Photoshop.CS.Bible [Electronic resources] نسخه متنی

Chapter 5's brush modes both in name and in function, we're covering some familiar territory. But you'll soon find that there's a big difference between laying down a color or pattern with a brush and merging the myriad colors that inhabit a single layer. This difference is the stuff of the following pages.

For you visual learners, I'll be demonstrating the effects of Normal, Luminosity, and the others using the images pictured in Figure 13-7. The default order of the images is that shown in the figure — that is, the Blistered Paint pattern (one of the predefined patterns included with Photoshop CS) on top and the tranquil background at the bottom. However, I sometimes slide the pattern layer below the gradient layer if it better suits the discussion. In any case, bear in mind how these control images look because I'll be using two or more of them in future figures.

Figure 13-7: To demonstrate the effects of Photoshop's blend modes, I'll be compositing these images in more or less the order shown here (with some occasional swapping around). The tranquil background is in fact the background layer, so no blend mode will ever be applied to it. Note that the right half of the face layer is transparent, and the layer includes an automated drop shadow, fading off to the right.

Some of the shortcut letters make perfect sense — Shift+Alt+N for Normal and Shift-Option-S for Screen. Others are a bit of a stretch — such as Shift+Alt+W for Linear Dodge or Shift-Option-Z for Pin Light. That's why I've come up with the following helpful pneumonic. Reading from the top of the blend mode menu to the bottom, it's "Nik mba gsd wof hvjzl ex utcy," pronounced "Nick mubba gus-sid woff heev-jizzel ex ootsie." Sing that to a song Big Bird might have sung (see Figure 13-8), and you'll have your blend mode shortcuts memorized in no time.

Figure 13-8: Just sing this magical word and you'll be fine. I promise.

Of course, it's always possible a few people won't be able to wrap their brains around my little ditty. Which is why I list the shortcut letter in parentheses with each blend mode description and illustrate the shortcut inside the figures. So whether predictable or not, we got your blend modes covered.

Cool? Keen. So without any further notes or clarifications, here they are, the 23 blend modes, in order of appearance:

Normal (N): In combination with Opacity and Fill settings of 100 percent, this option displays every pixel in the active layer normally, regardless of the colors in the underlying layers. When you use opacity values (whether Opacity or Fill) of less than 100 percent, the color of each pixel in the active layer is averaged with the composite pixel in the layers behind it. Figure 13-9 shows examples applied to the face layer on its own.

Figure 13-9: The face layer subject to the Normal mode when combined with Opacity values of 100 percent (top) and 60 percent (bottom). The superimposed character indicates the keyboard shortcut Shift+Alt+N (Shift-Option-N on the Mac) and 6 for 60-percent opacity.

Dissolve (I): This option affects feathered or softened edges. If the active layer is entirely opaque with hard edges, Dissolve has no effect. But when the edges of the layer fade into view, as is the case around the neck and chin in Chapter 14, layer effects are governed by their own, independent blend modes. Things change, however, when you drop the Opacity value below 100 percent, in which case Dissolve dithers all pixels, as demonstrated in the second example in the figure.

Figure 13-10: Here I applied the Dissolve mode to a layer at an Opacity setting of 100 percent (top) and 60 percent (bottom). Instead of creating translucent pixels, Dissolve turns pixels on and off to simulate transparency, as shown by the magnified details.

Darken (K): The first of the four darkening modes, Darken applies colors in the active layer only if they are darker than the corresponding pixels below. Keep in mind that Photoshop compares the brightness levels of pixels in a full-color image on a channel-by-channel basis. So although the blue component of a pixel in the active layer may be darker than the blue component of the underlying composite pixel, the red and green components may be lighter. In this case, Photoshop would assign the blue component but not the red or green, thereby subtracting blue and shifting the pixel toward yellow. Darken is most useful for covering up light portions of an image while letting dark areas show through.

