Table of Contents
Table of Contents
Table of Contents
PHOTOSHOP PREFERENCES
Before you start working on your images in Photoshop, you need to configure the behind-the-scenes settings that control how different aspects of the program behave. I like to think of this routine as being similar to picking up a rental car at the airport. There are always a few things—positioning the mirrors, adjusting the seat, finding the headlight switch, checking the gas level, and choosing a decent radio station—that I like to do before I drive out of the parking lot and hit the open road.
Photoshop provides numerous ways for individual users to customize the program. From actions that record commonly performed tasks, to user-defined keyboard shortcuts and saved workspaces, there are different avenues to getting the program set up just the way you like it. The place you should start, however, is with the Preferences settings. On Mac OS X, Preferences are located in the Photoshop menu; on Windows systems, they can be found under the Edit menu. There are a lot of preferences, and many of them are specific to tasks and workflows that are more for graphic design and Web-related fields. So I won't discuss each one in minute detail. Instead, I'll address the most important preferences that pertain to the overall operation of the program in general, and more specifically, to those items that have the most impact on the type of work that digital artists and photographers are likely to do. The following text on preferences and color settings is excerpted with permission from my book, Real World Digital Photography.
General Preferences
- Image Interpolation. Interpolation refers to the method by which new pixels are created or existing pixels are thrown away when an image is sized. Choosing an interpolation method here will affect how interpolation is done in other areas of the program, such as when you scale an image or transform an image element. The change is immediate and does not require a restart of the program. If you are using Photoshop 7 or earlier, you should choose the Bicubic method because that is the most accurate algorithm for photographic images.Photoshop CS has introduced two new interpolation methods: Bicubic Smoother and Bicubic Sharper. For upsampling images (which means making them larger), Bicubic Smoother is almost always the better choice. Bicubic Sharper will often provide the best results for downsampling (or for making an image smaller), although the results can vary from image to image, so the choice is not as clear as Bicubic Smoother is for upsampling. All of the interpolation options are available in the Image Size dialog box (see figure 1.18) and can be chosen for specific images as the need arises. If you choose to scale an image larger or smaller using the Free Transform tool, there is no way to specify an interpolation method. The preference setting is the default, which is why I leave it at Bicubic and adjust the Image Size setting as needed.
Figure 1.18. The image interpolation algorithms are available in the main Photoshop CS Preferences and the Image Size dialog box.
- History States. At the most basic level, the History feature in Photoshop is a super undo command that lets you move backward through the editing steps and undo changes. Photoshop refers to every separate change as a history state, which can be anything from a tonal correction, to a paintbrush stroke, to resizing the image. As you might imagine, this provides great flexibility and insulation from “no way out” mistakes that occur during the editing process. The default number is 20, and the maximum number of history states is a whopping 1,000. Whether you'll actually be able to get by with the maximum amount will depend on a number of factors, including the size of your image, how much RAM you have, and how much free disk space is available for Photoshop to use as a Scratch Disk. Until you get a better idea of how many history states is a good number for you, I suggest beginning with 50.
- Export Clipboard. This setting lets you copy pixels from Photoshop and paste them into another application. Keep in mind, however, that this process can put a large chunk of pixels on the clipboard (the computer's copy buffer) and create a brief lag when you switch to another program. Unless you specifically need to do this, I recommend you leave this preference unchecked. In many cases, what you have copied is too large for the clipboard, and you will see a “clipboard export failed because it is too large to export” warning, which only serves to slow you down as you move between programs. Unchecking this feature still lets you copy and paste within Photoshop itself.
- History Log. New to Photoshop CS, this preference lets you save a record of what you've done to an image. You can choose to save this information to a file's metadata, to a separate text file, or both. The details can be restricted to the following: Sessions Only, which simply records when you open and close a file; Concise, which tracks session info and keeps a record of every step you perform, similar to the record you see in the History palette; and Detailed, which tracks session info similar to the way the Actions palette does it, keeping a surprisingly detailed record of everything you do to an image, including filter and color correction settings. If you want to remember what you have done to an image, the Detailed option can be very useful.
