B Color Calibration

All photographers are concerned with accurate and pleasing color rendition, be it on monitors or in prints; and there may be no more critical audience, in more than one sense, than the wedding couple and their circle of friends and family. You want your work to look its absolute best, whether you are presenting the Proofing Show on your laptop, showing the crown jewel of your work—the wedding album—or even running a quick slideshow of pleasing pictures taken earlier, at the reception. As with everything else connected with digital photogra- phy, this does not happen by magic. As usual, a bit of technical knowledge is nec- essary, along with some preparation with your monitor, and perhaps your camera and scanner as well, using some tools and tests to tune your devices so that the colors you display closely match each other, and look good doing it. We’ll explain the necessity in relatively painless technical terms, then present effective tools and procedures for calibrating your equipment, including important tips, advice on choosing appropriate equipment, and links to further information all the way out to the physics of light and color for adventurous readers.

Did You Notice That Red Light? If you have ever heard that question, you might carefully consider asking politely about yellow or green, but you would probably not ask, “What do you mean by ‘red’?” Color, however, is a slippery concept, except when physicists speak in terms of the length of light waves, and even then there are arbitrary divisions and nam- ing conventions. South sea islanders have scores of different words for the “blue- green color” of the sea; and people living around the Arctic Circle have a great and extensive vocabulary for the color and condition of “snow.” Our first step will be 2 Mastering Digital Wedding Photography defining what digital photographers need to consider practically about color and the use of their equipment to produce consistent, and consistently pleasing, color output.

Note

Much of the following information has been provided by DisplayMate Technologies Corporation, the makers of the leading and definitive software pro- gram, DisplayMate. This program has been the pioneer and leader in the produc- tion of color-calibration software technology. DisplayMate is the choice of scores of leading manufacturers, labs, and industry publications. We appreciate permission to use their information. You can learn a great deal more about color and calibra- tion matters at their website, www.displaymate.com, as well as read about several versions of DisplayMate and download trial versions. Much of what follows is excerpted from their website to give you an appreciation of the complexity of the subject and an overview of basic procedures.

The Spectrum of Testing Obviously, in this book we are assuming you’re using digital cameras; monitors can be either analog (the familiar CRT) or digital (the now-familiar LCD and plasma screens), printers are analog, and scanners convert analog images to digi- tal files. And of course the computer at the center of all these devices is a digital device with a videocard with its own color outputs and adjustments. Where do we start? With the calibration of the specific type, make, and model of monitor with the particular video output of the particular computer system. DisplayMate has a complete series of test screens to adjust your components and calibrate them. This step is fundamental to knowing that your evaluation of the hue, saturation, sharpness, etc., of your digital images is accurate enough to serve as a starting point. Calibrating your printer is a good idea, even if you are plan- ning to send your printing work to a lab. It’s a good idea in general, and if you want to make a few test prints, it’s absolutely necessary to get the printer output as consistent with the digital images and your display as possible. You may not know it, but you can further calibrate your components with the output of your digital camera itself. DisplayMate allows you to do this, after you have done the preceding calibrations. Finally, if you are scanning prints or negatives to use in your albums or slideshows, you will need to calibrate your scanner as well. Once you have done these procedures, you should not have to do them very frequently, unless near-perfect calibration on high-quality equipment is necessary for a top- drawer project. Appendix B ■ Color Calibration 3

First: Set Up Your Display The first step is to properly calibrate your display because it’s your working visual reference. Initially, this needs to be done independently of the printer. 1. Set up your display for optimum image and picture quality using DisplayMate. 2. Step through each DisplayMate test pattern and follow the on-screen instruc- tions that explain what to look for in the image and what adjustments to make. 3. Be sure to use all of the display and video board controls available on your system. Carefully read your display and video board documentation for infor- mation on accessing and adjusting each of the controls. 4. If your video board includes a “Gamma” control, set it to 1.0 (linear) so that it is not affecting the image at this stage. Note: This leaves the display’s own internal Gamma in effect. 5. Set the color temperature of the display to 6500° Kelvin, which is Daylight White. Color temperatures of 3000° to 5000° are used in many photographic and graphics arts applications, but start out with 6500°, which is the standard for video. Note: Most displays come from the factory set for 9300° Kelvin, which produces a brighter but bluer image. Be sure to record all the initial and final settings so you can recall and restore them later.