To illustrate Darken and the other darkening modes, I first established a light background by setting the pattern layer on top of the background and lowering its Opacity to 70 percent. Then I placed the gradient layer on top of that and set it to the Screen mode, which left the white portion of the gradient visible and dropped out the black portion. The result appears in the top example of Figure 13-11. I then added the face layer and set it to the Darken mode, as shown at the bottom of the figure. The result is a face that appears smooth in both the midtones and the shadows and patterned in the light areas, with relatively sharp transitions between the two.

Figure 13-11: A backdrop composed of the background, pattern, and gradient layers (top) followed by an applica- tion of the face in the Darken mode (bottom). Only those pixels in the face that are darker than the pixels in the patterned backdrop remain visible.

Multiply (M): Multiply is one of the rare blend modes that emulates a real-world scenario. Imagine that the active layer and the underlying composite are both photos on transparent slides. The Multiply mode produces the same effect as holding these slides up to the light, one slide in front of the other. Because the light has to travel through two slides, the outcome invariably combines the darkest elements from both images. So unlike Darken, Multiply universally darkens, resulting in smooth transitions that are ideal for preserving contours and shadows, as in the top image of Figure 13-12.

Figure 13-12: The Multiply blend mode (top) produces the same effect as holding two overlapping transparencies up to the light. To get an even darker effect, I duplicated the layer, removed its drop shadow, and merged the two face layers into one (bottom).

Color Burn (B) and Linear Burn (A): If the Multiply mode darkens your image, the two Burn modes char them. They both use colors in the active layer to reduce brightness values, resulting in radical color transformations. As demonstrated in Figure 13-13, Color Burn results in crisp, often colorful, toasted edges; Linear Burn creates a smoother, less vibrant effect. Both modes have an uncanny capability to draw colors from background layers. For example, even though I lightened the background by applying Screen to the pattern layer in Figure 13-13, we see more contrast in this figure than in the single-pass Multiply example from Figure 13-12. So for high-contrast stamping effects, these are the blend modes to use.

Figure 13-13: After applying Screen to the pattern layer, I applied the Color Burn (top) and Linear Burn (bottom) blend modes to the face layer. Even though the back- ground is lighter, many portions of the face appear darker than they did after a single application of Multiply.

Lighten (G): Inside the Layer Style dialog box" in the next chapter. (If you're having problems finding this discussion, look for the bright and helpful Figure 14-18.)

Figure 13-14: Here I prepared a dark background by assigning Multiply to the gradient layer (top). Then I applied Lighten to the face layer and changed its drop shadow to white (bottom).

Screen (S): From a creative standpoint, Screen is the opposite of Multiply. In fact, remember those transparent slides from the Multiply analogy? Well this time, place them both in separate projectors and point them at the same screen. The result is the effect you get with Screen. Rather than creating a darker image, as you do with Multiply, you create a lighter image, as demonstrated in Figure 13-15.

Figure 13-15: The Screen mode produces the same effect as shining two projectors at the same screen. In this case, one projector contains the background layers, and the other contains the face (top). Want a more pronounced ghosting effect? Just duplicate the Screen layer (bottom).

You can use the Screen blend mode to emulate film that has been exposed multiple times. Ever seen Thomas Eakin's pioneering Jumping Figure, which shows rapid-fire exposures of a naked man jumping from one location to another? Each shot is effectively screened onto the other, lightening the film with each and every exposure. The photographer was smart enough to limit the exposure time so as not to overexpose the film; likewise, you should only apply Screen when working with images that are sufficiently dark so that you avoid overlightening. Screen is equally useful for creating glows, retaining just the light colors in a gradient, and creating light noise effects such as snow and stars.

Color Dodge (D) and Linear Dodge (W): When you apply one of the two Dodge modes, each color in the layer becomes a brightness-value multiplier. Light colors such as white produce the greatest effect, and black drops away. As a result, the Dodge modes are Photoshop's most dramatic whitening agents, the equivalent of mounting your image on a gel and projecting it from a spotlight. (This is not an exact equivalent, mind you, but it's close enough to give you an idea of what to expect.) Of the two, Color Dodge produces the sharper, rougher effect; Linear Dodge smoothes out the transitions (see Figure 13-16). Because they send so much of an image to white, the Dodge modes are most useful for simulating hot spots and other intensely bright effects.

