4.1. Establishing a Working Color Space
4.1.1. Which One Do I Pick?
Here are five scenarios for choosing different working space setups in Photoshop:
When choosing your working color space, it is best to consider your primary output. For instance, if your work is usually printed in-house on an ink-jet printer, Adobe RGB (1998) or ProPhoto RGB is a good choice. If you send files to a photographic lab, check with the lab to see if it has color space requirements, and if it does, use that color space as your working space. Note that you don't have to use the same space that the lab does; doing so can help in production, but it isn't completely necessary.
If you have an ink-jet workflow in addition to your photographic lab workflow, one option is to use Adobe RGB (1998) as your working space and convert to the lab's space when you're ready to send the file. At the end of this chapter, I'll show you how to establish an action to convert to sRGB and save in a folder ready for the lab.
4.1.2. Setting Your Working Color Space
You can set your working color space in Photoshop under Edit Color Settings. This opens the Color Settings screen where you can select the RGB working space that is suited for your particular workflow. Photoshop is quite capable of managing any color space a file is tagged with, and even more impressive, Photoshop can handle multiple color spaces (from multiple open files) all at the same time.
At the top of the Color Settings window is a drop-down menu for choosing a set of overall Settings. (In this example, it's set to the default: North America General Purpose 2.) This setting gives you specific working spaces for each color model; in this case, sRGB IEC61966-2.1 is the default RGB Working Color space along with U.S. Web Coated SWOP v2 for CMYK and Dot Gain 20% for Gray and Spot.
You can set any of the items in the Working Spaces box independently. For RGB, there are four primary choices: Adobe RGB, Apple RGB, ColorMatch RGB, and sRGB. My personal choice for my working color space is Adobe RGB because my workflow includes processing images for ink-jet printing, photographic labs, and prepress, and this working space covers most of these output gamuts during conversion.
In the next box are the Color Management Policies options. The default setting for each color mode is to Preserve Embedded Profiles, which is the best choice when you work with images that have various embedded profiles. From each of these drop-down menus, you can also choose "Convert to Working RGB," which is a good choice when you have a closed loop workflow (such as shooting with one camera and printing to one printer) or if you are processing images for use on the Internet. "Convert to Working" RGB is designed to automatically convert files to your chosen working space according to the model (i.e., RGB, CMYK, Gray) when you open them in Photoshop. The Off option will pass the files straight through, but Photoshop may display a message when you open a file to remind you that the tagged file is different from your chosen RGB working space.
126.96.36.199. Mismatch warning
Checking the options for when Photoshop should ask you about Profile Mismatches and Missing Profiles will cause Photoshop to display a warning when you open images that are not in your working RGB color space. The warning will show you which profile is embedded and options to manage the document's profile. If a file has a color space home, keep it by selecting "Use the embedded profile"; that is the best policy unless the embedded profile is from an input profile such as a scanner or digital camera. In that case, choosing "Convert document's colors to the working space" will convert the color space into your color space workflow.
In a color-managed workflow, when a file has no embedded profile, you certainly want to assign one to it. Photoshop offers two choices for assigning a profile, and which one you choose depends on the source of the file. In most cases, the second choice, "Assign working RGB," is best. If you have a scanning or digital camera workflow but the device does not apply an input profile, choosing an "Assign profile" option from the pull-down menu allows you to select the scanner or digital camera profile that works best. You also have the option of then converting to your working RGB, which is the best choice in most cases.
Photoshop also offers one of these options: "Leave as is (don't color manage)" or "Discard the embedded profile (don't color manage)." These options are handy when you must process images with no profile embedded. If you have a file with a tagged profile but your lab requests an untagged image, from the main menu in Photoshop you can choose File Save As.... In the Save As dialog box, youll find an option at the bottom to uncheck Embed Color Profile. This will strip the embedded profile for your lab's requirements.