File Handling
- Image Previews. If you want Photoshop to save small versions of the image to be used as icons or preview thumbnails by your computer's operating system, the Image Preview setting is the place to go. Note that this preference has nothing to do with the thumbnail previews generated by the File Browser. If you're generating images for the Web, you usually won't want to save either previews or icons because no one visiting a Web page will see them, so they needlessly increase the file size. If you want to choose on a per-image basis whether these items are generated, select the Ask When Saving option.
- Ignore EXIF sRGB tag. Color tags are used to give meaning to the color numbers in a digital image so that the appearance of an image will be consistent on different color-managed computers. Some digital cameras will automatically tag their images with an sRGB color profile, even if you have specifically chosen Adobe RGB in the camera's setup menu. While the sRGB profile may represent a correct interpretation for the images a camera produces, it is just as likely to be no more than a “default” tag provided by the camera that does not necessarily reflect the best way to interpret the colors in an image. If you determine that another color profile, such as Adobe RGB or ColorMatch RGB, works well with the images from your camera, you can use this preference to have Photoshop ignore the sRGB tag contained in a camera's EXIF data. If you are using Photoshop 7, you can add this functionality to the program by downloading a special Ignore sRGB Profile plug-in from the Adobe Web site (www.adobe.com/products/photoshop).
- Ask Before Saving Layered TIFF Files. In the old days, only Photoshop's native PSD format could save layers. Now the club is not so exclusive, and the TIFF specification has the ability to support layers, too. This is really only an issue if you're using TIFF files in page layout programs. In the past, some layout applications would get downright cranky if they encountered a layered TIFF. Photo graphers and production artists would also use the TIFF format for the flattened images that were placed in the layout program and reserve the PSD format for the work-in-progress layered image. The different file formats were another way to keep it clear that the correct, nonlayered file was placed in the page layout. Although programs like InDesign can handle layered TIFFs and PSDs, many designers and prepress businesses still use flattened TIFF files to minimize workflow confusion. If you want a reminder that you're saving a layered file in TIFF format, turn this option on. I leave it off.
- Enable Large Document Format (.psb). New to Photoshop CS, this preference lets you save very large files (300,000 × 300,000 pixels), which was not possible in earlier versions. The previous 30,000 pixel limit is still the largest size that can be saved using the standard PSD format, but larger files can now be saved as TIFF (up to 4GB) or the new PSB format. This new format and the new image size limits are not backward compatible with earlier versions of Photoshop. The number of people who have a need for such gargantuan files is very small, and I recommend that you leave this preference unselected, simply to protect against accidentally creating a file this big. If you feel compelled to stitch together 97 6-megapixel photos into a single, monumental image, however, this is the preference you need to set to make that possible.
- Maximize PSD File Compatibility. This option has been around in several versions of Photoshop under a variety of names, and it controls whether Photoshop will include a hidden, composite layer along with the regular layers when you save a file. The composite layer is essentially just a single layer that represents what the image would look like with all the visible layers flattened. This preference is primarily for people who need to use their layered PSD files in other applications, which claim to read PSD files but need that composite layer in order to do so. The main problem with this option is that the extra composite layer will make your file size much larger—up to 33 percent larger—than it needs to be. Although this is not much of an issue with small files, it can quickly become a big issue with larger documents. If you're working on your images only in Photoshop, I recommend you leave this preference turned off and save some disk space.
Display and Cursors
- Color Channels in Color. I feel strongly that this preference should be left unchecked. When turned on, it displays the individual color channels with bright-colored overlays to match their names. The channels have names that identify them, and the colored overlays actually make it much harder to evaluate the tonal detail in the channels. You're better off leaving this unchecked and viewing the default grayscale versions of the color channels (figure 1.19). In addition, we'll often use the image channels as a foundation to create an alpha channel, as discussed in Part Three of the book, “Selecting and Preserving Fine Detail.” Being able to inspect the image channels is always the first step in building a good alpha channel.
Figure 1.19. Leave the display of the color channels set to the default grayscale view. The RGB colored overlay makes it hard to evaluate the tonal detail.
