Photoshop 6 for Windows Bible- P23 pot

631 Chapter 13 ✦ The Wonders of Blend Modes If you want all layers in the clipping group to blend as a unit, select the Blend Clipped Layers as Group check box (it’s at the bottom of the spotlighted area in Figure 13-16). If you selected different blend modes for the individual layers in the clipping group, Photoshop uses the mode applied to the base layer for all layers. To adjust blending of the base layer only, deselect the check box. Now all blending options except the Opacity slider have no impact on any layer in the clipping group except the base layer. Blending individual color channels Directly underneath the Fill Opacity slider, the Channels check boxes enable you to blend color channels independently of each other. (When you’re working on a grayscale image, this option is unavailable because the image has only one chan- nel.) For some examples of the creative possibilities afforded by the Channels fea- ture, see Color Plate 13-5. Knocking out layers The Knockout pop-up menu is another of the blending options new to Photoshop 6. It turns the contents of the active layer into a floating hole that can bore through one or more layers. You specify how deep the hole goes using the Knockout option; use Opacity and blend mode options to define the translucency of the hole. Select a Knockout option depending on what layers you want to blend together: ✦ None blends normally. The layer is treated as a standard layer, not a hole. ✦ Shallow cuts a hole through a layer set to expose the layer immediately below the layer set. In a clipping group, Shallow burrows down to the base layer of the group. ✦ Deep cuts all the way down to the Background layer. An exception arises when you’re working with a layer in a clipping group. In that case, Deep blends the layer with the base of the clipping group, just like Shallow. Figure 13-18 shows examples of each of these options. In all the examples, the top layer contains black text, to which I applied the Outer Glow and Bevel and Emboss layer effects. The next layer down holds an umbrella and a few associated layer effects. I grouped these two layers into a layer set, as shown in the Layers palette in the figure. The clouds occupy the layer immediately below the layer set. The back- ground layer contains a gradient created with the new noise-gradient feature (see Chapter 6). In the upper-left example, I set the Knockout option to None for all layers. I used the Normal blend mode and set the Opacity value and Fill Opacity value to 100 percent throughout. With this setup, each layer blends normally with the one below. 6 Photoshop 6 6 Photoshop 6 632 Part IV ✦ Layers, Objects, and Text Figure 13-18: Here you see how the original image (top left) appears after I lowered the opacity of the text layer to 25 percent and then applied each of the three Knockout options. To create the top-right image, I lowered the Fill Opacity value for the text layer to 25 percent and left the Knockout setting at None. You see the pattern of the umbrella through the faded text, as you would expect. The effects (Outer Glow and Bevel and Emboss) remain unchanged because they lie beyond the bounds of the filled portion of the layer and thus don’t respond to the Fill Opacity slider. For the bottom-left example, I left the Fill Opacity at 25 percent but set the Knockout option to Shallow. Now the text interior blends with the cloud layer, which is the layer immediately beneath the layer set that contains the text. For the final example, I selected Deep from the Knockout pop-up menu, blending the text interior with 25% Fill Opacity, NoneOriginal 25% Fill Opacity, Deep25% Fill Opacity, Shallow 633 Chapter 13 ✦ The Wonders of Blend Modes background layer and creating the nuclear rain environmentalists have worried about for years. Knocking out by brightness value The Blend If sliders, found at the bottom of the Blending Options panel of the Layer Style dialog box, enable you to drop out pixels in the active layer and force through pixels from lower layers according to their brightness values. When you use the sliders, Photoshop applies your changes taking the Knockout option into account. For example, if you set the Knockout option to Deep, you force through pixels from the Background layer instead of from the layer immediately below the selected layer. Select a color channel from the Blend If pop-up menu to apply the effects of the slider bars beneath the menu to one color channel independently of the others. Each time you select a different Blend If option, the slider triangles change to the positions at which you last set them for that color channel. Select a color channel from the Blend If pop-up menu to apply the effects of the slider bars according to the contents of a single color channel. Choose Gray to base the changes on the grayscale composite. Each time you select a different Blend If option, the slider triangles change to the positions at which you last set them for that color channel. Regardless of how you set the sliders, Photoshop applies your changes evenly to all channels in the image; the selected channel is merely used for the calculation. You can select any channel regardless of the settings of the Channels check boxes. For example, if you select Red from the pop-up menu, Photoshop applies the Blend If values according to the contents of the red channel