Photoshop cs5 by steve Johnson part 67 ppsx

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 a

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18 What You’ll Do

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

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 workprint-ing 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

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

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

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in color calibrator While this section deals with manual calibration of your monitor, it is highly recommended that you purchase 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

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 calibrate a monitor, you will need 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 calibrate a printer, you will need a digital 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

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)

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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 save a customized profile setup,

click Save.

To load a previously saved profile

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

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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

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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

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