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									                                       Getting Four-Color Separations                        659

                                                                                                          Book IX
                                                                                                         Chapter 1




                                                                                                            Prepping Graphics
                                                                                                                 for Print
            Cyan                          Magenta




           Yellow                          Black




                                                Corbis Digital Stock
Figure 1-2: Color images are separated into four process colors.



   Table 1-3                              Output Options
  Option              What It Does                                     Recommendation
  Calibration         Prints an 11-step grayscale bar out-             Select this option.
  Bars                side the image area to gauge how
                      accurately the shades are being
                      printed. When you’re printing sepa-
                      rations, this option prints a gradient
                      tint bar and color bar.
  Registration        Prints crosshair and target marks                Select this option.
  Marks               outside the image area, allowing you
                      to line up the four plates or pages.
                                                                                             continued
660   Creating Spot Color Separations



            Table 1-3 (continued)
           Option            What It Does                              Recommendation
           Corner Crop       Adds crop marks at the corners of         Select this option.
           Marks             the image to indicate where to trim
                             the image.
           Center Crop       Adds crop marks at the center of          Select this option.
           Marks             each side of the image to indicate
                             where to trim the image.
           Description       Prints the description as entered in      Select if you have
                             the File➪File Info area.                  entered a description.
           Labels            Prints the filename and channel           Select this option.
                             name on each plate or page.
           Emulsion          Emulsion is the side of the film that’s   Leave this option dese-
           Down              light sensitive. Allows the film to       lected for laser separa-
                             be printed with the emulsion side         tions. When the service
                             down.                                     bureau or offset printer
                                                                       prints the separations
                                                                       to film or plates, it may
                                                                       select this option.
           Negative          Prints black as white and white as        Leave this option dese-
                             black, and every other color inverts      lected for laser separa-
                             accordingly.                              tions. When the service
                                                                       bureau or offset printer
                                                                       prints the separations
                                                                       to film or plates, it may
                                                                       select this option.
           Interpolation     Anti-aliases low-resolution images        Available only for
                             by resampling.                            PostScript Level 2 or
                                                                       laser printers. Leave it
                                                                       deselected.
           Include           See the “Saving and Printing Vector       Leave this option
           Vector Data       Data in a Raster File” section, in this   selected if you have type
                             chapter.                                  or vector paths.



Creating Spot Color Separations
         Photoshop allows you to add separate channels for spot colors (see Book VI,
         Chapter 1, for more on channels), which can then be color-separated. Spot,
         or custom, colors are premixed inks manufactured by various ink companies,
         the most popular in the U.S. being Pantone. A spot color is often used for a
         logo, type, or small illustration. Spot colors are also used when you need to
                                Creating Spot Color Separations               661

apply metallic inks or varnishes to your print job. Spot colors can be used               Book IX
rather than, or in addition to, the four process CMYK colors.                            Chapter 1

If you’re delving into the world of spot colors, I highly recommend that




                                                                                            Prepping Graphics
you choose your color from a printed Pantone swatch book, available from




                                                                                                 for Print
www.pantone.com. Because your screen is an RGB device and you’re set-
ting up your file for a CMYK output device, the colors you see onscreen
don’t match the colors that are ultimately on paper — at best, they’re a
ballpark match. For accuracy, you must select the colors from the printed
swatch book. For more on working with color, see Book II, Chapter 3.


Creating a spot channel
Follow these steps to create a spot channel:

 1. On a separate layer, create the graphic or type to which you want to
    apply the spot color.
 2. Ctrl-click (Ô-click on the Mac) the thumbnail of the layer to select the
    graphic and then choose Edit➪Fill to fill it with any solid color at an
    opacity of 100 percent.
 3. With your selection active, choose
    Window➪Channels and then
    select New Spot Channel from the
    Channels panel pop-up menu.
    You can apply a spot color only to
    an active selection. It can’t be
    applied to just a layer.              Figure 1-3: Adding an additional color
                                          separation in Photoshop requires creating a
    The New Spot Channel dialog box       spot color channel first.
    appears, as shown in Figure 1-3.
 4. In the Name text box, enter a name for your spot color. In the Ink
    Characteristics area, click the color swatch.
    I recommend naming your
    spot color according to the spot
    color you want to use, such as
    Pantone 7417C.
    When you click the color swatch,
    the Color Picker appears.
 5. Click the Color Libraries button in
    the Color Picker and select your
    Pantone color from the Color
    Libraries dialog box that appears     Figure 1-4: Select an appropriate color from
    (see Figure1-4), and then click OK.   the Color Libraries dialog box.
662   Creating Spot Color Separations