even if you deselect the Red check box. In other words, the contents of the red channel are used to calculate how the green and blue channels in the layer merge with the rest of the image. ✦ This Layer: This slider bar lets you exclude ranges of colors according to brightness values in the active layer. When you exclude colors by dragging the black triangle to the right or the white triangle to the left, the colors disappear from view. ✦ Underlying Layer: This slider forces colors from the underlying layers to poke through the active layer. Any colors not included in the range set by the black and white triangles cannot be covered and are therefore visible regard- less of the colors in the active layer. ✦ Preview: Select the Preview check box to continually update the image win- dow every time you adjust a setting. The slider bars are far too complicated to fully explain in a bulleted list. To find out more about these options, read the following sections. Note 6 Photoshop 6 634 Part IV ✦ Layers, Objects, and Text Color exclusion sliders The first slider bar, This Layer, hides pixels in the active layer according to their brightness values. You can abandon dark pixels by dragging the left slider triangle, and abandon light pixels by dragging the right slider triangle. Figure 13-19 shows examples of each. ✦ To create the first example, I first set the blend mode to Screen. Then I dragged the left slider bar until the value immediately to the right of the This Layer label read 170, thereby hiding all pixels whose brightness values were 170 or lower. ✦ To create the second example, I changed the blend mode to Multiply. I reset the left slider triangle to 0 and dragged the right slider triangle to 120, which hid those pixels with brightness values of 120 or higher. Figure 13-19: Two examples of modifying the blend mode and This Layer settings inside the Layer Style dialog box. Screen, This Layer: 170, 255 Multiply, This Layer: 0, 120 635 Chapter 13 ✦ The Wonders of Blend Modes Drag the triangles along the Underlying Layer slider bar to force pixels in the under- lying layers to show through, again according to their brightness values. To force dark pixels in the underlying image to show through, drag the left slider triangle; to force light pixels to show through, drag the right slider triangle. Here’s how I achieved the effects in Figure 13-20: ✦ To achieve the effect in the top example in Figure 13-20, I started off by applying the Hard Light mode. (Those blend modes, they’re keepers.) Then I dragged the left slider triangle until the first Underlying Layer value read 140. This forced the pixels in the sunset that had brightness values of 140 or lower to show through. ✦ In the second example, I changed the blend mode to Overlay. Then I dragged the right Underlying Layer slider triangle to 150, uncovering pixels at the bright end of the spectrum. Figure 13-20: Here I changed the Underlying Layer slider bar settings to force through the darkest (top) and lightest (bottom) pixels in the sunset. Hard Light, Underlying Layer: 140, 255 Overlay, Underlying Layer: 0, 150 636 Part IV ✦ Layers, Objects, and Text Bear in mind, every single adjustment made inside the Layer Style dialog box is temporary. The slider bars hide pixels; they don’t delete them. As long as the layer remains intact, you can revisit the Layer Style dialog box and restore hidden pixels or hide new ones. Fuzziness The problem with hiding and forcing colors with the slider bars is that you achieve some pretty harsh color transitions. Both Figures 13-19 and 13-20 bear witness to this fact. Talk about your jagged edges! Luckily, you can soften the color transitions by abandoning and forcing pixels gradually over a fuzziness range, which works much like the Fuzziness value in the Color range dialog box, leaving some pixels opaque and tapering others off into transparency. To taper the opacity of pixels in either the active layer or the underlying image, Alt- drag one of the triangles in the appropriate slider bar. The triangle splits into two halves, and the corresponding value above the slider bar splits into two values sep- arated by a slash, as demonstrated in Figure 13-21. Figure 13-21: Alt-drag a slider triangle to split it in half. You can then specify a range across which brightness values fade into transparency. The left triangle half represents the beginning of the fuzziness range — that is, the brightness values at which the pixels begin to fade into or away from view. The right half represents the end of the range — that is, the point at which the pixels are fully visible or invisible. Figure 13-22 shows some fuzziness applied to the This Layer slider. Here are the specifics: ✦ In the top example, I set the blend mode to Multiply. I left the first This Layer triangle set to 0. I Alt-dragged the second triangle to split it. And I moved the left half of the split triangle to 55 and the right half to 128. The result is a grad- ual drop off. All pixels with brightness values of 0 to 55 are opaque, the pixels become gradually more translucent from 56 to 127, and pixels brighter than 128 are transparent. Alt-drag 637 Chapter 13 ✦ The Wonders of Blend Modes ✦ Next, I duplicated my layer and switched the blend mode to Screen. After splitting the first slider triangle with an Alt-drag, I set one half of the triangle to 128 and the other to 220. I dragged both