Photoshop cs5 by steve Johnson part 67 ppsx

ptg 18 18 What You’ll Do 423 Managing Color from Monitor to Print Introduction Color management has changed a lot in the last few years. New standards have been defined, and Adobe is at the fore- front of this new technology. No longer do you have to fear color management, because Adobe Photoshop has taken all (or at least most) of the guesswork out of the equation. Adobe's color management system (CMS), provides different rendering intents, or ways to translate color definitions between the input device and the output device using color profiles to avoid color-matching problems. When you work on a computer monitor, you're viewing color information in the RGB (Red, Green, and Blue), additive color space. When you move into the world of the 4-color press, you're viewing color information in the CMYK, or sub- tractive color space. While a standard color press is called a 4-color press, in reality, only three colors are used—CMY (Cyan, Magenta, and Yellow—the opposites of RGB). To gen- erate a true black, a printer must use the "K" plate (K stands for black, or key plate). Monitors display RGB colors very dif- ferently; when you factor in monitor resolutions, and the dif- ferent types of monitors in the marketplace, what you see on a computer monitor is seldom what anyone else sees on their monitors. And that's not all; everyone who owns a com- puter has the ability to adjust or calibrate the colors on their monitors differently, further confusing the issue. While nothing is perfect, the world of professional print- ing is more controlled. For example, when you're working on a color document that is moving to press, you can use a pre- determined set of colors, such as the Pantone Matching System. The Pantone colors come printed on special card stock. When you're looking for a specific color, you choose it from the card stock, and then that information is given to the press operator. This type of control, even including the type of paper, keeps you in charge of the process of moving from monitor to print. What You’ll Do Produce Consistent Color Calibrate Using Hardware and Software Set Up Soft-Proof Colors Change from Additive (RGB) to Subtractive (CMYK) Color Work with Rendering Intents Print a Hard Proof Work with Color Management Embed ICC Color Profiles Assign a Different Profile to a Document Convert the Color Space to Another Profile Use Hue/Saturation for Out-Of-Gamut Colors Use the Sponge Tool for Out-Of-Gamut Colors Work with the Out-Of-Gamut Warning From the Library of Wow! eBook ptg 424 Chapter 18 Producing Consistent Color You can create consistent color in Photoshop by following some basic steps: If you are working with a production company, consult with them to make sure they provide you with any necessary software and hardware configuration and color management settings. Calibrate and profile your monitor. See “Calibrating a Monitor” on this page. Add color profiles to your computer for your input and output devices, such as a printer or scanner. Color profiles are typically added to your computer when you install the device. Photoshop uses the profile to help determine how the device produces color in a document. Set up color management in Adobe programs. See “Working with Color Management” on page 432. Preview colors using a soft proof (optional). See “Setting Up Soft-Proof Colors” on page 426. Use color management when printing and saving files. See “Saving a Document” on page 28 and “Setting Document Print Options” on page 382. Calibrating a Monitor (Manually) Photoshop comes with its own color manage- ment system; however, before you can suc- cessfully use color management, you must first calibrate your monitor to a predefined standard. There are several methods available to you for monitor calibration. One is to pur- chase a third-party calibration system, while another is to use the operating system's built- 6 5 4 3 2 1 in color calibrator. While this section deals with manual calibration of your monitor, it is highly recommended that you purchase cali- bration equipment, or hire someone to cali- brate your system, because the human eye is not the best device to color manage a system. Before beginning the calibration process, let your monitor warm up for thirty minutes to an hour, and calibrate under the same lighting system that you'll be using when you work. To manually calibrate your computer monitor, on Windows, select the Adobe Gamma utility located in the Control Panel. For Macintosh users, select the Calibrate Utility by opening System Preferences, clicking the Display icons, clicking the Color tab, and then clicking Calibrate. In the calibration application, you will be instructed to manually balance the monitor for various shades of red, green, and blue, or to pick from a set of predetermined calibration settings. Since the human eye is not the best device for adjusting color, this method produces less-than-desirable results. Producing Consistent Color Macintosh Calibrate Utility From the Library of Wow! eBook ptg Chapter 18 Managing Color from Monitor to Print 425 The digital tools available today are so sophis- ticated that just 10 years ago, no one would have thought them possible. Color calibration falls into three categories: Input (digital cam- eras, scanners), Processing (monitors), and Output (printers, presses). Each category requires calibration to create a workflow between devices. Remember a few things before you calibrate your system: Let moni- tors warm up for 30 minutes to an hour before doing the calibration, and calibrate the system using the same lighting levels in which you will be designing. Once the calibra- tion of all your devices is complete, you can expect the best color consistency that technol- ogy can provide. Several companies market color calibration hardware and software; one of them is ColorCal at www.colorcal.com . Calibrate a Monitor (Processing) To ca lib rat e a mo ni tor, y ou w il l nee d to pur - chase a digital device called a colorimeter, or spectrophotometer. When you launch the cali- bration software, it typically displays a color target in the middle of the monitor. You would then attach the device to the monitor, directly over the color patch, and follow the step-by- step instructions. When complete, the soft- ware creates a digital color profile for the monitor and PostScript output devices use that profile to accurately print color images. Calibrate a Scanner and Digital Camera (Input) Calibration of a scanner and digital camera requires the scanning or photographing of a reference color target with known color val- ues. For example, the Kodak Q-60 IT8 color target has 240 color patches, a 24-step grayscale, and reproduction of flesh tones. The calibration software reads the scanned colors and compares them to known color values to create a table of how