Part I: Color Management Overview | Part II: Monitor Profiling | Part III: Color Settings | Part IV: Printer Profiling

As a photographer, you spend plenty of time capturing the perfect moment, evaluating the quality of the light and understanding how to process, store and print photos in digital darkroom programs like Adobe Photoshop, Lightroom or Apple’s Aperture. The last thing you want to worry about is whether the colors in your photos will be as vibrant, as rich, or as accurate as you saw with your eye and adjusted on your monitor.

That’s why digital photography has become the choice among professionals and amateurs alike; digital ensures your photo preview on the back of your camera looks close to the same as the photo printed on your inkjet, through a digital photo lab or posted online. You get this kind of quality because of effective color management that’s built into every step in the digital workflow and embedded into your photographs. While this process isn’t yet perfect, it is quite robust and requires only a minimal introduction into the technical underpinnings for you to make color management work for your photos.

The goal of this four-part series is to help you improve the color consistency and color accuracy in your digital photography workflow from image capture to print. We’ll begin this month with Part I, a high-level overview of color management—what purpose it serves and how it works. Part II addresses the cornerstone of an effective digital photography workflow—the monitor—with recommendations on how to select an appropriate monitor and how to calibrate and profile the monitor to ensure accurate on-screen color. Part III helps you configure the color management options in the major image editing and correction applications. Part IV tackles color management in the print process, a source of frustration for many photographers.

The knowledge you’ll gain from these articles will take you beyond simple button pushing and give you a deeper mastery of color management because you’ll not only learn how to use it, but you’ll learn how and why it works so well.

The Role of Color Management in Accurate Final Photos

The philosophy of color management is simple. Digital photographs should look the same at every stage of the digital photography workflow. From image capture to print, your photo should look substantially the same, without significant color shifts, changes in contrast or loss of highlight or shadow detail.

In concept, color management is rather straightforward. In practice, it’s significantly more complex. Fortunately, the hardware and software used to implement and support color management has become significantly easier to use and more effective than it was even a few years ago. This makes the benefits of color management accessible to everyone, not just serious professionals with full-time studio assistants. If nothing else, learning to calibrate your monitor effectively, adjust color settings in your imaging software and deftly navigate the options in your printer dialog will make your digital photography workflow faster, more effective and far less frustrating.

ICC-based Color Management: The Foundation of A Successful Workflow

Conventions and standards help make life easier. When you get into any car, you know the gas pedal is on the right and the brake is to the left of the gas. This convention allows a routine to become automatic and prevents you from having to figure out how to work a car every time you get behind the wheel.

This is the idea behind the International Color Consortium (ICC). It is the governing body for color management standards, development and implementation. Like having the gas pedal on the right, standards-based color management makes it easier for software developers to support color management and for end users to use color management effectively by setting standards that most everyone can agree upon using.

The greatest contribution of the ICC is the creation of a modular, ICC-based workflow which makes it easy to prepare a single photo for many different output purposes. Prior to ICC profile, film was scanned and a digital file was created for optimal reproduction on one type of printing press. If a client wanted to change papers or use a different printing method, the file would need to be rescanned as each digital file would only print correctly on one device. This was referred to as “closed loop” color management. The creator of the digital file needed to know exactly how the digital file would be used, otherwise the photo would not print correctly.

We’ve come a long way since then. Today, a photo you create can be printed on your inkjet printer, uploaded to a photo-sharing site where your friends may order prints or a photo book. All this, created from a single file. This is color management in action.

The Secret to Success: Color Profiles

The secret to the success of color management is the adoption and use of color profiles. A color profile mathematically describes the color and tone characteristics of a specific device including paper and ink type, where appropriate. The range of colors reproducible on a given device is commonly referred to as a color space. Through the use of color profiles, we can convert a photo between different color spaces, without significantly changing the appearance of the photo.