halves of the second This Layer triangle back to 255. The darkest pixels are transparent, they fade into view from 129 to 219, and they become opaque from 220 on up. As shown in the bottom example in Figure 13-22, the result is a perfect blending of Multiply and Screen, with the sunset showing through in the gray areas. Figure 13-22: By Alt-dragging a This Layer slider triangle, you can create gradual transitions between the opaque and transparent portions of a layer. Multiply, This Layer: 0, 55/128 Duplicate layer, Screen, This Layer: 128/220, 255 638 Part IV ✦ Layers, Objects, and Text Using the Underlying Layer slider is a bit trickier. It typically works best when you’re trying to force through very bright or dark details, such as the highlights in the sun- set sky and the shadows in the water. It also helps to work with a foreground layer that has lots of flat areas of color for the background to show through. Here’s what I did to create Figure 13-23: ✦ For starters, I applied Filter ➪ Other ➪ High Pass to my thinker layer, as in the first example of Figure 13-23. This created lots of gray areas for the underlying pixels to shine through. ✦ I applied the radical Color Dodge mode to this layer. I left the first Underlying Layer triangle at 0. Then I split the second one and moved the left half to 80 and the right half to 200. This forced through the darkest pixels, fading them out as they got lighter. ✦ Next, I duplicated the layer, applied the Color Burn mode, and fiddled with the Underlying Layer triangles until the values read 100/150 and 180/255. The result is a vibrant composition that nicely sets off the thinker’s tattoos. Using Channel Operation Commands Image ➪ Apply Image and Image ➪ Calculations provide access to Photoshop’s chan- nel operations, which composite one or more channels with others according to predefined mathematical calculations. Although once hailed as Photoshop’s most powerful capabilities, channel operations have been eclipsed by the standard and more accessible functions available from the Layers and Channels palettes. One day, I suspect Adobe will scrap Apply Image and Calculations altogether. But until that day, I will dutifully document them both. The Apply Image and Calculations commands allow you to merge one or two identi- cally sized images using 12 of the 17 blend modes discussed earlier plus 2 addi- tional modes, Add and Subtract. In a nutshell, the commands duplicate the process of dragging and dropping one image onto another (or cloning an image onto a new layer) and then using the blend mode and the Opacity settings in the Layers palette to mix the two images together. Although Apply Image and Calculations are more similar than different, each com- mand fulfills a specific — if not entirely unique — function: ✦ Apply Image: This command takes an open image and merges it with the fore- ground image (or takes the foreground image and composites it onto itself). You can apply the command to either the full-color image or one or more of the individual channels. ✦ Calculations: The Calculations command works on individual channels only. It takes a channel from one image, mixes it with a channel from another (or the same) image, and puts the result inside an open image or in a new image window. 639 Chapter 13 ✦ The Wonders of Blend Modes Figure 13-23: After combining a High Pass effect with the radical Color Dodge and Color Burn blend modes, I used the Underlying Layer slider bar to force through pixels from the background so that the sunset and ocean didn’t get lost. High Pass filter Color Dodge, Underlying Layer: 0, 80/200 Duplicate layer, Color Burn, Underlying Layer: 100/150, 180/255 640 Part IV ✦ Layers, Objects, and Text The primary advantage of these commands over other, more straightforward com- positing methods is that they allow you to access and composite the contents of individual color channels without a lot of selecting, copying and pasting, cloning, floating, and layering. You also get two extra blend modes, Add and Subtract, which may prove useful on a rainy day. The Apply Image and Calculations commands provide previewing options, so you can see how an effect will look in the image window. But thanks to the sheer quantity of unfriendly options offered by the two commands, I suggest that you use them on only an occasional basis. The Calculations command can be a handy way to combine masks and layer transparencies to create precise selection outlines. Apply Image is good for compositing images in different color models, such as RGB and Lab (as I explain in the “Mixing images in different color modes” section later in this chapter). But if your time is limited and you want to concentrate your efforts on learning Photoshop’s most essential features, feel free to skip Apply Image and Calculations. I assure you, you won’t be missing much. The Apply Image command Channel operations work by taking one or more channels from an image, called the source, and duplicating them to another image, called the target. When you use the Apply Image command, the foreground image is always the target, and you can select only one source image. Photoshop then takes the source and target, mixes them together, and puts the result in the target image. Therefore, the target image is the only image that the command actually changes. The source image remains unaffected. When you choose Image ➪ Apply Image, Photoshop displays the dialog box shown in Figure 13-24. Notice that you can select from a pop-up menu of images to specify the Source, but the Target item — listed just above the Blending box — is fixed. This is the active layer in the foreground image. If this sounds a little dense, think of it this way: The source image is the floating selection and the target is the underlying original. Meanwhile, the Blending options are the blend modes pop-up menu and the Opacity value in the Layers palette. Using the Apply Image command is a five-step process. You can always simply choose the command and hope for the best, but you’ll get the most use out of it if you do the following. [...]