The Critically Important Color and Gamma Calibration Article
This article will explain how to understand and work with Photoshop's Color Management System (CMS), including how to create a custom profile, how to create an ICC profile for a monitor, how to set Photoshop's CMS defaults, how to use the Color Settings dialog box, and much more. It is excerpted from Inside Photoshop CS, by Gary D. Bouton. (Sams, 2004, ISBN: 0672326442).
The Critically Important Color and Gamma Calibration Article - Soft-Proofing, or Seeing Onscreen What an Image Will Look Like When It's Printed (Page 16 of 16 )
Because Adobe's soft-proofing feature is driven by ICC profiles, it is a very good idea to collect ICC profiles for every device you use in your work and for every output device your work will be sent to. Getting your local commercial printers to give you an ICC profile for their press, let alone for their press using the exact paper and ink you want to use, is next to impossible. What is possible is to get ICC profiles for traditional hard- proofing materials, such as Matchprints. Most printers will set up their presses to produce results that match the color of an agreed-upon hard-proof. What is also possible is to obtain the ICC profiles of the wonderful new inkjet printers that many folks are using for short-run printing.
Additionally, you already may have noticed that Adobe and your operating system have gifted you with generic ICC profiles for many proofing devices and conditions, as well as default ICC profiles for standard press conditions. Generic ICC profiles are never as precise as custom-made ICC profiles, which is why we showed you how to create a custom ICC profile for your monitor instead of using the default one. But using generic profiles with a CMS is better than not using any CMS at all. So hop on the Web, go to the manufacturers of the equipment you and your customers use, and download the profiles for the devices. It is worth your while to collect ICC profiles for some of the more popular inkjet printers made by Epson, HP, and others. If you don't own one of these printers now, you really should put it on your wish list. Install the profiles, and then move on to the next example.
Note -Printer profiles and paper color
Most ICC printer profiles are based on a specific paper color, generally a neutral bright white.
Soft-Proofing and Color-Correcting an Image
Vision.tif should still be open in Photoshop's workspace. In the last example, we converted the profile associated with the image from Adobe RGB (1998) to sRGB IEC61966-2.1, and then used the Undo command to cancel the conversion of the data and the assignment of a new working profile.
Choose Window, Arrange, New Window for Vision.tif. A new window opens containing an additional view of the original image, not a new copy of the image. Arrange the two image windows so you can see each image.
Choose View, Proof Setup, Custom. In the Profile drop-down list, choose the profile for the inkjet printer you have installed. In the Intent drop-down list, leave the entry as Perceptual, check Use Black Point Compensation, and check Simulate: Paper White, as shown in Figure 2.13. Click OK.
Insider - If you don't have any inkjet or other desktop color printer profiles installed, use the Euroscale Coated profile.
Figure 2.13 In the Proof Setup dialog box, choose the output device to which you want to print, and Photoshop will display the document more or less as it will print.
Notice that the title bar of the inactive window remains the same but that the active image title bar now reads RGB/Epson Stylus Color 860 (your title bar will read whatever you've loaded as a profile). The Epson Stylus Color 860 part corresponds to the Epson printer picked in step 3 and is your soft-proof view. Your title bar will probably say something different because you chose a different output profile. Notice also that the colors in the RGB/Epson Stylus Color 860 window are duller than in the original RGB window. The data hasn't changed; only your view has. Think of it as looking at the RGB/Epson Stylus Color 860 image with Epson glasses on.
Chances are 100% that the image in the soft-proof window is not everything you hoped it would be. The solution? Edit the image. Because these two windows are different views of the same image, any edits you make will be reflected in both windows. It doesn't matter which window is the active window when you make the edits. To improve this image for printing to the inkjet printer, move on to the next step.
Click the Create new fill or adjustment layer icon at the bottom of the Layers palette (fourth icon from the left). Choose Color Balance from the menu. The Color Balance dialog box appears. Drag it off to one side so you can see the images. Make sure the Preview option is checked.
The neutral background in the soft-proof window shows an unwanted color cast. Because you've most likely chosen a different printer to soft-proof to than we have, you may not have a color cast or it may be different from ours. Make your adjustments to suit your image. For the purposes of this example, we'll report what works according to our setup and what looks good to us.