Figure 13-16: After slightly darkening the gradient layer and fading the pattern layer, I applied Color Dodge (top) and Linear Dodge (bottom) to the face. Never subtle, both modes simultaneously bleach the image and draw out some of the dark outlines from the Blistered Paint pattern.

Overlay (O), Soft Light (F), and Hard Light (H): Photoshop's six Light modes darken the darkest colors and lighten the lightest colors, thereby allowing the midtones to intermix, so that foreground and background remain independently identifiable. Of the six, the first three — Overlay, Soft Light, and Hard Light — are the oldest and arguably the most useful, so I'll begin with them.

Each of these three modes alternatively multiplies the blacks and screens the whites, but to different degrees. For example, where Overlay favors the background layers, Hard Light emphasizes the active layer. In fact, the two are direct opposites — Layer A set to Overlay in front of Layer B produces the same effect as Layer B set to Hard Light in front of Layer A. Meanwhile, Soft Light is a modified version of Hard Light that results in a more subtle effect than either Hard Light or Overlay.

When experimenting with these modes, my advice is to always start with Overlay. If Overlay produces too strong an effect, reduce the Opacity or Fill value to favor the composite pixels. Figure 13-17 shows three compositions created using the background, face, and pattern layers. Throughout, the face is set to Normal, fully opaque. To add texture to the image, I set the blend mode for the pattern layer to Overlay. But as we can see in the first example, this overwhelms the image. So I pressed the 5 key to reduce the Opacity to 50 percent, resulting in the second image.

Figure 13-17: With the pattern layer in front, I applied the Overlay mode (top), experimented with reducing its Opacity setting to 50 percent (middle), and finally settled on the Soft Light mode with an Opacity of 100 percent (bottom).

Alternatively, you can switch from Overlay to Soft Light, as I did in the final example of Figure 13-17. On first glance, the second and third examples in the figure — one showing Overlay at 50 percent and the other Soft Light at full opacity — look almost identical. But on closer inspection, you will notice that where the balance of lights and darks is roughly equivalent, their distribution is quite different. The Overlay example favors the details in the face; the Soft Light example favors the marbleized edges of the Blistered Paint pattern.

On the other hand, if the Overlay mode at 100 percent seems too subtle, you can try cloning the layer to double the Overlay effect or switching to the Hard Light mode. Figure 13-18 demonstrates the difference. I start with the gradient layer set to Screen and the face set to Overlay. (For the present, the pattern layer is hidden.) The face is too light, so I clone the face to another layer by pressing Ctrl+J (z -J on the Mac) and delete its drop shadow. The final image compares this effect to sticking with a single layer and applying the Hard Light mode instead. In this particular case, Hard Light provides the best marriage of emphasis on the face and balance with the background.

Figure 13-18: Here I have the face layer in front with the gradient set to Screen behind it. Working on the face, I first applied the Overlay mode (top) and then duplicated the face to another layer (middle). I didn't like the contrast, so I deleted the cloned layer and changed the original to Hard Light (bottom).

Vivid Light (V) and Linear Light (J): If Overlay and its ilk combine Multiply and Screen, the next two Light modes combine Dodge and Burn. More specifically, Vivid Light combines Color Dodge and Color Burn, where Linear Light combines Linear Dodge and Linear Burn. Figure 13-19 shows examples. This time, I've reduced the Opacity setting for the gradient layer to 50 percent and brought back the pattern layer, also at 50-percent Opacity but set to Soft Light. Sandwiched in between is the face, set to Vivid Light at top and Linear Light at bottom.

Figure 13-19: The effect of setting the face to the Vivid Light (top) and Linear Light (bottom) modes. Because the effects are so hot, I sandwiched them between a Soft Light pattern layer and a Screen gradient layer, each with Opacity settings of 50 percent.

I find both modes useful for enhancing contrast, especially when combined with gradients. In Figure 13-20, we have the usual gang: the Blistered Paint pattern at 50-percent Soft Light and the face layer at 100-percent Normal. But this time, I've alternated the gradient layer, fully opaque, between Vivid Light in the first example and Linear Light in the second. In the final example, I cloned the face and set it to Linear Light as well. Both gradient and face set to Linear Light invokes a heightened, haunting effect; cloning the face before applying Linear Light prevents the face and gradient from interacting.

