Real World Adobe Photoshop CS Industrial Strength Production Techniques

Transcription

1 Excerpted from Real World Adobe Photoshop CS Industrial Strength Production Techniques David Blatner Bruce Fraser

2 Chapter 9: The Digital Darkroom 463 Making Prints The digital darkroom wouldn t be worthy of the name if it didn t let you make prints. Fortunately, it not only does so, but also offers a key advantage over its analog counterpart: Thanks to the wonders of color management, it lets you see what will happen in the print before you make it. The naive view of color management is that it will make your prints match your monitor. If you ve read this far, you ve probably realized that this is an impossible goal printers simply cannot print the range of color a good display can display. Instead, color management tries to reproduce the image as faithfully as the limitations of the output process will allow. But color management knows nothing about images, it only knows about the color spaces in which images reside. So no output profile, however good it is, does equal justice to all images. When you convert an image from a working space to the gamut and dynamic range of a composite printer, the profile treats all images identically, using the same gamut and dynamic range compression for all. But thanks to the soft-proofing features in Photoshop, you can see ahead of time exactly how the profile will render your images, which gives you a good basis for taking the necessary corrective action. If you want great, rather than just good, you need to optimize images for different output processes, because something always has to give, and each image demands its own compromises.

3 464 Real World Adobe Photoshop CS Adjustment layers provide a very convenient method for targeting images for a specific output process. You can use adjustment layers grouped in layer sets to optimize the same master image for printing to different printers, or to the same printer on different paper stocks. The following technique uses three basic elements. A reference image. Create a duplicate of the image, with Proof Colors turned off, to serve as a reference for the image appearance you re trying to achieve. A soft proof. Use the Proof Setup command to provide a soft proof that shows how the output profile will render the image. A layer set containing adjustment layers. Group each set of optimizations for a specific output condition (printer, paper, ink) into a layer set, so that you can turn them on and off conveniently when you print to one or another device. Making the reference image. Choose Duplicate from the Image menu to make a duplicate of the image. The duplicate will serve as a reference for the appearance you re trying to achieve on the print. You need to make a duplicate rather than simply open a new view because you ll be editing the master image to optimize it for the print, and the edits would show up in a new view. The duplicate isn t affected by the edits you make to the master file, so it can serve as a reference a reminder of what you want to achieve in the print. Setting the soft proof. Choose Custom from the Proof Setup submenu on the View menu to open the Proof Setup dialog box. Load the profile for your printer, and check Paper White to make Photoshop use absolute colorimetric rendering to the monitor (see Figure 9-39). We find that all the soft-proof views (using the different combinations of Paper White and Ink Black) tell us something useful, but the absolute colorimetric rendering produced by checking Paper White is, in theory at least, the most accurate. However, the first thing you ll notice is that checking Paper White makes the image look much worse. Sometimes it seems to die before your eyes. At this point, a good many people think Photoshop s soft proof must be inherently unreliable and give up on the whole enterprise. What s really

4 Chapter 9: The Digital Darkroom 465 Figure 9-39 Setting the soft proof Load the profile for your output device, and check Paper White. going on is that Photoshop is trying to show you the dynamic range compression and gamut compression that will take place on printing. The reason the soft proof looks bad at first glance is that Photoshop can only show you the gamut and dynamic range compression within the confines of your monitor space, and it can only do so by turning things down, so white in the image is always dimmer than your monitor white. A second problem is that the vast majority of monitor profiles have a black hole black point (a black with a Lightness of zero in Lab), while real monitor black typically has a Lightness of 3 to 5. As a result, the soft proof typically shows black as slightly lighter than it will actually appear on the print. Typically, in the soft proof you ll see washed-out shadows, compressed highlights, and an overall color shift caused by the difference between the white of your working space and the white of your paper. Some images are only slightly affected by the conversion to print space, while with others the change can be dramatic, as shown in Figures 9-40a and 9-40b. As with just about any proofing method we ve encountered, you need to learn to interpret Photoshop s soft proofs. You may find the following tips helpful in doing so. Tip: Look Away When You Turn On Paper White. Much of the shock you feel when you see Photoshop s absolute colorimetric rendering to the monitor stems from seeing the image change. If you look away from the monitor when you turn on Paper White, your eyes will be able to adapt to the new white point more easily. Tip: Use Full-Screen View to Evaluate Soft Proofs. Your eyes can t adapt to the soft-proof white point unless you hide Photoshop s user interface elements, a good few of which are still pure white. Press F to switch to full-screen view with a neutral gray background, then press Shift-F to

5 466 Real World Adobe Photoshop CS Figure 9-40a The soft proof and the reference image The soft proof, left, shows reduced contrast and a slight blue shift when compared to the reference image, below. hide the menu bar. Press Tab to hide all the palettes. Now you can see the soft-proofed image on a neutral background with no distracting elements to bias your vision. A further problem, one we hope proves to be temporary, is that many output profiles weren t built with soft-proofing in mind. They do a good job of converting the source to the output, but they don t do nearly as good a job of round-tripping converting the output back to a viewing profile. All the profiles we ve built with current third-party profiling tools make the round trip very well. The problem seems confined to older profiles, and to some, but by no means all, of the canned profiles that printer vendors include with their printers. If all this seems discouraging, take heart. Soft-proofing for RGB output may have passed its infancy, but it hasn t yet reached adolescence. And problems with profiles aside, the soft proofs offered by Photoshop are not, in our experience, any less accurate than those offered by traditional proofing systems. You simply need to learn to read them.

6 Chapter 9: The Digital Darkroom 467 Figure 9-40b The soft proof and the reference image, continued The soft proof, left, shows a dramatic color shift in addition to the reduced dynamic range when compared with the reference image, right. Make your edits. We suggest starting out viewing the soft proof and the reference image side-by-side. Once you ve edited the soft-proofed image to get it back to where you want it to be, fine-tune your edits looking at the soft-proofed image in full-screen view. Some images need minimal editing, others may require significant reworking. We start by applying adjustment layers to get the soft-proofed image to match the reference (the duplicate) as closely as possible. We group these adjustment layers in a layer set named for the print process it addresses. That way, we can easily optimize the master image for different print processes by turning the layer sets on and off. Figure 9-41 shows the edited and reference images with their accompanying layer sets. Once we ve edited the soft-proofed image to match the reference image, we use full-screen view to take a final look at the soft-proofed image prior to printing. (We prefer the gray background, with the menu bar hidden the black background makes the shadows look too light.) In the majority of cases we find that no further editing is necessary, but occasionally we ll fine-tune highlight and shadow detail. The final step is, of course, to print the image. See Imaging from Photoshop in Chapter 17, Output Methods.

7 468 Real World Adobe Photoshop CS Figure 9-41 The edited image and the reference image We edited the soft-proofed image, above, to match the reference image, below. The RGB curve restores contrast. The blue curve removes the blue cast. The Hue/Saturation layer shifts the blue of the sky slightly toward magenta.

8 Chapter 9: The Digital Darkroom 469 Figure 9-41 The edited image and the reference image, continued The Curves adjustment layer adds contrast using the RGB curve. We added small amounts of red and green, and reduced blue, to remove the color cast in the sky and on the building.