- Painting Cursors. This is probably the most important setting on this panel. When you set the painting cursors to Brush Size, you can see a circular cursor that represents the actual size of the brush you're using. If the cursor is the default brush symbol icon, you won't know how large your brush is until after you've painted on the image. The Other Cursors preference lets you choose between standard, which is the tool icon, and a precise crosshair.
Tip
Transparency and Gamut
The fourth preference screen controls how Photoshop displays areas on layers without information and gamut warning color.
- Transparency Settings: Grid Size & Colors. When you have an image element on a separate layer, it can either fill the entire size of the image or occupy only a portion of the image area. If the pixels on the layer do not fill up the full image area, Photoshop uses a checkerboard pattern to represent the transparent pixels that surround it. You'll only see the pattern if you turn off the eye icons in the Layers palette of any underlying layers. If you're new to Photoshop or Photoshop Elements, the checkerboard pattern may be confusing at first. Essentially, the program needs to have something there so that you can see there is nothing there. I have found that the default colors and grid size work fine for most images. Clicking in the colored swatches will take you to the Photoshop Color Picker where you can choose new colors for the grid.
- Gamut Warning. When the Gamut Warning is activated (from the View menu, choose Gamut Warning), Photoshop will place an overlay tone over any colors in the image that are out of gamut for the current CMYK setup specified in the Color Settings dialog box. You can also use it to display the out-of-gamut colors if you have selected an inkjet profile as the current proofing space. The default battleship gray at 100% works pretty well for most images…unless you have a photo of a battleship on a foggy day, in which case lime green or shocking magenta might be a better choice.
Units and Rulers
As its names implies, the fifth preference screen controls how Photoshop measures image and document information.
- Units. I prefer to change the ruler units in the main Photoshop interface, either by (Control-clicking) [right-clicking] inside the rulers, or by accessing the units in the XY section of the Info palette (see figure 1.20). If you'll be printing most of your images, use the measurement system you are most familiar with. If you were raised in the United States, that's likely to be inches; if you're from almost anyplace else in the world, you might be more comfortable with centimeters. If you need to prepare images for the Web, pixels are the best choice.
Figure 1.20. Changing units of measurement via the Info palette is faster than changing the preference setting.
- Column Size. If you are doing any work on a publication that uses columns for arranging text on a page, such as a newspaper, specifying the exact size of your columns here lets you resize images or create new files, based on the column width used in your publication. If you want to resize a photo so that it is two columns wide, for instance, the column size preference tells Photoshop how wide to make your image.
Plug-Ins and Scratch Disks
Photoshop is a memory-intensive application, so this preference pane lets you assign separate hard drives to increase Photoshop's memory allocation.
- Scratch Disks. When Photoshop runs out of RAM, which is the fastest memory in your computer, it uses empty hard drive space as temporary RAM. The preference options let you assign first, second, third, and fourth choices for which hard disks, called scratch disks, Photoshop should use as scratch space. You should always assign your fastest drive with the largest amount of free space as the primary scratch disk drive.
Tip
Memory and Image Cache
- Cache Settings. The image cache enables Photoshop to increase the apparent speed with which it deals with large images. Using the number specified here, Photoshop saves several smaller versions of the image at different zoom percentages (that is, 25%, 33.3%, 50%, and 66.7%). When viewing the image in a zoomed-out view, the program can apply the changes to a smaller, cached version first and update your screen preview faster. The default setting is 4 cache levels, which works just fine for most images. If you find that you're working on really large images and you have a good allocation of RAM, you might try increasing it to 6.
- Use Cache for Histogram in Levels. This preference should be turned off! Its sole purpose is to speed the rendering of histograms in the Levels dialog box when you are working on your image at views other than 100%. Although the speedier histogram may seem like a good thing, you're not getting the real histogram from the full image. Rather, you're getting a histogram rendered from whatever cached version happens to be presently in use. If you're going to make the effort to understand what the histogram is telling you, you might as well be getting the accurate data.
- Memory Usage. This section shows you how much available RAM you have and how much of it should be assigned to Photoshop. Both Windows and Mac OS X use dynamic memory allocation, so the number is not necessarily as specific as it may seem in this preference. I generally use 90 percent of available RAM for Photoshop. If you are running a lot of programs or you find your system getting cranky, you may need to lower this amount, install more RAM (always a good idea), or try closing some applications. Of these options, getting more RAM is the best one. You can never have too much RAM with Photoshop, especially now that you can work on 16-bit layered images.