You’ve already been using ICC-based color management whether you realize it or not. Whenever you print a photo on your inkjet printer, a conversion occurs between the color space selected on your digital camera or scanner and the printer’s color space used to ensure the colors are correctly matched between your camera and the printer. Often, this takes place automatically behind the scenes in the print software. If your print looked good, this process was successful. If not, poor color management was to blame.

To help ensure the next print is successful, let’s look at how color management works from a deeper perspective.

How ICC-based Color Management Works

ICC-based color management serves as a platform for converting a photo between color spaces to optimize the color values within the photo for a specific device or set of imaging conditions, while preserving the appearance of the photo as accurately as possible. It does this through the use of ICC profiles.

Camera ICC (Photo courtesy Olympus America Inc.)

Monitor ICC (Photo courtesy Eizo Nanao Corporation

Printer ICC (Photo courtesy Epson America, Inc.)

An ICC profile is a description of the color characteristics of a specific output device. Certain ICC profiles, like Adobe 1998, were created mathematically and don’t actually represent a specific device, though color management treats them that way.

In either case, the ICC profile contains information on the range of colors that can be reproduced with that output device. Most ICC profiles are created by displaying or printing a set of color patches and measuring the resulting colors. The difference between the actual color and the reproduced color becomes the basis for the profile.

As a photographer, it is important to understand that the RGB values you see in your color picker are unique to the ICC profile used for a given photo. The same RGB values in a different color space will create a different color. Here are three examples of the RGB color values 200, 15, 18 with different ICC profiles applied.

sRGB Swatch

Adobe 1998 RGB

Apple RGB Swatch

During the color conversion process, the RGB, CMYK or Grayscale values with your photos are translated from your original profile, often called the Source Profile, to the Destination Profile. This changes the color values in your photo to preserve the color appearance.

A color conversion between sRGB and Adobe 1998 changes the original RGB values of 200,15,18 to 170,23,26 while preserving the color appearance.

sRGB	Adobe 1998 RGB

In your digital photography workflow, you’ll be performing a series of conversions between color profiles, some you select, while others are automatic. Let’s look at the different types of color conversions taking place in your photographic workflow.

Where Color Management Fits Into Your Workflow

Whether or not you intend to, every stage of your digital photography workflow is color managed. For the best results, you’ll want to take control over the color conversions that occur in your workflow to prevent Photoshop and other applications from having to guess what the color should look like. These assumptions often cause a mismatch in color between your camera and your monitor or your monitor and your printer. In this section, I’ll walk you through each stage of your workflow, highlight the color management options and make recommendations on what settings you should choose.

Digital Camera/Scanner

At most stages of the workflow, you’ll want to use a profile specifically created for the unique characteristics of the device you’re using. Digital cameras are the notable exception. Unless you’re working in a studio, you’re better off using one of the two commonly used editing spaces, sRGB or Adobe 1998. Most digital cameras have these two options available in the menu on the back of the camera and use this profile for processing JPEG photos in camera.

Adobe 1998 is a wider color space and reproduces more vivid greens and reds than sRGB. This makes it a better profile for landscape and travel photographers. Wedding and portrait photographers often choose sRGB because it is the best choice for submitting photos to online photo printing and photo sharing sites.

If you are photographing in your camera’s raw mode, you defer this decision until you process the raw file in your raw editing software. Selecting Adobe RGB or sRGB will have no impact on raw files.

It is relatively easy to create a custom profile for your transparency scanner, but it is very difficult to get a good profile for your color negative film. If you’re new to color management, I’d suggest using Adobe 1998.

I’ll go into greater detail on the pros and cons of the commonly used editing spaces including Adobe 1998 and sRGB in Part III of this series.

Editing Software

Your image editing software allows you to specify a default profile used when processing camera raw files or when creating a new document. For most users, Adobe 1998 is ideal, though wedding and portrait photographers may wish to use sRGB to facilitate the printing process. Although sRGB is a smaller color space than Adobe RGB, skin tones, the most common color in wedding and portrait photos, lies well within the range of colors reproducible in sRGB, so there is no loss of quality.