The Monitor versus the Printer Getting the display and printer to produce consistent color so that what you see on the display is what you get on the printer turns out to be a surprisingly diffi- cult process. One reason is that the eye and brain are very sensitive and discrimi- nating to subtle differences in color and intensity. Color reproduction involves the interaction of many complex parameters, each of which must be carefully accounted for and calibrated. The technologies involved are also very different, and they give rise to significant differences in reproduction: ■ The display has a much broader color gamut than the printer, so there are col- ors that can be displayed on your monitor that can not be accurately printed. ■ The display uses additive RGB colored light given off by phosphors or filters, whereas the printed output uses subtractive absorption of the light reflected off the paper through CMYK pigments. ■ The display has greater color saturation, dynamic range and contrast. Printed images generally appear darker and duller. ■ The texture and brightness of the paper are also important factors. 4 Mastering Digital Wedding Photography

Printing is inherently non-linear because of the layering and overlapping of the different inks and variations in the relative positions, sizes, and profiles of the ink dots.

Updating the Printer Driver Colors are processed through a series of software layers on the way to being printed. These include the printer driver, color management software (if any), and your image processing program (such as Adobe Photoshop). The best way to pro- ceed is to systematically turn on one layer at a time so that you’re sure that each layer is improving rather than degrading the image. If you are using the printer driver that came installed with Windows instead of the custom driver that came with your printer, then you are probably missing important advanced controls provided by the printer’s manufacturer. Those addi- tional controls should simplify and improve the printer’s calibration. So the first step is to make sure that you have installed the custom driver for your printer. To check, go to the Control Panel and select Printers. Right-click on desired printer and select Properties. Look through all of the tabs, paying partic- ular attention to ones that say Color or Advanced. Look for controls like Ink Density, Color, Saturation, Brightness, and Contrast. Details will vary with the manufacturer and model. If you haven’t installed the proper driver, then find the CD that came with the printer and install it. If you can’t find the CD, then go to the manufacturer’s website and download it. If you are especially motivated, the next step is to check for driver updates. It’s very important to get the latest and most advanced drivers for all of your image devices, particularly the video board and printer. ■ Go to each manufacturer’s website and search for updated drivers and docu- mentation. ■ Check to see if there are enhanced versions of the drivers with advanced fea- tures or controls that are not available or accessible with the standard drivers. These are not necessarily beta versions but rather have additional functional- ity for advanced users or users with special needs. ■ Scan the manufacturer’s website for information on activating “hidden” fea- tures or controls in the drivers. ■ Contact the manufacturer’s Technical Support and ask for additional infor- mation. ■ Check user groups and websites for unofficial information and enhancements. Exercise caution in making use of any unofficial information or software you obtain in this way. Appendix B ■ Color Calibration 5

Setting Up the Printer Baseline The first step is to set up your printer without introducing any effects from your color management or image processing software (such as Adobe Photoshop). We will bypass them now and then introduce them one at a time later on. Set all of the printer and printer driver controls to their factory defaults and turn off any Color Management profiles or software. This is generally done through Printer Properties. Examine each of the tabs for the appropriate controls settings. To begin the calibration process, follow the instructions in step 7 using the avail- able controls in the printer driver.

Print and Compare the Test Patterns For this step we recommend that you use the Microsoft Paint program, which is included in all versions of Windows. This is a very simple program, and we want to make sure that the test pattern images are not altered or processed in any way. 1. First, reduce the screen resolution in order to reduce the size of the printed test patterns. Also start off by using inexpensive copy paper and print at draft speed. This will cut down on ink usage and speed things up. As you get closer to a satisfactory calibration, upgrade the paper, image size, and print quality. 2. You are going to print selected DisplayMate test pattern images and then com- pare them to the monitor. You can use a wide selection of DisplayMate test patterns, but the following patterns will be useful for most users and applica- tions: Color Scales, Color Triangle, Color Spectrum, Color Blend, Pastel Blend, Standard Colors, Extreme Grayscale, and 16 Intensity Levels. 3. This is an iterative process, particularly when there are multiple adjustments that interact. Document the print settings you’ve used on each printed out- put page. 4. Repeat the above procedure until no further improvements are possible. 5. Be sure to record all of the settings so you can recall and restore them later. Printer color fidelity should now be improved.