the camera or scanner performs. Scanning a color target is easy. You lay the target on the scanner, close the lid and push the button. Digital cameras are a bit more difficult because you have to deal with the lighting conditions at the time the target was shot. With studio cameras this isn't a problem; however, taking photographs in ambient lighting involves different times of day, sunny versus cloudy, and incandescent versus fluorescent lighting. Yet, even factoring in the potential problems, calibrating your camera goes a long way in stabilizing color information on a digital camera. Calibrate a Printer To ca lib rat e a pr in ter, y ou w il l nee d a di gi tal target file. The file is sent directly to the printer. Once printed, the results are checked with a spectrophotometer, and then the soft- ware measures the colors against the target values and creates a profile. There are many variables involved in the printing process, such as the type of inks used, and the type of paper used for printing. Therefore, calibration is performed based on the fact that you will be using the same ink and paper combina- tion, so the calibration process should be per- formed each time you purchase new ink cartridges and/or change the paper type. Calibrating Using Hardware and Software From the Library of Wow! eBook ptg 426 Chapter 18 When you work with a printer, you traditionally print a hard proof of your document, and visually preview how the colors look. Then you sign off on the proof, and the press operator begins the run. In Photoshop, you can use color profiles to soft-proof the document. Color profiles are a way to display the colors of a specific device directly on your monitor. While not as exact as a hard proof, it can go a long way to getting the colors of a CMYK document into the range of the output device. It's important to understand that the results of the soft proof compared to a hard proof is directly dependent on the quality of your monitor and monitor profiles. When you soft-proof a document, you're temporarily assigning a color profile to the document. Setting Up Soft-Proof Colors Understand How to Soft-Proof Colors Open a document (to use soft proofing, the document does not have to be in the CMYK color mode). Click the View menu, point to Proof Setup, and then click Custom. Click the Custom Proof Condition list arrow, and then select from the available customized setups (check with your press operator). Click the Device to Simulate list arrow, and then select from the available color output devices. Select the Preserve Numbers check box to simulate how the colors will appear without conversion. Click the Rendering Intent list arrow, (available if Preserve Numbers is unchecked), and then select from the available options to view how the colors will convert using the proof profile colors, and not the document profile. Select the Black Point Compensation check box to map the full dynamic range of the source space (recommended). 7 6 5 4 3 2 1 5 7 1 3 4 6 From the Library of Wow! eBook ptg Chapter 18 Managing Color from Monitor to Print 427 Select the Simulate Paper Color check box to simulate the visual conditions of white paper as defined by the current profile. Select the Simulate Black Ink check box to map the full dynamic range of black as defined by the current profile. To sav e a cu stom ized pr ofile se tup, click Save. To loa d a pr evio usly sa ved prof ile setup, click Load. Check with your press operator; in many cases they have profiles set up to match the dynamic range of their presses. Click OK. Click the View menu, and then click Proof Colors to view the color profile for the active document. 13 12 11 10 9 8 8 9 12 10 Understanding Soft-Proof Colors If your monitor is properly calibrated and you have accurate profiles of your output devices, you can use Photoshop's soft-proof capabili- ties to preview how your image will look when printed to your desk- top printer, sent to a printing press, or even when viewed on a par- ticular computer operating system. The viewing capabilities of the Proof Setup option are only limited by the availability of output device profiles. If you don't have a specific profile, check with the manufacturer; many times they will have the device profiles avail- able and, in most cases, for free. For Your Information 11 From the Library of Wow! eBook ptg 428 Chapter 18 RGB (Red, Green, and Blue) is defined as an additive color space, in which primary colors are added together to produce other colors. RGB is the color space of computer monitors, televisions, and most PDAs and cell phones with built-in color screens. A monitor uses pixels (small square or rectangular bricks), and each pixel mixes a combination of red, green, and blue to project a specific color to your eyes. Pixels use (on average) 24 switches to hold color information, and can produce 1 of 16,777,216 separate colors. CMYK (Cyan, Magenta, Yellow, and Black) is defined as a subtractive color space. CMYK is the color space of high-end inkjet, laser, and professional presses. A press uses plates that define each of the 4 colors; as a piece of paper passes through the press, the colors are applied from each plate. The term subtractive comes from the fact that the inks used in printing absorb or "subtract" a portion of the spectrum in order to produce other colors. Since a press cannot generate the intense saturation of an electronic pixel, the num- ber of possible colors is reduced into the thousands. However, when used correctly, you can produce some stunning results. It's a simple matter to convert a Photoshop document into the CMYK mode; how- ever, good planning will ensure the colors you want will be the colors you get. Changing from Additive (RGB) to Subtractive (CMYK) Color Change from RGB to CMYK Color Open a document. IMPORTANT You cannot convert a Bitmap or Multichannel document directly into CMYK mode. Convert a Bitmap image to Grayscale, and then to CMYK; convert a Multichannel to RGB, and then to CMYK. Click the Image menu, point to Mode, and then click CMYK. Photoshop converts the RGB image into CMYK. If the RGB colors are not supported by the CMYK color space, they will be converted into the closest subtractive color values. 2 1 1 Image converts to CMYK From the Library of Wow! eBook . Wow! eBook ptg 424 Chapter 18 Producing Consistent Color You can create consistent color in Photoshop by following some basic steps: If you are working with a production company, consult with. conditions of white paper as defined by the current profile. Select the Simulate Black Ink check box to map the full dynamic range of black as defined by the current profile. To sav e a cu. CMYK. Click the Image menu, point to Mode, and then click CMYK. Photoshop converts the RGB image into CMYK. If the RGB colors are not supported by the CMYK color space, they will be converted into