188.8.131.52. Advanced options
Click on the button to expand the Color Settings window. You now have Conversion Options, Advanced Controls, and if you select the RGB drop-down menu in Working Spaces, you'll notice a gazillion choices for a working space. (Here you can choose ProPhoto RGB as your working space, but select this profile only if you are an advanced user. )
In the Conversion Options box, you can set a couple of the items we learned about in Chapter 2. The default engine, Adobe (ACE), works very well when converting profiles in Photoshop. (The engine is the Color Management Module that we discussed in Chapter 2.) Adobe (ACE) is the best choice unless you have a specific reason for using a different engine. What you select for the other options will depend on your operating system and any other software you may have installed. Here you can also set your Rendering Intents (as we discussed in Chapter 2). Relative Colorimetric and Perceptual are the two most commonly used rendering intents. In a basic workflow, consider Relative Colorimetric for ink-jet printing and Perceptual for photographic paper printing, such as your lab might use.
Checking the Use Black Point Compensation options will compensate the black point of your image according to your (properly calibrated) monitor's profile. When the known values of a black point are displayed on your monitor, this option attempts to replicate this known black point. Using Dither (8 bit/channel images) will ease the transition between profiles where banding may become apparent. Both options should be checked.
In the Advanced Controls, you will find the option to Desaturate Monitor Colors by a specific percentage. This option is rarely used today, even though it does offer compensation for overly saturated monitors once a consistent workflow has been established. The Blend RGB Colors Using Gamma option is designed to dither your brush edge with certain color blendings, which may result in fewer edge artifacts.
In the Description box at the bottom, you'll find a wonderful amount of information regarding anything that your cursor hovers over. Position your cursor over any part of the Color Settings window to read a brief description of a profile or option.
4.1.3. Saving Your Color Settings
Whether you choose customized or established settings, be sure to save them by clicking the Save button. A dialog box will appear in which you can name your settings something useful; I've named mine TMAX3. When you save your color settings, a Color Settings Comment window will appear, so you can type in any specific instructions or comments regarding your color settings.
Saving these settings will create a .csf file in the Applications Support folder in your system. You can send this file other workstations. From the Color Settings window, select Load to load the same settings on the new workstation without having to match the settings manually.
4.1.4. Assigning Versus Converting Profiles
In the course of a normal workflow, assigning profiles isn't a usual procedure. However, as this illustration shows, assigning a different color space to an image can contract or expand the appearance of the color gamut and gamma, depending on the original color space (Adobe RGB (1998) in this example).
It's important to understand the distinction between assigning and converting profiles. Converting profiles will maintain the same color appearance while actually changing the numeric pixel data. Assigning profiles will not change the numeric pixel data but can indeed change the color appearance.
Assigning profiles is most successful when assigning an input profile from the device in which the image was originally created, such as assigning a scanner profile after the scan, and then converting it to a working space. (This is, however, done mostly within the scanner software so it remains seamless.)
To assign a profile from the main menu in Photoshop, select Edit Assign Profile. In the Assign Profile dialog, "Dont Color Manage This Document" allows you to untag a color space via the selection. Using the second choice, you can apply your working color space. The third choice gives you a drop-down menu that shows the profiles available in your system. With Preview checked, you can easily see how assigning a different profile will affect the appearance, but the numeric pixel data will remain the same. Think of this as placing a filter of sorts over the image.
Converting profiles does indeed change the pixel data. However, because Photoshop automatically takes advantage of the CMS (as explained in Chapter 2), when you choose "Convert to Profile" in Photoshop, you will see very little (if any) changes in the color appearance because Photoshop is considering the color space of the file and the color space it is converting to before displaying this information through your monitor's calibrated profile. In this way, Photoshop automatically emulates what is known as a "proof view."
And speaking of proof view, you can proof your colors by choosing View Proof Setup Custom and then selecting the ICC profile that you will be printing to. Photoshop will display your image as if it had been converted to that profile. Using Proof Setup will emulate out-of-gamut colors and tones, allowing you to make corrections and adjustments in the files current space if needed. Designed primarily to help view out-of-gamut color when converting from RGB to CMYK, this feature works with any output ICC profile.