          6. In the New Spot Channel dialog box, select a
             Solidity value between 0 percent and 100
             percent.
             A value of 100 percent represents an ink that’s
             completely opaque, such as a metallic ink,
             which completely covers the inks beneath it.
             A value of 0 percent represents a transparent
             ink, such as a clear varnish. But the solidity
             value affects only the screen view and com-
             posite prints; it doesn’t affect the separations.
             It can help you see where a “clear” varnish
             will print.                                       Figure 1-5: The Channels panel
                                                                       displays the spot channel.
          7. Click OK to close the dialog box.
             Your spot channel appears in the
             Channels panel and is filled in the
             image, as well. I created a spot
             channel for my crest graphic and
             for the type (Pantone 7417C), as
             shown in Figure 1-5.
             In the printing process, spot colors
             are overprinted on top of the four-
             color image, as shown in Figure
             1-6. That means that the spot color
             is applied at the end of the printing
             process and is printed over the
             other inks. This can sometimes
             cause lighter spot colors to darken
             somewhat.
             If you need your spot color graphic
             to knock out the underlying image,
             create it in an illustration or page
             layout program. A knockout is a
             hole left in the four-color image,
             which is filled with the spot ink.                                   Corbis Digital Stock
             The spot ink doesn’t print over the
             other inks.                          Figure 1-6: Spot colors are often used for
                                                         color-critical logos that print on top of
          8. Save the image in the native      your image.
             Photoshop, Photoshop PDF, or
             Photoshop DCS 2.0 (Desktop Color Separations) format.
             TIFFs also support spot channels, but your page layout program may
             not recognize them.
                                                   Creating Spot Color Separations              663

                If the image is being separated directly out of Photoshop, leave it as a                  Book IX
                PSD or PDF file. If you want to import it into a different program, such as              Chapter 1
                InDesign, or QuarkXPress, you must save it as a DCS file. If your image is
                a duotone, tritone, or quadtone image, you also have to go through a few




                                                                                                            Prepping Graphics
                more hoops. You must first convert it to multichannel mode by choos-




                                                                                                                 for Print
                ing Image➪Mode.
                In the DCS 2.0 Format dialog box, make sure that the Include Halftone
                Screen and Include Transfer options aren’t selected.
                Import the image into your destination application and set your screen
                angles.


           Editing a spot channel
           After you create a spot channel, you can edit it. Select the channel in the
           Channels panel and use a painting or editing tool to paint with black, white,
           or any shade of gray, just as you would with an alpha channel. To change
           any of the options of the spot channel, double-click the spot channel thumb-
           nail, or select it and then select Channel Options from the panel pop-up
           menu. Select a different color or solidity.




   Converting an alpha channel to a spot channel
If you want to convert an alpha channel to a        all areas containing nonwhite pixels (unselect-
spot channel, select the alpha channel in the       ed to partially selected areas) to the spot color.
Channels panel and select Channel Options           With the channel still selected in the Channels
from the panel’s pop-up menu. Rename the            panel, choose Image➪Adjustments➪Invert to
channel and select Spot Color. Click the color      apply the spot color to the white pixels or se-
swatch and select a color from the Color Librar-    lected areas of the alpha channel. For details
ies section of the Color Picker. Click OK, then     on alpha channels, see Book VI, Chapters 1
click OK again. Note that Photoshop converts        and 3.
664   Book IX: Photoshop and Print
      Chapter 2: Using Photomerge
      and Merge to HDR Pro
      In This Chapter
      ✓ Creating a panorama from multiple shots
      ✓ Merging photos for superior quality



      S    ometimes, working with just a single shot isn’t quite enough. You
           couldn’t quite squeeze that beautiful mountain vista into one photo; it
      took three shots. Not to worry, that’s what Photoshop’s Photomerge com-
      mand is for. This great command seamlessly stitches multiple shots of your
      panorama into a single image. Similarly, trying to capture the entire tonal
      range of an image can be tough. The Merge to HDR Pro command enables
      you to take multiple exposures of an image and later merge those exposures
      into a single High Dynamic Range image, allowing for superior image quality.
      And as if that alone isn’t enough, these two commands are found on
      Photoshop’s Automate menu, meaning they’re quite easy to use.



Using the Photomerge Command
      The Photomerge command allows you to combine multiple
      images into one continuous panoramic image. For exam-
      ple, you can take several overlapping photos of a
      mountain range and put them together into one pan-
      oramic shot using the Photomerge dialog box, as
      shown in Figure 2-1.

      If you know you ultimately want to create a
      Photomerge composition, you can make things eas-
      ier by making sure that when you shoot your pho-
      tos, you overlap your individual images by 15 to 40
      percent, but no more than 70 percent. Adobe also rec-
      ommends that you avoid using distortion lenses (such
      as fish-eye) and your camera’s zoom setting. Finally, try to
      stay in the same position and keep your camera at the same
      level for each shot. Using a tripod and rotating the head can help
      you achieve this consistency. If you are lucky enough to have a nice, long
      parallel surface handy (like a sidewalk), try taking spaced photos using your
      tripod along this surface.
666   Using the Photomerge Command




                                                                       Photodisc
         Figure 2-1: Select several overlapping shots to create one panoramic image.