Figure 13-20: The effects of applying Vivid Light (top) and Linear Light (middle) to the gradient layer. In both cases, the Opacity value is 100 percent. I then cloned the face layer and set it to Linear Light as well (bottom).

Pin Light (Z): One of the simplest modes in all of Photoshop, Pin Light keeps the darkest blacks and the lightest whites, and then makes everything else invisible. For the sake of comparison, the first example of Figure 13-21 shows the gradient layer set to Pin Light. (The face has been restored to Normal.) As you can see, only the very top and bottom of the gradient are visible; otherwise, the tranquil background lies exposed.

Figure 13-21: After returning the face to the Normal mode, I set the gradient layer to Pin Light (top). Then I cloned the face and sharpened the edges using the Unsharp Mask filter (middle). Finally, I applied the Pin Light mode to keep just the lightest and darkest pixels (bottom).

I find Pin Light particularly useful for modifying edge filters. In the second example of Figure 13-21, I cloned the face to a new layer and applied Filter Sharpen Unsharp Mask with an Amount of 100 percent and a Radius of 20 pixels. By applying the Pin Light mode, I retained just the lightest and darkest edges of the sharpened layer, as the final image shows. The result is a more subtle effect that still manages to exhibit thick, high-contrast outlines.

PhotoshopHard Mix (L): The first time you apply this new blend mode to an image, you may be inclined to run screaming from your computer and hide under your bed until your screen saver kicks in. Oh, all right, it's not that bad. But the results that Hard Mix produces aren't pretty. Think functional as opposed to beautiful, and you'll be on the right track.

The Hard Mix blend mode combines image layers using the Vivid Light blend mode and then performs a color threshold operation on them. If you like, you can do it manually: Take two layers blended with Vivid Light and press Ctrl+Shift+E (z -Shift-E on the Mac) to merge them. Then switch to the Channels palette and select the red channel to isolate it. Choose Image Adjustments Threshold. When the Threshold dialog box appears, click OK to accept the default settings. Repeat this process with both the green and blue channels, click the RGB channel item to view the composite image, and there you have it — a homemade, do-it-yourself Hard Mix, much like the one in Figure 13-22. I bet right now you're thanking your lucky stars that Adobe has simplified the process by doing it all for you in a single blend mode.

Figure 13-22: In the top image, I've set only the face layer to Hard Mix. Although it is by no means smooth or antialiased, the Hard Mix blend mode has done a great job of completely isolating the eyes from the face. As you can see in the bottom image, applying Hard Mix to a number of layers results in something of a catastrophe.

On the other hand, you may be wondering why on Earth you'd ever want to achieve this effect, and you may also be wondering what exactly you just did to your image. Essentially, Hard Mix pushes the colors in an image's blended pixels to their absolute extreme: A hint of auburn becomes a harsh, deafening red; a sprinkle of cool aquamarine is transformed into bright, brash blue; you get the picture. All in all, Hard Mix leaves you with only eight colors for your pixels: black, white, red, green, blue, cyan, magenta, and yellow. Consider the fact that you're likely downsizing from roughly 16 million colors, and you begin to understand why the effect looks less than appealing.

But believe it or not, a color threshold created with the Hard Mix blend mode has its uses, rare as they may be. For a closer look at some effects you might be able to pull from thresholds, check out Chapter 17.

Difference (E) and Exclusion (X): Difference inverts lower layers according to the brightness values in the active layer. White inverts the composite pixels absolutely, black inverts them not at all, and the other brightness values invert them to some degree in between. In the first example of Figure 13-23, I applied the Difference mode to the face layer, which is set against the gradient layer set to Screen. The light colors from the background show through the black pixels around the eyebrows, nose, and mouth, while the light areas in the face invert the lake and mountains.

Figure 13-23: When you apply the Difference mode (top), white pixels invert the pixels beneath them; black pixels leave the background untouched. The Exclusion mode (bottom) performs a similar effect, but instead of inverting medium colors, it changes them to gray.

