedded Profile option will be selected by default (as a result of our policy settings). When you encounter this dialog box, click OK to open the document and edit the image in the document space unless the document space is a scanner or camera profile. Those color spaces are typically too small to edit in.


    Figure 5.12.


  • Edit images without a profile in the specified Photoshop working space, but without tagging the image with a profile.

Essentially, you should always keep images in their document spaces for editing. So if the file is tagged with a profile, use it and do not convert to a working-space profile. Rarely is there an advantage to converting a file to another working space. If the working space is larger than the document space, nothing is gained you usually don't get more color data. However, if the working space is smaller than the document space, you typically do lose data.

There are only a couple of situations in which you will want to convert an image to a different working space. First, if the image does not have an embedded profile and you do not know its source, then you should convert the image to the working-space profile. Second, if you are compositing multiple images together, you want all of your images to be in the same working space, and you may need to convert some images to achieve this.

You'll see how these policy settings work later in the chapter, when we open images from different sources. Right now, let's look at the additional options enabled in the Advanced Mode of the Color Settings dialog box.

Configuring Other Advanced Settings

As you saw in the previous exercise, the Advanced Mode of the Color Settings dialog box lets you select any profile as a working space as long as the profile is in the same color space as the working space. In addition, Advanced Mode enables two other sets of options: Conversion Options and Advanced Controls. The following exercise helps you explore what these options do. However, unless you specifically need to change them, you should leave these options set to the default.

1.

In the Conversion Options area, in the Engine field, choose Adobe (ACE).


Figure 5.13.


Photoshop lets you choose from at least two color matching methods (CMMs), which Adobe calls conversion engines, to convert colors between different profiles. They are as follows:

  • Adobe (ACE), or Adobe Color Engine, is Adobe's own CMM. It is built into all Adobe professional design applications but is unavailable to non-Adobe applications.

  • Microsoft ICM tells Photoshop to use the CMM built into Windows XP.

If you work in an environment that uses a mix of Adobe and non-Adobe applications, the Microsoft ICM conversion option will ensure consistent results across applications.

If you work in an all-Adobe but cross-platform environment, choose Adobe (ACE) to ensure consistency across platforms. If you work in an all-Adobe, all-Windows environment, you can choose either Adobe ACE or Microsoft ICM CMM, as you will have access to both conversion options in all of the professional Adobe products you use.

2.

In the Intent field, make sure that Relative Colorimetric is selected from the drop-down menu.


Figure 5.14.


As explained in Chapter 1, the rendering intent controls the way that color is mapped between the gamuts of two profiles. This menu lets you choose which rendering intent Photoshop uses to convert an image upon opening, to make color-mode changes, and to display color values on the Info palette.

Note

You'll learn how to check an image for out-of-gamut colors in Chapter 6.

Relative Colorimetric compares the highlight of the source color space to that of the destination color space and shifts out-of-gamut colors to the closest reproducible color in the destination color space. Relative Colorimetric is a good choice when most of the colors are in gamut. For an image that contains many out-of-gamut colors,Perceptual is a good choice, because it preserves the overall relationship between colors.

3.

Make sure that the Use Black Point Compensation and Use Dither(8-bit/ channel images) options are both selected.


Figure 5.15.


Use Black Point Compensation compensates for differences in the black points of two profiles. Although the effect is difficult to detect, it's a good idea to check this option.

The Use Dither option can reduce banding that may appear when an image is converted between two color spaces.

4.

In the Advanced Controls area, make sure the Desaturate Monitor Colors By and Blend RGB Colors Using Gamma options are not selected.


Figure 5.16.


Desaturate Monitor Colors is designed to accommodate very large working spaces, and checking it can lead to onscreen colors that do not match printed colors. Blend RGB Colors lets you choose a gamma when overlaying two colors. When this option is disabled, RGB colors are blended in the document color space, which is how most applications perform this task.

5.

Confirm the settings in your Color Settings dialog box.


Figure 5.17.


Now that you have customized Photoshop's Color Settings for your workflow and production environment, you can save the settings so that they can be easily restored if they are ever changed, and so that you can share them with other users and among other Adobe applications.

6.

Click the Save button. Photoshop displays the Save dialog box.


Figure 5.18.


7.

Enter an intuitive filename in the File Name field and click Save.


Figure 5.19.


8.

When the Color Settings Comment dialog box appears, enter a description for your Color Settings file, if you like; then click OK.


Figure 5.20.


Congratulations! You have now configured Photoshop to work in a color- managed workflow. Photoshop will use these custom color settings to determine how to open and display images, ensuring that images are reproduced as accurately as possible. In addition, because Adobe Creative Suite applications such as InDesign, Illustrator, and Acrobat all use the same Color Settings preferences, you can load your saved settings file into each of those applications, an exercise we'll perform in Chapter 7. This will ensure consistency across all of those applications without your having to manually re-create the settings.

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    Microsoft Windows XP Color Management
    Microsoft Windows XP Color Management
    ISBN: 0321334272
    EAN: 2147483647
    Year: 2005
    Pages: 103

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