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Adding Clouds and Spotlights

The five filters in the Render submenu produce lighting effects. You can use Clouds and Difference Clouds to create a layer of haze over an image. Lens Flare creates light flashes and reflections (as mentioned earlier). Lighting Effects lights an image as if it were hanging on a gallery wall. The new kid on the block is the Fibers filter, and like many new kids, it stands a good chance of getting made fun of, beaten up, and mostly ignored.

Creating clouds

The Clouds filter creates an abstract and random haze between the foreground and background colors. Difference Clouds works exactly like layering the image, applying the Clouds filter, and selecting the Difference blend mode in the Layers palette.

Why on earth should Difference Clouds make special provisions for a single blend mode? Because you can create cumulative effects. Try this: Select a sky blue as the foreground color and then choose Filter Render Clouds. Ah, just like a real sky, huh? Now choose Filter Render Difference Clouds. It's like some kind of weird Halloween motif, all blacks and oranges. Press Ctrl+F (Win) or z -F (Mac) to repeat the filter. Back to the blue sky. Keep pressing Ctrl+F (z -F on the Mac) over and over and notice the results. A pink cancer starts invading the blue sky; a green cancer invades the orange one. Multiple applications of the Difference Clouds filter generate organic oil-on-water effects. Figure 11-46 shows an example of Clouds and Difference Clouds.

Figure 11-46: Clouds (left) and Difference Clouds (right) each applied ten times in succession. Repeated applications of the Clouds filter always yield variations on the same theme; repeated applications of Difference Clouds soon result in roiling, plasma-like textures.

Also, if you want to make a repeating texture using Clouds and Difference Clouds, make sure your image size is a square with pixel dimensions based on a power of two — something like 128 by 128 or 256 by 256 will work well. Your cloudy image will seamlessly tile, making it perfect for creating Web page backgrounds and the like.

Using the Fibers filter

Choose Filter Render Fibers to bring up the Fibers dialog box, shown in Figure 11-47. In the preview box, you can view the fibers generated by the filter based on the values of your foreground and background colors. Increase the Variance slider value to create shorter strands of fiber with more contrast between the colors. Ramp up the Strength slider value to make your fibers stringier. The Randomize button calls up a new random seed for the noise; it's a good way to mix it up a bit if the need arises.

Figure 11-47: Photoshop CS debuts the Fibers filter. The world stands in awe.

Lighting an image

The complex Lighting Effects filter enables you to shine lights on an image, color, position, and focus the lights, specify the reflectivity of the surface, and even create a surface map.

When you choose Filter Render Lighting Effects, Photoshop displays one of its most complex dialog boxes, as shown in Figure 11-48. The dialog box has two halves: one in which you position light with respect to a thumbnail of the selected image and one that contains about a billion intimidating options.

Figure 11-48: The Lighting Effects dialog box lets you light an image as if it were hanging in a gallery, lying on a floor, or perhaps resting too near a hot flame.

No bones about it, this dialog box is a bear. The easiest way to apply the filter is to choose one of the predefined lighting effects from the Style pop-up menu at the top of the right side of the dialog box, see how it looks in the preview area, and — if you like it — press Enter or Return to apply the effect.

If you want to create your own effects, you have to work a little harder. Here are the basic steps involved in creating a custom effect.

STEPS: Lighting an Image

Drag from the light icon at the bottom of the dialog box into the preview area to create a new light source. I call this area the stage because it's as if the image is painted on the floor of a stage and the lights are hanging above it.

Select the kind of light you want from the Light Type pop-up menu. It's just below the Style pop-up menu. You can select from Directional, Omni, and Spotlight:

Directional works like the sun, producing a general, unfocused light that hits a target from an angle.

Omni is a bare light bulb hanging in the middle of the room, shining in all directions from a center point.

Spotlight is a focused beam that is brightest at the source and tapers off gradually.

Specify the color of the light by clicking the top color swatch. You can also muck about with the Intensity slider bar to control the brightness of the light. If Spotlight is selected, the Focus slider becomes available. Drag the slider toward Narrow to create a bright laser of light; drag toward Wide to diffuse the light and spread it over a larger area.