File Browser
- Allow Background Processing. This preference tells Photoshop to grab on to any extra available processing power and use it to generate previews and thumbnails for the selected folder of images, even if you're not currently working in the File Browser or Photoshop. This is very useful for setting up the File Browser to work on a large folder of new images before you actually start browsing the files. I like to target the folder in question and then work on other tasks (or just go have dinner), so that when I return, all the thumbnails and high-quality previews are ready to use.
- Keep Sidecar Files with Master Files. The sidecar files contain additional information about images generated by the File Browser. By default, this preference is turned on. It lets you move, copy, delete, rename, or batch rename the data, along with the associated image files. I suggest leaving this option on.
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Table of ContentsCOLOR SETTINGS
The Color Settings dialog box is mission control for how Photoshop handles the display and conversion of color in your images. Understanding what goes on here and choosing the appropriate settings is key to controlling color in Photoshop and maintaining the color fidelity of your photographs. Although the settings are executed in the background, this dialog box is one of the most important areas in the program: The settings you choose here affect how images are opened, what happens to pixels when you paste from one image into another, how colors are displayed on your monitor, and how much notice you get if a particular process may change the colors in an image. It's well worth your time to get to know the different options in this dialog box and understand how they impact your image-editing workflow.
How Photoshop Handles Color
Before I get into the details of the Color Settings dialog box, let's pause for a moment to get a good overview of the terrain I'll be exploring. It doesn't do any good to simply tell you what settings to choose, which checkboxes to check and what radio buttons to enable if you don't have an understanding of the conceptual foundations of the Color Settings dialog box and Photoshop color management in general.
When distilled to its most basic components, a digital image is nothing more than an electronic paint-by-numbers kit. The image is made up of a grid of pixels, with each pixel's color, or tone if it's a grayscale image, represented by a number. In the case of an RGB image, each pixel has three values, one each for red, green, and blue. True, when you're working on an image in Photoshop, it probably feels a lot more high-tech than a paint-by-numbers kit, but all you're really doing when you edit a digital image is changing the color of the pixels. The numbers that are assigned to the pixels tell Photoshop how to display each pixel on your monitor, or they tell an output device what color each pixel should be when the image is printed.
The problem with this arrangement is that it comes with a certain amount of ambiguity. A paint-by-numbers picture, divided into separate areas that call for specific colors, will look very different depending on whether you use watercolors, oils, acrylics, colored pencils, or chalk pastels. With digital color, the actual color you get, whether displayed on a monitor or printed by an inkjet or photographic printer, will vary from device to device, simply because different devices interpret the numbers and render color in different ways.
In an effort to standardize how digital color is displayed and printed, color management in Photoshop revolves around four key principles:
The Importance of Monitor Calibration and Profiling
The importance of controlling your viewing environment and having an accurately calibrated and profiled monitor cannot be emphasized enough. Simply put, if your monitor has not been properly adjusted (calibrated) and the profile that describes it is not accurate, no amount of color management diligence and use of image color tags farther down the pipeline will give you predictable color. If you have never created a profile for your monitor (at the very least you should use the calibration utility that comes with your computer's operating system), I recommend postponing any serious printing of your images until that vital piece of the puzzle has been resolved.
Note
The Importance of Working Spaces
A working space defines how Photoshop will interpret the color numbers in a file and gives some visual meaning and consistency to the numbers that make up a digital image. The working space will affect any new images you create in Photoshop and images that do not already have a profile associated with them (as is often the case with files from a digital camera). Because the working spaces that are available in Photoshop do not represent color as defined by a particular device, such as a monitor or printer, as long as an accurate monitor profile is being used and an image is saved with a color profile (more on that shortly), then the display of the image will be consistent when viewed on other calibrated and color-managed systems.