         Follow these steps to assemble your own Photomerge composition:

          1. Choose File➪Automate➪Photomerge.
             You can also select your desired source images and choose Tools➪
             Photoshop➪Photomerge in Adobe Bridge. Using Bridge is a timesaver
             because you can quickly and visually select your images.
          2. In the Photomerge dialog box, shown in Figure 2-1, select your
             source files.
             From the Use pop-up menu, you can select from Files (which uses indi-
             vidual files you select) or from Folder (which uses all images in a folder.
             Click the Add Open Files button to use all currently open files. Or click
             the Browse button to navigate to your desired files or folder.
             If you want to delete a file from the list, select it and click Remove.
          3. Select Blend Images Together to correct the color differences that can
             occur from blending images with different exposures.
             Photoshop then blends the colors and tones.
             If the Blend Images Together option doesn’t help, you can always create
             a blending group. First, in your Layers panel, create a new group con-
             taining the layer you want to change. Next, change the group Blend
             mode to Normal. Finally, add an adjustment layer, such as Levels or
             Exposure, in the group above the layer you want to change. For more on
                               Using the Photomerge Command              667

    adjustment layers, see Book V, Chapter 1. For more on blend modes, see        Book IX
    Book V, Chapter 3.                                                           Chapter 2
 4. Select Vignette Removal to correct exposure problems caused by lens




                                                                                 Using Photomerge
    vignetting (when light at the edges of images is reduced and therefore




                                                                                    and Merge
                                                                                    to HDR Pro
    edges are darkened).
 5. Select Geometric Distortion Correction to correct for lens distortions,
    such as radial distortion, barrel distortion (bulging out), and pincush-
    ion distortion (pinching in).
    You can use this option to align shots taken with a fish-eye lens.
 6. In the Layout area, select your desired project mode, as shown in
    Figure 2-1.
    The thumbnail illustration visually demonstrates each mode, but I’ll give
    you a little more description of each:
     • Auto: Select the Auto mode to make Photoshop analyze your images
       on its own.
     • Perspective: Select this mode if your images have been shot with per-
       spective, or at acute angles. This mode is also recommended for
       High Dynamic Range (HDR) images.
     • Cylindrical: Select this option if you shot your images with a wide-
       angle lens or when your images have that nasty “bow-tie” distortion.
       This mode is also good for those 360-degree, full panoramic shots.
     • Spherical: This mode is handy when stitching together a 360-degree
       panorama, in which you have a wide field of view, both horizontally
       and vertically. Use this option for shots taken with a wide-angle lens.
     • Collage: This projection method aligns images by rotating, position-
       ing, and uniformly scaling each image. It may be the best choice for
       pure panoramas, but you can also find it useful for stitching together
       images based on common features.
     • Reposition: When you select this mode, Photoshop doesn’t take into
       account any distortion, but merely scans the images and positions
       them in what it considers the best position.
 7. Click OK.
    Photoshop marches off and attempts to automatically align and “stitch”
    your source images into a new Photoshop image, shown in Figure 2-2.
    Hopefully, all goes well; however, if Photoshop can’t align and merge, it
    presents an alert that says “some images could not be aligned.”

No matter which projection mode you select, Photoshop leaves your merged
image in layers. In addition to those layers, Photoshop may also add a layer
mask to each layer to better blend and composite your merged image. These
layer masks act like any other layer masks, meaning you can edit them to
your liking. For more on layer masks, see Book VI, Chapter 3.
668     Using the Merge to HDR Pro Command




                                                                                                Photodisc

Figure 2-2: The Photomerge command enables you to combine multiple images into one continuous
panoramic shot.



Using the Merge to HDR Pro Command
             Have you ever caught an early matinee and emerged molelike from the
             pitch-black theater into the bright light of high noon, only to have to squint
             for a while because your eyes burned? Or on the flip side, have you blindly
             tumbled into your seat, popcorn scattering all over the aisle in that same
             darkened theater because you just came in from the bright daylight? In
             both cases, your eyes needed some time to adjust to the abrupt change
             from extreme dark to extreme light or vice versa. Cameras suffer from the
             same problem. But although our eyes can eventually adapt to varying
             brightness levels, cameras and devices, such as computer monitors and
             scanners, can capture only a fixed dynamic, or tonal, range. In digital imag-
             ing tech talk, dynamic range is the ratio of the darkest and brightest values
             a device can capture simultaneously.

             In the past, digital photography aficionados were hindered when performing
             higher-end, image-editing tasks in Photoshop because they were forced to
             work within a limited dynamic range. Recent versions of Photoshop have
             provided users with plenty of support for High Dynamic Range (HDR) images.
             HDR images, which contain 32 bits of data per channel, are superior to non-
             HDR images because they can capture a much larger dynamic range — in fact,
             they’re able to represent the entire dynamic range of the real world.

             Photographers can take multiple exposures of an image and then later merge
             those multiple exposures into a single photo in Photoshop, thereby captur-
             ing the entire dynamic range into a single HDR image. Although you can use
             the Merge to HDR Pro command on 8- or 16-bit images, be aware that only
             32-bit images can store all the HDR data.

								
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