Optional: Adjusting Color Management Software An advanced color management system is, in principle, the Holy Grail for accu- rate color reproduction among imaging devices such as displays, printers, scan- ners, cameras, etc. It is supposed to accurately transform and map all of the colors so they automatically appear the same on all the imaging devices in your system. Because printing, in particular, is a non-linear process, the accuracy will depend 6 Mastering Digital Wedding Photography on the sophistication of the color management algorithms and how well they were calibrated by the manufacturer. The best of these systems are very complex and expensive. In practice, many color management implementations do not work particularly well and may even degrade rather than improve color accuracy. Not all systems include color management. If yours does then we will figure out in this step whether you should leave it on or turn it off. If your printer driver and optional color management haven’t provided the desired color accuracy, then you’ll need to take advantage of the controls available in an image processing program. Adobe Photoshop is the most comprehensive and pow- erful of these, but even inexpensive programs generally provide many sophisti- cated adjustment tools to calibrate, correct, and manipulate color hue, saturation and balance, brightness and contrast, grayscale, Gamma, etc. Some calibration tools will apply to the monitor and others to the printer.

Optional: Adjusting the Monitor to the Printer We’ve now calibrated the printer as far as we can. The next step is to reverse the calibration procedure and readjust (actually misadjust) the monitor so that it looks as close as possible to the final calibrated printer output. Compare the printed DisplayMate test patterns to those on the display. ■ Adjust the display Brightness Control to match the dark-end (shadows) of the intensity scale. ■ Adjust the display Contrast Control to match the bright-end (highlights) of the intensity scale. In most cases, decreasing the display Contrast will improve the match. ■ Adjust the video board Gamma control (if available—see Advanced Settings of Display Properties) to match the middle (midtones) of the intensity scale. This will also affect the midtone colors as well. Note: This control is partic- ularly important for a good color and intensity scale match. ■ Adjust the display Color Temperature control to give the best match for the color of white and the best overall color tone and balance. ■ If your display includes RGB Drive or RGB Gain controls, then further refine the Color Temperature adjustment for the best overall color tone and balance. ■ Be sure to record all the settings so you can recall and restore them later. DisplayMate also includes instructions on how to calibrate the scanner at this point. Appendix B ■ Color Calibration 7

Award-Winning Hardware The equipment listed in DisplayMate’s Best Video Hardware Guide™ is in DisplayMate’s judgment the best commercially available video hardware in each of 50 Award Categories. The awards are based solely on image and picture qual- ity excellence and are recommended as a comparative standard of excellence for consumers, corporate buyers, reviewers, test labs, and manufacturers alike.

About the Guide www.displaymate.com/best.html The Guide is the most comprehensive and complete listing of outstanding video display hardware available worldwide. It is produced by DisplayMate Tech- nologies, which is recognized as the foremost source for testing and evaluation of image and picture quality throughout the computer and video industries world- wide. DisplayMate is an industry standard used for judging major international industry events. Over 200 publications in 50 countries use DisplayMate for their editorial testing and lab reviews of video hardware. The Guide is an objective and free service of DisplayMate Technologies. Manufacturers do not pay anything to appear in this Guide. All of the video hardware is tested and evaluated by DisplayMate Technologies Labs. Awards are based on the accurate reproduction of DisplayMate’s most challenging test patterns using the DisplayMate Multimedia Edition.

Model Availability Almost all of the products listed are currently available through standard retail channels. A number of products, particularly CRTs, are no longer readily avail- able. They are still listed because we have not found suitable replacements. You may find them by looking through old inventory or on eBay.

Display Technology Shoot-Out

Comparison of CRT, LCD, Plasma, DLP, and LCoS Technologies This is a link to a rigorous technical survey of available display technologies. Used by permission of DisplayMate Technologies, Inc. www.displaymate.com/ShootOut_Comparison.htm 8 Mastering Digital Wedding Photography

Color Basics and Color Accuracy This is a link to an excellent article on the basics of color theory and accuracy, including such concepts as the color spectrum, grayscales, color gamut, Gamma, and standard color controls on equipment. Used by permission of DisplayMate Technologies, Inc. www.displaymate.com/ShootOut_Part_2.htm

Digital Photography Tutorials This is a link to an excellent collection of short tutorials on digital photography, including many useful ones on color. www.cambridgeincolour.com/tutorials.htm