Ideally, you’ll want to select the same ICC profile on your camera and in your editing software to prevent a color conversion when you process your JPEG photos. For raw shooters this isn’t an issue as ICC profiles are only applied when you process your photo from the raw format to a JPEG, TIFF or PSD.

Gotcha: One mistake many users make is setting their monitor profile as the default in their editing software. This complicates your image corrections and makes it more difficult to repurpose your photos for reproduction on different devices. You’re better served by instead selecting a common editing space like Adobe 1998 or sRGB.

Monitor

Of all the elements in your workflow, color managing your monitor is the most essential. Your monitor must be calibrated and profiled effectively, so you can be sure the blue cast you see in your photo is present in your photo, not imparted by your monitor. Investing in a monitor calibration package is one of the best investments a photographer can make.

Calibrating your monitor with a hardware and software package like the X-Rite Eye-One Display 2, $176, ensures what you’re seeing on screen is accurate. It doesn’t calibrate your monitor to anything, instead, by measuring the characteristics of your monitor and building an ICC profile describing these characteristics you can make tone and color adjustments more reliably knowing your changes are accurately represented in your photo.

Monitor calibration plays such an integral role in an efficient digital photography workflow that I’ve dedicated Part II of this series to helping you select a monitor, choose a monitor calibration package for your needs and budget, and helping you navigate the settings found in most monitor calibration software packages.

Printer

Often, the most important color management decision you have to make as a photographer is selecting the correct ICC profile for your printer and paper combination in the print dialog. This step, along with the settings in the print dialog, are the final hurdle between print nirvana and immense frustration. Understanding how color management works is an important first step. Part IV of this series will guide you through the pitfalls of printing and lead you to the promised land—photos that print correctly the first time, without any fuss or hassle.

Web

Color management on the Internet is considered by many to be an oxymoron. Most Web browsers don’t understand ICC color management and as a result there is almost no way to reliably predict what your colors will look like on the Web because you cannot control what monitors site visitors are using.

There are, however, steps you can take to stack the odds in your favor. The sRGB color space was designed to represent an “average computer monitor.” Now, we all know there is no such thing as an “average computer monitor,” particularly when the change from CRT to LCD monitors is all but complete and LED monitors are now arriving in photographer’s studios. Still, sRGB serves as a “best guess” for the Internet and I recommend that anyone preparing images for the Web or for e-mail convert their photos to sRGB before releasing them onto the World Wide Web.

Now that you better understand where color management fits into your digital photography workflow, let’s look at how the three major components—your monitor profile, your editing/working space, and your output (printing) profiles—work together.

Components of a Color Managed Workflow

The three major components of a color managed workflow work synergistically to ensure the quality and color of your digital photos is retained from the moment you press the shutter through the entire printing process.

Understanding how the monitor profile, editing space and output profiles work together helps you understand where color conversions are taking place and troubleshoot potential problems that arise in the workflow.

If we start with the camera, as soon as you press the shutter, the colors and tones in the scene are converted to a series of digital pixels. These pixels contain discrete red, green and blue values, which broadly define the color of the pixel. For example, we can tell that a pixel with RGB values of 220,7,15 is a shade of red, but we can’t tell which shade of red until we know what ICC profile is applied to the picture. As evidenced above, different ICC profiles interpret the same RGB color values differently.

On camera, you will likely have only two ICC profiles to choose from, sRGB or Adobe 1998. These two profiles are part of a larger classification of ICC profiles called editing spaces. These are sometimes referred to as Working Spaces, which is not technically correct as the term Working Space refers to a specific setting in Adobe applications instead of a classification defined by the ICC. Nevertheless, whether you say editing space or Working Space, it is assumed you’re referring to the common ICC profiles used for image editing, sRGB, Adobe 1998, Color Match RGB or Pro Photo RGB.