Move the light source by dragging at the focus point (if you've chosen a color for your light, the focus point appears as a colored circle in the preview area). When Directional or Spotlight is selected, the focus point represents the spot at which the light is pointing. When Omni is active, the focus point is the actual bulb. (Don't burn yourself.)

If Directional or Spotlight is active, you can change the angle of the light by dragging the hot spot. The hot spot represents the location in the image that's liable to receive the most light. When you use a Directional light, the hot spot appears as a black square at the end of a line joined to the focus point. The same holds true when you edit a Spotlight; the confusing thing is that there are four black squares altogether. The light source is joined to the focus point by a line; the three handles are not.

With Omni or Spotlight in force, you can edit the elliptical footprint of the light. When Omni is in force, a circle surrounds the focus point. When editing a Spotlight, you see an ellipse. Either way, this shape represents the footprint of the light, which is the approximate area of the image affected by the light. You can change the size of the light by dragging the handles around the footprint. Enlarging the shape is like raising the light source. When the footprint is small, the light is close to the image so it's concentrated and very bright. When the footprint is large, the light is high above the image, so it's more generalized.

Introduce more lights as you see fit.

Change the Properties and Texture Channel options as you see fit. I explain these in detail after the steps.

If you want to save your settings for future use, click the Save button. Photoshop invites you to name the setup, which then appears as an option in the Style pop-up menu. If you want to get rid of one of the presets, select it from the pop-up menu and click the Delete button.

Press Enter or Return to apply your settings to the image.

That's almost everything. The only parts I left out are the Properties and Texture Channel options. The Properties slider bars control how light reflects off the surface of your image:

Gloss: Is the surface dull or shiny? Drag the slider toward Matte to make the surface flat and nonreflective, like dull enamel paint. Drag the slider toward Shiny to make it glossy, as if you had slapped on a coat of lacquer.

Material: This option determines the color of the light that reflects off the image. According to the logic employed by this option, Plastic reflects the color of the light; Metallic reflects the color of the object itself. If only I had a bright, shiny plastic thing and a bright, shiny metal thing, I could check to see whether this logic holds true in real life (like maybe that matters).

Exposure: I'd like this option better if you could vary it between Sun Block 65 and Melanoma. Unfortunately, the more prosaic titles are Under and Over — exposed, that is. This option controls the brightness of all lights like a big dimmer switch. You can control a single selected light using the Intensity slider, but the Exposure slider offers the added control of changing all lights in the stage (preview) area and the ambient light (described next) together.

Ambience: The last slider enables you to add ambient light, which is a general, diffused light that hits all surfaces evenly. First select the color of the light by clicking the color swatch to the right. Then drag the slider to cast a subtle hue over the stage. Drag toward Positive to tint the image with the color in the swatch; drag toward Negative to tint the stage with the swatch's opposite. Keep the slider set to 0 — dead in the center — to cast no hue.

The Texture Channel options let you treat one channel in the image as a texture map, which is a grayscale surface in which white indicates peaks and black indicates valleys. (As long as the White is High check box is selected, that is. If you deselect that option, everything flips, and black becomes the peak.) It's as if one channel has a surface to it. By selecting a channel from the pop-up menu, you create an emboss effect, much like that created with the Emboss filter except much better because you can light the surface from many angles at once and it's in color to boot.

Choose a channel to serve as the embossed surface from the pop-up menu. Then change the Height slider to indicate more or less Flat terrain or huge Mountainous cliffs of surface texture.

Figure 11-49 shows an image lit with a total of five spotlights, two from above and three from below. In the first example, I left the Texture Channel option set to None. In the second example, I selected the green channel as the surface map. And in the third example, I filled a separate mask channel with a bunch of white and black dollops using Filter Pixelate Pointillize, and then I selected the mask from the Texture Channel pop-up menu in the Lighting Effects dialog box. The result is a wonderfully rough paper texture.

Figure 11-49: Not only can Lighting Effects enhance your images with simulated directional light, it can also be used to create textures.