The Importance of Color Profiles
If you gather five people in a room and ask all of them to close their eyes and think of the color purple, it's very doubtful that everyone would imagine the exact same color. Apart from obvious brightness differences such as light purple and dark purple, there are also subtleties of hue and saturation to consider. Is it a deep bluish purple, or a purple with traces of intense magenta? With no way to precisely define the color, the range of imagined purples would be all over the map. To accurately convey a more specific idea of what type of purple you are talking about, you would need to provide some additional information. In a digital image, an ICC profile is the additional information that ensures the colors in the image are being interpreted properly.
A color profile is essentially just a label that describes how the colors in an image should be displayed or printed. Along with a monitor profile and a device-independent working space, it represents the third crucial component in how Photoshop handles the colors in the images you work on. Any file you work on in Photoshop should be saved with an embedded color profile (this option can be found in the Save As dialog box). The presence of a profile tells Photoshop and other ICC-aware applications how the colors should look. I cannot stress enough the importance of having a profile associated with your image. In the words of color management experts Bruce Fraser and Andrew Rodney, without an embedded profile, your file is just so much RGB “mystery meat.” Photoshop has no idea how to display the colors, so it just displays them according to the working space, which may represent a correct interpretation, but then again may not.
CONFIGURING THE COLOR SETTINGS
With that history lesson and important background information out of the way, let's turn our attention to the actual Color Settings dialog box and discuss some of the choices there. On Mac OS X, this dialog box can be found under the Photoshop menu; on Windows, it's found in the Edit menu. Or you can simply press (Cmd + Shift + K) [Ctrl + Shift + K].
The Settings Menu
The settings pop-up menu is at the very top of the Color Settings dialog box and contains a collection of preset configurations tailored for different purposes. If you have never changed these settings, it's likely they are still set at the defaults, which, while not catastrophic, are certainly not the best settings for serious photographic work with Photoshop. In Photoshop 6 and 7, the default settings are configured to Web Graphics Default unless you customize them when you first open the program after installation or later on. In Photoshop CS, the default settings have been changed to North America General Purpose Defaults, which for all practical purposes are no different than the previous set of defaults. Again, while use of these default settings doesn't herald the end of the world in terms of color quality, they're not ideal.
To quickly get to most of the settings that I recommend for photography, you can choose U.S. Prepress Defaults from the Settings menu (figure 1.21).
Figure 1.21. View of the opened Settings menu from the Color Settings dialog box, with U.S. Prepress Defaults active.
RGB Working Spaces
Photoshop provides you with four choices for RGB Working Spaces and of these, only two are serious contenders for those who care about good color reproduction. Unfortunately, neither of them is included in the default settings. Let's take a look at them in greater detail. I'll list them in order of preference, rather than how they appear in the Working Space pop-up menu.
- Adobe RGB (1998). This is my preferred working space and, with few exceptions, it's the one I recommend for digital photographers. If you chose U.S Prepress Defaults from the settings menu, Adobe RGB (1998) is already selected for you. This RGB working space has the largest color gamut of any of the four spaces provided by Photoshop. If you're producing images for reproduction on a printing press, the gamut of Adobe RGB includes nearly all of the colors that can be found in the most commonly used CMYK gamuts. The only potential drawback of using Adobe RGB for prepress work is that it extends pretty far out into the brightly saturated greens—colors which in most cases would be impossible to reproduce on press.For any printed output of your photographs on RGB devices, whether that be on inkjet printers or photographic printers such as a Lightjet 5000, Adobe RGB (1998) encompasses most of the color gamuts of those devices and is the best choice of the available RGB working spaces in Photoshop. But if you're preparing files for specific output devices, it's always a good idea to check with your output provider to see whether they have different recommendations. Many consumer digital photo printers, such as the Fuji Frontier, use sRGB as their target output profile.
- ColorMatch RGB. This working space is based on the gamut of an actual device, the Radius Pressview monitor that was once ubiquitous in prepress shops. After Adobe RGB (1998), this is the other logical choice to use, particularly if you are preparing images for press reproduction. Although the gamut of ColorMatch is much smaller than Adobe RGB (1998), it does include most of the common CMYK gamuts. Because it does not include as many intense, saturated colors as Adobe RGB (1998), some people prefer this space for work that will end up on press because the saturation of some of the colors they see on their monitor will more closely resemble what the image will look like when it is finally converted into CMYK.