Insider - Although you have set up and are using the CMS in Photoshop, you should not abandon the use of the Info palette for color feedback (correcting by the numbers). Your experience with your intended target device, combined with the Photoshop CMS, will yield better results than using either CMS or experience/Info palette alone.
Keep your eyes on the soft-proof window; that is the window you want to look good. The problem appears to be mostly in the midtones. Preserve Luminosity should be checked. Drag the Cyan slider toward Red (right) to a value of +7; drag the Magenta slider toward Green (right) to a value of +14; drag the Yellow slider toward Yellow (left) to a value of –3, as shown in Figure 2.14. Click OK.
Insider - Now the soft-proof window doesn't have a color cast, but the original window does. That is okay. An image often looks terrible onscreen but prints beautifully. That happens because the monitor and the printer have different color spaces. If you want good printed output, don't get hung up on how it looks onscreen in the working space. Pay attention to the soft-proof view.
Figure 2.14 Use a Color Balance adjustment layer to remove an unwanted color cast that will develop when the image is printed to the inkjet.
Click the Create new fill or adjustment layer icon at the bottom of the Layers palette. Choose Levels from the menu. The image lacks punch because it doesn't really have a good white or black point. Drag the White point slider to around 226. Drag the Black point slider to around 13, and drag the Midpoint slider left to about 1.14, as shown in Figure 2.15. Click OK.
Figure 2.15 Use a Levels adjustment layer to create a better tonal range.
Take a good look at the preview window. If you like what you see, flatten the image by choosing Flatten Image from the Layers palette menu.
Choose File, Save As. In the File name field, enter Vision for Inkjet. Notice that the image still has the original profile listed in the Color section, and not the inkjet profile you proofed to. That happened because the proof view was a view, and not a conversion of the data to a new color space. You did change data when you edited, but it was changed in the context of the working space, not the proofing space of the inkjet. Click Save.
When it comes time to actually print the image to the inkjet printer to get the results you saw in the proof, you will want to change the data. You can do that by using the Convert to Profile command you experimented with in a previous example, or you can choose to do it as part of the print process. (We'll take a closer look at this route in Chapter 21, "Output," on custom halftone schemes.)
Bear in mind that while it takes fewer steps to specify the conversion from the print dialog boxes, you don't get a chance to preview the different Intent options. Consequently, we recommend that you use the Convert to Profile command to change the data in the image and assign the same profile you used for soft-proofing.
That's it! If you've followed along, you've just joined the ranks of color management specialists. And you probably need to focus on postcards of Hawaii to rest your eyes for a week or so. We realize that you may hold the title of designer a little closer to your heart than that of color management specialist, but it will look great on your résumé. It will signal to all that you are an artist who can produce work that can be counted on to look fabulous in any and every media.
http://www.inkjetmall.com/store/ Inkjetmall.com, a division of the famous Cone Editions Press, is a great place to buy ICC profiles for Epson printers. These profiles not only profile the printer, but also specific paper and ink combinations. The site even offers a few free profiles.
http://search.microsoft.com/ Microsoft has lots of information on color management available, but it is not neatly organized in one place. Your best bet is to do a search on its site, using the keywords "color management" or "ICC profiles."
http://www.praxisoft.com Good information on color management is available on the Praxisoft site. The company also sells a reasonably priced (under $100) program called WiziWYG that can create good custom ICC profiles for your scanner and for printers.
http://www.xrite.com/ X-Rite, Inc., makes all kinds of hardware tools for measuring color and calibrating devices. Most of its solutions are rather high-end, very precise, and geared in price toward large, big-budget operations.
This chapter is from Inside Photoshop CS, by Gary D. Bouton. (Sams, 2004, ISBN: 0672326442). Check it out at your favorite bookstore today. Buy this book now.
DISCLAIMER: The content provided in this article is not warranted or guaranteed by Developer Shed, Inc. The content provided is intended for entertainment and/or educational purposes in order to introduce to the reader key ideas, concepts, and/or product reviews. As such it is incumbent upon the reader to employ real-world tactics for security and implementation of best practices. We are not liable for any negative consequences that may result from implementing any information covered in our articles or tutorials. If this is a hardware review, it is not recommended to open and/or modify your hardware.