... toward the end of this chapter (For an exception, see the upcoming tip.) ✦ Invert: Select this check box to invert the contents of the source image before compositing it with the target image This option permits you to experiment with different effects The lower-left example in Color Plate 13 -6, for example, shows one use for the Invert check box I inverted the b channel before compositing it with the... quality and detail of the image, 64 5 64 6 Part IV ✦ Layers, Objects, and Text I changed the Scale value to 1.2 to slightly downplay the brightness values and entered an Offset value of 60 to darken the colors uniformly The result of this operation is the more satisfactory image shown in the second example of the figure Add, Scale: 1, Offset: 0 Add, Scale: 1.2, Offset: -60 Figure 13-25: Two applications... channel with all three RGB channels And in the bottom-left image, I chose b from the Channel pop-up menu and 64 3 64 4 Part IV ✦ Layers, Objects, and Text selected the Invert check box, which inverted the b channel before applying it For the final, moderately psychedelic effect in Color Plate 13 -6, I used the Lab image as the destination I switched to the Lab image, chose the Apply Image command, selected... support lines screaming for changes Or the developers were running so behind their deadlines that they were forced to bag the exciting features and devote what little time remained to tweaking the existing stuff For as every software developer knows, if you’re looking for bold new initiatives, don’t look to the users We who use these programs day in and day out have an amazing knack for suggesting the obvious... not forsake pixels and start drawing entirely with shape layers instead? While a shape can clip a continuous-tone photograph, it can’t replace one Although there have been all kinds of experiments using objects and fractals, Chapter 14 ✦ Shapes and Styles pixels are still the most viable medium for representing digital photographs Because Photoshop s primary job is photo editing, pixels are (for the foreseeable... compatibility Photoshop 6 has stretched the TIFF and PDF formats to accommodate any kind of layer — shape layers included — but that doesn’t mean other programs have any idea what Photoshop is doing As I write this, the most recent version of Adobe’s own pagelayout program, InDesign 1.5, doesn’t recognize objects inside TIFF files But it does support PDF files with objects Of all the formats, PDF is... Click the second button if you want to add a path to the Paths palette, great for drawing circular or geometric clipping paths that are a pain in the neck to create with the pen tool Finally, click the third button to draw a pixel-based shape Photoshop doesn’t add a new layer; it merely recolors the pixels on the active layer 65 9 66 0 Part IV ✦ Layers, Objects, and Text New shape layer New work path Filled... Channel pop-up menus may offer Selection, Transparency, and Layer Mask as options But here they have more purpose You can composite layer masks to form selection outlines, selection outlines to form masks, and all sorts of other pragmatic combinations 64 9 65 0 Part IV ✦ Layers, Objects, and Text Figure 13-28 shows how the Calculations command sees selected areas Whether you’re working with masks, selection... target image before choosing the command For example, if the target image is an RGB image shown in the full-color composite view, and you choose RGB from the Channel pop-up menu in the Apply Image dialog box, Photoshop mixes the red, green, and blue channels in the source image with the corresponding red, green, and blue channels in the target image However, if you switched to the red channel before choosing... Don’t believe me? For the past few years, the most commonly voiced request from Photoshop users has had nothing to do with layers, color matching, masking, dynamic effects, history, text warping, memory management, or any of the other hundred or so major capabilities that set Photoshop apart from its competitors Instead, the number one request is — hold onto those hats — CMYK support for the old Gallery . percent throughout. With this setup, each layer blends normally with the one below. 6 Photoshop 6 6 Photoshop 6 632 Part IV ✦ Layers, Objects, and Text Figure 13-18: Here you see how the original. spotlighted area in Figure 13- 16) . If you selected different blend modes for the individual layers in the clipping group, Photoshop uses the mode applied to the base layer for all layers. To adjust. a bulleted list. To find out more about these options, read the following sections. Note 6 Photoshop 6 634 Part IV ✦ Layers, Objects, and Text Color exclusion sliders The first slider bar, This