- sRGB. This is Photoshop's default RGB working space, so if you have never changed it, or if you just accepted the defaults when you installed the program, it's probably still set to this. If I had to describe this working space in a few words, those words would be “the lowest common denominator.” In an effort to place some reference on what they felt most of the world was seeing on their monitors, Microsoft and Hewlett-Packard developed the sRGB space to represent the gamut of the “typical” monitor. Because most of the world is probably using cheap monitors that are not designed for imaging work, sRGB is nothing to write home about. If your work is destined for a printing press, sRGB is not advisable because it produces considerable clipping of colors (that is, it cannot reproduce them), especially in the cyan range.With prints made from desktop inkjet printers, which is arguably what many digital photo graphers are most concerned with, sRGB is similarly gamut-challenged. Because most cameras use a variation of sRGB as their internal space for creating photos from the data produced by the CCD, you might think it makes sense to simply use sRGB in Photoshop as well. While not catastrophic for casual use (that is, emailing photos, dropping them into a Microsoft Powerpoint presentation, Web graphics, or hobby-printing), it's not ideal for printed output. Suffice it to say, if you really care about color quality, you can do much better. I recommend Adobe RGB (1998) over sRGB any day.
- Apple RGB. I'm not sure why Apple RGB is still offered in Photoshop. In computer terms, it's something from the fossil record (the polite way of referring to it would be to call it a “legacy” working space). In Photoshop 4 and earlier, the default color space (it didn't let you choose your own back then) was based on an Apple 13-inch monitor, hence the inclusion of Apple RGB in the list of choices here. Unless you're just nostalgic for the past (otherwise known as the “dark ages before color management”), there is no good reason for you to choose this as a working space.
- Many people assume that the best working space to use is one that describes their monitor, camera, scanner, or printer they will use to print the final image. This is a false assumption. You should never, ever use a device profile as a working space in Photoshop. For one thing, a working space based on a specific device, especially a monitor, may not contain all the colors your output device can render. Another reason is that device profiles are rarely neutral (also known as gray-balanced), which means that equal amounts of red, green, and blue yield a neutral color. Photoshop makes this critical assumption in color correction and blend mode calculations. To play it safe, stick with one of the four working spaces that ship with Photoshop. My recommendation is Adobe RGB (1998).
CMYK Working Spaces
Before I get into the different factors that determine what CMYK working space you should choose, let's get one thing straight: You only need to be concerned with this setting if the images you're working on will be reproduced on a commercial printing press. Even though desktop inkjet printers use cyan, magenta, yellow, and black inks, they are considered to be RGB devices because they do such a great job of taking the RGB data you give them, converting the RGB information into the color of ink they use, and most importantly making nice prints. If you don't need to convert images to CMYK for prepress purposes, you don't need to trouble yourself with this setting, and you can safely skip ahead to the next section.
Although RGB working spaces are device- independent, CMYK is very output specific, and the settings are influenced by such things as the type of inks, the paper being used, and, in some cases, the characteristics of the individual printing press. So it's not as easy to give a one-size-fits-all recommendation for the best space to use. This is also not a CMYK book, so our coverage of this area is not indepth. I can, however, talk about the default settings and some of the presets that are included with Photoshop that represent a good start. Knowing a bit more about these will help point you in the right direction should you find yourself having to prepare images for reproduction on a press. I also believe in acknowledging the expertise of those whose experiences and advice I value—Real World Adobe Photoshop CS by David Blatner and Bruce Fraser is an excellent resource for anyone who needs to use Photoshop with CMYK.
If you're in the United States, using the default U.S. Web Coated (SWOP) version 2 is probably as safe a choice as any for a default setting. The term web here does not refer to the World Wide Web, but to a web press, which uses huge rolls of paper fed through the press at incredible speeds (think of those montage shots in old movies where you see the newspapers flying by on the printing press in the background and the momentous front page spins into view in the center of the screen). The term coated refers to the fact that paper has a very thin coating that is designed to produce sharper text and images with more saturated ink coverage. This book is printed on coated paper, for example, as are most magazines and high-quality publications. If the press uses individual sheets of paper, as opposed to the large rolls on web presses, you might choose U.S. Sheetfed Coated v2. If you were printing on uncoated paper, which is generally duller and less glossy, you would use one of the settings for uncoated paper stocks.