Each of these profiles has slightly different characteristics, but share one important attribute. Equal values of red, green and blue always equal a neutral shade of gray. Because these editing space profiles are mathematically created, (there is no Color Match RGB device to measure), editing spaces are superior for performing your tone and color corrections. Not only are they well-behaved and gray balanced, adjustments you make in these spaces are far more predictable than corrections made in a scanner or inkjet printer profile.

For these reasons, editing spaces are used for storing and editing all RGB files. For most photographers, you’re already working exclusively in one of the common editing spaces, either sRGB or Adobe 1998. If you are scanning film, you may have a scanner profile applied to your photos. If this is the case, I recommend converting your photos to an editing space before making corrections in Photoshop.

Monitor Profile

While your pictures’ color values should always be stored in an RGB editing space for performing corrections or archiving, your monitor profile must be applied before your photos will appear correctly on screen. Fortunately, this is done automatically by the operating system. You never have to manually perform any conversion to your monitor profile for your pictures to preview correctly on screen, it’s already done for you.

This process, known as display compensation, was the breakthrough that made color management effective for digital photography workflows. Display compensation separates the editing profile used for storing and editing a photo, with the monitor profile used to represent the photograph on screen. Your operating system accomplishes this by converting your photo from your editing space to your monitor profile on the fly as the pixel values are sent through your video card to your monitor. This conversion does not affect the original pixel values, only the ones displayed on your monitor, helping ensure the accuracy of what you’re seeing on-screen.

If this process sounds a bit too theoretical, here’s a practical example to help you understand how display compensation works and why it is so critical to have effective color management. You and I both have monitors we’ve profiled and calibrated. Your monitor is a little bit red from the factory and mine is a little bit green. Without color management, if you look at the photo, you’ll want to take out some red to make it neutral on your screen. I’ll want to take out some green to achieve the same effect. We’re both wrong; without color management we’d be taking a good file and making it worse.

Let’s run through the same scenario with color management applied. Since we’ve both calibrated our monitors, our monitor profile will automatically compensate for the variations in our monitors. Your monitor profile will display a little less red to ensure the photo appears a neutral gray on screen. Mine displays a little less green to appear neutral on my screen. What’s most important is the photo appears neutral on both of our screens. You and I can now agree on the appearance of the photo.

Remember, all this takes place automatically. Once you’ve calibrated and profiled your monitor accurately, display compensation works automatically. For additional piece of mind, I’ll show you how to check to make sure it’s working in Part II: Monitor Profiling.

Output Profiles

You’ll want to keep your photos in an editing space like Adobe 1998 while performing your corrections and when you archive your file for longevity. At some point though, you’ll have to convert your photo from an editing space to an output space for printing. If you don’t, your inkjet printer’s software will do it for you. You’ll have better success if you perform the correction manually. Since this is an introductory article, I won’t go through the process of preparing your photo for print. Instead, I’ll save that for Part IV of the article on Printer Profiles.

For now, it’s important that you understand you have to convert your photo’s colors from an editing space to your inkjet printer profile for your photo to print correctly. This conversion is necessary for three reasons:

1. Your printer is not “well behaved” or Gray balanced—remember how you can always create a neutral shade of gray in an editing space with equal values of red, green and blue? This doesn’t hold true for printers. Since your inkjet printer is an imperfect device instead of a mathematical construct, the RGB values needed to produce a neutral gray drop of ink are almost certainly not equal amounts of red, green and blue. For example, the black ink used in many printers is slightly reddish and to produce a neutral shadow, it must be mixed with cyan ink during the printing process to create a neutral black.
2. Paper White and Ink Black—in the mathematically perfect world of editing spaces, a white pixel RGB 255,255,255 is always white. In the real world of printing, you rarely print on white paper. If you look closely at your inkjet papers, you’ll see they are a little bit yellow, blue or even red. For your photo to look right, the colors in your photo have to be adjusted to compensate for the color of the paper. Additionally, an editing space shows detail in the shadows all the way to absolute black RGB 0,0,0. No printer can reproduce shadow detail perfectly. With all printers, there is a point at which the values are too dark to separate in the print and these areas print as pure black instead of detailed black. This point varies with the printer, paper and ink used. A good ICC profile for your printer will help you predict where this transition will occur and allow you to adjust your picture accordingly to ensure full detail in all your shadows. In Part IV of these articles, you’ll learn how to Soft Proof your photos and predict what your print will look like on screen.
3. Optimize the color values for printing—most importantly, converting your photo to the printer’s ICC profile during the printing process optimizes the colors and tones in your photo for printing. This improves the accuracy of your photo and will give you the best results with the least hassle in the printmaking process.