Exclusion works just like Difference except for one, er, difference. Illustrated in the second example in Figure 13-23, Exclusion sends midtones to gray — much as Pin Light sends midtones to transparent — creating a lower-contrast, often smoother effect.

Because these modes invert colors, they can produce interesting effects when combined with inverted layers. Figure 13-24 shows examples in which Difference is applied to the face. In the first example, I inverted the face layer by pressing Ctrl+I (z -I on the Mac). In the second example, I restored the face to its previous appearance and then inverted the gradient layer, so it went from white at the top to black at the bottom.

Figure 13-24: Because the Difference mode inverts colors, it only stands to reason that you can invert Difference layers and neighboring layers to achieve still more effects. Here I've alternated between invert- ing the face layer (top) and the gradient (bottom). In both cases, the face is set to Difference and the gradient is set to Screen.

Hue (U): Hue and the remaining three blend modes make use of the HSL color model to mix colors between the active layer and the underlying composite. When you select Hue, Photoshop retains the hue values from the active layer and mixes them with the saturation and luminosity values from the underlying image.

Saturation (T): When you select this option, Photoshop retains the saturation values from the active layer and mixes them with the hue and luminosity values from the underlying image. Saturation produces such subtle effects that you'll typically want to apply it in combination with other blend modes. For example, after applying a random blend mode to a layer, you might duplicate the layer and then apply the Saturation mode to either boost or downplay the colors, much like printing a gloss or matte coating over an image.

Color (C): This option combines hue and saturation. Photoshop retains both the hue and saturation values from the active layer and mixes them with the luminosity values from the underlying layers. Because the saturation ingredient of the Color mode produces such a slight effect, Color frequently produces a very similar effect to Hue.

Luminosity (Y): The Luminosity blend mode retains the lightness values from the active layer and mixes them with the hue and saturation values from the composite pixels below. So just as the Color mode uses the layer to colorize its background, the Luminosity mode uses the background to colorize the layer.

Color Plate 13-1 gives you a sense of the wonders you can achieve by combining a mere trio of blend modes — one each from the Lighten, Light, and HSL categories. The page begins with the two base layers, the face and the tranquil background. The face is fully opaque and set to Normal. In the second image, I introduce three more layers, including the by-now familiar pattern and gradient, as well as an old postage stamp. The gradient and stamp are set to Normal with the stamp lowered to an Opacity value of 70 percent; the pattern enjoys the Overlay blend mode and an Opacity setting of 30 percent. In the final image, I changed the gradient layer to the Screen mode and reduced the Opacity setting to 60 percent. Then I assigned Luminosity to the face and stamp.

Or did I? Clearly if you look at the color plate, you can see that the brightness values from the face and stamp interact with the colors from the background. But had I applied Luminosity independently to the layers, they would interact with each other as well, with some of the blend of background and stamp leaking into the face. And yet, there is no such interaction. It's as if the stamp thinks the face is opaque, while the background can see through both.

Blend mode madness

Remember that scene in Amadeus where Mozart is telling the king about some obscure opera that he's writing — "Marriage of Franz Joseph Haydn" or something like that — and he's bragging about how many folks he has singing on stage at the same time? You do remember that scene, don't you? Oh, you're not even trying. Anyway, you can do that same thing with Photoshop. Not with melody or recitative or anything like that, but with imagery. Just as Mozart might have juggled several different melodies and harmonies at once, you can juggle layers upon layers of images, each filtered differently and mixed differently with the images below it.

Predicting the outcome of these monumental compositions takes a brain the magnitude of Mozart's. But experimenting with different settings takes no intelligence at all, which is where I come in.

The hierarchy of blend modes

The most direct method for juggling multiple images is "sandwiching." By this I mean placing a heavily filtered version of an image between two originals. This technique is based on the principal that more than half the blend modes — including Normal, Dissolve, Color Dodge and Burn, the seven Light modes, and the four HSL modes — change depending on which of two images is on top.