Because CMYK settings are so tied to how the job will be reproduced, any setting you choose should be thought of as no more than a general placeholder that will suffice for the most common printing situations. Depending on the work you do and the type of publications in which it appears, one of the supplied presets may be just fine, but you should always maintain good channels of communication with your publisher or printer and verify you are using the right setting. While I was working on this book, for instance, I used two specific CMYK setups supplied to me by the publisher: one for images and the other for screenshots.
Gray Working Spaces
Gray working spaces can be selected to reflect specific dot-gain characteristics or display gammas. Dot-gain percentages refer to the fact that when printed on a press, a dot of ink will increase in size, and therefore become darker, as it is imprinted and absorbed into the paper. The gamma settings are designed for images that will be viewed on a monitor but also work well for images that will be printed on an inkjet printer (more on that shortly).
If your primary output is to a printing press, choose a dot gain that matches the same figure in your CMYK setup. For instance, a common percentage for coated stock is 20, which is the default in Photoshop CS. As with CMYK, however, mileage and dot gain may vary depending on the particular inks and paper being used, so consult your printer to get as much information as possible.
If you're printing black and white images to a desktop inkjet printer, I recommend setting the Gray Working Space to Gray Gamma 2.2. This is true even if you're on a Mac, which still uses a default display gamma of 1.8. A gamma of 2.2 (here and in your monitor calibration) will produce smoother gradients than a gamma of 1.8. If you're on a Mac and will be opening earlier grayscale files created using a gray gamma of 1.8, you will be notified that the embedded profile does not match the current gray working space of 2.2. In that case, just choose Convert to Profile, and the tones in the photo will be converted with an eye toward preserving the appearance of the image.
Spot Working Spaces
This setting is very specific and refers only to specialized prepress situations where custom inks (that is, other than the standard process colors of CMYK) will be used. It does not apply to working on your digital photographs. Because you'll probably never use it, the default setting is fine. If you need to use it at all, check with your printer about the specific dot-gain characteristics of the ink, paper, and press that will be used to print the job.
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Table of Contents
COLOR MANAGEMENT POLICIES
This section of Photoshop's Color Settings tells the program how to behave when it encounters an image that either does not have a profile (untagged) or has an embedded profile that does not match the currently selected working space (mismatched). This is the place that controls those annoying warnings that appear when you open an image in Photoshop. Well, some people feel they're annoying, but once you understand what they're telling you, they're not so bad.
There are three separate pop-up menus for setting the policies for RGB, CMYK, and Gray working spaces (figure 1.22). All contain the same three choices: Preserve Embedded Profiles, Convert to Working RGB (or CMYK, or Gray), and Off. These choices are the same ones that appear in the warning dialog boxes when you open images, although the exact wording is a bit different What you select here just determines which radio button is selected by default when the warning dialog box pops up. Let's take a look at exactly what these choices mean. I'll discuss them in order of our preference, rather than how they appear in the menu.
- Convert to Working RGB. When a file is opened that has a different color tag than your working space, this choice will convert the image from the embedded space into your currently selected RGB working space. This is your best choice if you're working in a closed loop system (that is, you're generating all of your images from your scanner or digital camera), you know where all of the files are coming from and that they have accurate profiles, and you're using a working space such as Adobe RGB (1998).
- Off. If you open a file that contains an embedded profile, Photoshop will throw away the profile and regard the image as untagged. The color numbers in the file will be interpreted according to the currently selected working space, even though that may not be a correct assumption. Because I believe profiles (if they are accurate) can help you take control of the color in your digital images, it's probably no surprise that I think this is a really bad idea. By stripping the profile from the image, you are flying blind as to the true meaning of the color numbers, and Photoshop can only display the file as if it matched your working space. There is no good reason to choose this setting.
Figure 1.22. The Color Management Policies control whether you see a color profile warning dialog box when you open a file.