Benefits of Color Management

To summarize, the benefits of color management are:

• Predictable Printing—effective color management will help add predictability to your printing process, eliminating the frustration, and expense, of making prints that don’t match your monitor.
• An efficient digital photography workflow—all of us would prefer to spend more time taking pictures than sitting at the computer making corrections. Most images will need some sort of correction to match your creative vision. Color management helps to eliminate unnecessary corrections caused by moving the photo from one device to another (e.g. switching monitors), or corrections caused by moving from one medium to another (e.g. preparing to print).
• Confidence in sending files to others—if you’re a professional or semi-pro photographer, you need to be confident knowing the picture you deliver to a lab or send to your client will print the way you saw it on screen. There’s nothing worse than an unhappy bride calling to complain that her skin tone is too red in the prints, or an angry client calling about a magazine ad that reproduced poorly. While color management can’t eliminate all the pitfalls of printing, it does minimize opportunities for error.

With all these positives, is there anything color management can’t do?

The limitations of color management are:

• Cannot fully account for nuances of human color vision—as sophisticated as color management is, it cannot fully account for the complexity of our visual system. Color management sees colors as mathematical absolutes, we see color in context and our perception of color changes with our mood, the lighting and paint color of the room, even the amount of caffeine we’ve had today. Color management works remarkably well, but there are times where our expectations for color management exceeds its capacity and it helps to know where color management is successful and where it fails. For example, color management sees the orange square as the same color in both illustrations while our eyes see the orange surrounded by a dark blue as more vivid than the orange surrounded by a rust-colored square.

  Simultaneous Color 1

  Simultaneous Color 2

• Requires regular maintenance to ensure systems are working the same as when the profile was created—an ICC profile is a snapshot of a device in time. As the color characteristics of a device change through age and wear, the use of a different ink or paper, or a change in settings the original ICC profile will not longer accurately describe the color characteristics of that device. It is important to maintain a color management system by testing the validity of profiles and updating or recreating profiles as necessary. For example, your monitor yellows and dims as it ages changing its ability to display certain colors. You’ll need to reprofile your monitor regularly to ensure your monitor is displaying colors accurately.
• Our color perception is subject to environmental variables, light sources, room color, etc.—take an inkjet print and walk over to an incandescent light (go ahead, I’ll wait). Next, look at the print near a north-facing window then look at it under a fluorescent light. The colors in the print change under each light source. The color and intensity of the light source, along with the color of the paint on the walls in your studio and even the color of the shirt you’re wearing affects your perception of the color in the prints. As you demand a higher degree of color accuracy from your monitor and printer, you’ll need to account for these potential variables in the system to ensure they aren’t negatively impacting your workflow.

This article laid the foundation for your understanding of color management in your digital photography workflow. In future articles, I’ll build upon this foundation to address the specifics of monitor calibration, help you set your color management preferences correctly in popular image processing software applications and help you navigate the myriad options standing in the way between you and a perfect print every time.

In the meantime, I welcome your comments, questions and feedback on this article and your overall experiences with color management in your studio.

More

• Jay’s member page
• Jay’s gallery page
• www.jaykinghorn.com
• Photo.net Digital Photography Workflow series

Color Management Primer by Jay Kinghorn

• Part II: Monitor Profiling
• Part III: Color Settings
• Part IV: Printer Profiling

Add a comment

Notify me of comments