For example, Figure 13-25 shows two layers, A and B, and the result of blending them with the Overlay mode. When the man is on top, as in the third example, the Overlay mode favors the sun. But when the sun is on top, Overlay favors the man. How fair is that?

Figure 13-25: After establishing two layers, sun and man, I placed the man on top and applied Overlay to get the third image. Then I switched the order of the layers and applied Overlay to the sun to get the last image.

Fortunately, Overlay is balanced by its opposite, Hard Light, which operates with a keener sense of justice, favoring the layer to which it's applied. For example, I could have achieved the exact effect shown in the third example of Figure 13-25 by placing the man under the sun and setting the sun to Hard Light. Flip-flop the layers and apply Hard Light to the man to get the last example.

Another obvious example of blend mode opposites is Color and Luminosity. If I were to position the man in front of the sun and apply Color, the sun would turn a kind of peachy, fleshy color. The same thing would happen if I placed the sun in front and applied Luminosity.

The moral of this minutia is that the order in which you stack your layers is as important as the blend mode you select. Even modes that have no stacking opposites — Color Dodge, Linear Light, and others — produce different effects depending on which layer is on top. For your general edification, Figure 13-26 shows a few examples.

Figure 13-26: A series of blend modes shown with the man in front (top row) and the sun in front (bottom row).

Sandwiching a filtered image

When you sandwich a filtered image between two originals — which, as you may recall, is what all this is leading up to — you can lessen the effect of the filter and achieve different effects than those I discussed in Chapter 11. Layers and blend modes give you the flexibility to experiment as much as you want and for as long as you please.

In Figure 13-27, I copied the happy man's face to a new layer and then applied Filter Sketch Charcoal with the foreground and background colors set to their defaults, black and white, respectively. The right-hand image lists the specific settings.

Figure 13-27: The fixings for our blend mode sandwich include the original happy man layer (left) and a cloned version on an independent layer subject to the Charcoal filter (right). The original will be our bread, the Charcoal is our meat. I mean, come on, who wouldn't want charcoaled meat?

Like most filters under the Sketch submenu, Charcoal absolutely destroys the detail in the image, replacing all brightness values with the foreground and background colors, in this case, black and white. Fortunately, because I applied Charcoal to a clone of the image, I can use a blend mode to restore some of the detail. Figure 13-28 shows two of the myriad possibilities that exist — one using the Multiply mode, which kept the blacks in the Charcoal effect and threw away the whites, and the other using Pin Light, which allowed colors from the original image to show through the gray areas of the Charcoal rendering.

Figure 13-28: Each of two blend modes applied to the Charcoal meat in front of a slice of original image bread. This is what we image-editing pro- fessionals like to call an open-face blend mode sandwich, great when you only have time for a light snack.

But that's just the beginning. By once again cloning the background layer and moving it above the Charcoal layer, so that the filtered image resides between two originals, I can increase my opportunity for blend mode variations. In this sandwich, the original images serve as the bread and the Charcoal layer is the meat (or the eggplant, for you vegetarians). Figure 13-29 shows the effects of applying a total of four blend modes to the top slice of bread, which in turn interact with the two blend modes applied to the Charcoal meat in the preceding figure. For example, in the lower-left example, I applied the Multiply mode to the filtered image and the Linear Light mode to the cloned original in front of that. The result is a brightly colored image with charcoal shadows and a bright, white background.

Figure 13-29: When you have a hunger, only a full sandwich will do. Here I've thrown on several top slices of bread, each slathered with a different, delicious blend mode.

Creating a Difference sandwich

Check out the last example in Color Plate 13-2 show a small sampling of the several thousand possible variations on the Difference sandwich theme. In the top rows of both figures, I've vigorously applied a series of standard filters — so vigorously, in fact, that I've pretty well ruined the image. But no fear. By stacking it on top of the original, cloning the original on top of it, and applying the Difference mode to both layers, you can restore much of the original image detail, as shown in the bottom examples of the two figures.

Figure 13-30: Three different filtering effects as they appear on their own (top row), combined with the original image using the Difference mode (middle row), and when inserted into a Difference sandwich (bottom row).