Profile Mismatches and Missing Profiles
These three checkboxes control whether you see those pesky missing or mismatched profile notices when you open a file. If you can't stand them and never want to be bothered by them again (and I hear this sentiment a lot!), you can turn them off here. I recommend you leave at least two of them on, however, because it's always good to be in formed about what's happening with the color in a file. The most important ones are the Ask When Opening options that trigger a notice if you open a file that either has no profile or has a profile that does not match your working space. The last one, which you can safely turn off (it drives me crazy!), is the Ask When Pasting option. This triggers a notice when you paste from one image to another and the profiles of the two don't match. In nearly all cases, the answer to the question it poses is the default one, which is to convert the color numbers so that the image appearance is preserved.
How to Deal with Profile Warnings
One of the most common questions I get from students and new Photoshop users is what to do about the missing profile and profile mismatch warnings that seem to pop up every time you open a file, as shown in figure 1.23. If you don't know what they're telling you or what the right answer should be, encountering these can be very frustrating. To make matters more perplexing, they use language that is slightly different from that used in the Color Management Policies section. In an effort to clear up some of the confusion surrounding these warnings, here are some recommendations on which choices are appropriate when you run into them.
Figure 1.23. The Embedded Profile Mismatch dialog box.
Profile Mismatch situations are the easiest to deal with because Photoshop detects a profile associated with the image, which gives it the necessary information to convert the color numbers from the existing profile into your current RGB working space. Of the three choices presented to you, only the first two are really an option.
The Use the Embedded Profile option will honor the existing color tag and you will be able to edit the image in its native space, as though your working space had been temporarily changed to match the profile of the image. This choice is the same as the Preserve Embedded Profiles menu option in Color Management Policies.
The Convert Document's Colors to the Working Space option is probably the more logical choice for most digital camera owners (assuming that the profile is correct). The most likely scenario you will encounter is opening a digital capture where the camera has tagged it with an sRGB profile. Because it's far better to edit an image in the Adobe RGB (1998) space than in sRGB, converting to the working space makes a lot of sense. The conversion will preserve the image's appearance, so while actual color values in the image may change, it should look exactly as though you had opened it by choosing to preserve the embedded profile. This choice is the same as the Convert to Working RGB option in Color Management Policies.
The final choice, Discard the Embedded Profile (Don't Color Manage), should not be used. This is the same as the Off choice in the Color Management Policies. The profile is removed from the image and the colors in the file are interpreted according to the working space, which is essentially just Photoshop shrugging and saying, “I dunno, let's try this.” The only reason I can think of to ever use this option is when you're certain the embedded profile is wrong and you want to remove it so that you can assign a new one.
If you open an image that has no embedded profile, Photoshop has no reference to rely on. In the Missing Profile dialog box, it asks you how you want it to interpret the color numbers in the file. If you are only opening files from your digital camera, you can usually figure out the right choice with a little testing. For one thing, most consumer level digital cameras create files that look pretty good when opened as sRGB files. If your camera lets you shoot into the Adobe RGB (1998) space, you can always select that, or simply convert into the working space if you're using Adobe RGB (1998). The next few paragraphs detail what the three choices in the Missing Profile dialog box (see figure 1.24) mean.
Figure 1.24. The Missing Profile dialog box.
The Leave As Is (Don't Color Manage) option is similar to Off in the Profile Mismatch Warning dialog box, with the exception that because there is no profile to start with, nothing gets stripped from the image. Photoshop opens it, interpreting the colors according to how the working space thinks they should be displayed, whether that is correct or not.
The Assign Working RGB option essentially does the same as the previous choice, with the only difference being that it slaps the profile of the working space onto the image. Because no color numbers have changed and the image is being displayed based on the specification of the working space, the appearance of the image will be identical to how it would look if you had chosen Leave As Is. This choice is appropriate only if you know that the file matches your working space.
The Assign Profile option lets you choose a specific profile and then convert to the working space after the profile has been assigned. This is a good choice if you know, for example, that sRGB works well for your camera's images but they still open up as untagged. You can choose sRGB from the pop-up menu and then click the Convert to Working RGB checkbox. The momentary presence of the sRGB profile gives Photoshop enough information to make a correct conversion to the working space. The only thing missing from this choice is a preview so that you can see how a different profile is affecting the image. But, because the image isn't even open yet, there's no way to see a preview.
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