Section 10.7. Using Lighting Effects

10.7. Using Lighting Effects

In this section, I'm talking about lighting effects, such as spotlights and lens flares projected onto a background or inside a selection. I'm not talking about redirecting the lighting falling on a subject to match it to the background in a montage, that process is covered in Chapter 9 in the "Lighting and Casting Shadows" section.

I use lighting effects a lot for lighting the backgrounds of portraits and product shots that were originally shot on green screens. I have also used them in the form of lens flare filters and for simulating lens flare caused by shooting directly into a lighting source such as the sun or a spotlight.

Speaking strictly from a nondestructive point of view, you should make a separate layer for your lens flares. However, I often mix them on the same layer as my lighting effects, just to save hard drive space.

10.7.1. Using the Lighting Effects and Lens Flare Filters

The Lighting Effects filter casts light onto an image originating from three types of light sources: Omni, Directional, and Spotlight. Directional places a wide beam across the image. Omni is a circle of light radiating equidistantly from the center handle. Spotlight is adjustable and can produce virtually any kind of a beam. The Lighting Effects filter lets you add these to an image in any arrangement, and at any size. You can brighten and dim the individual lights, as well as the overall room light. You can also imitate placing colored filters over the lights. One of the coolest things is that you can use the Lighting Effects filter to texture the entire layer you're lighting. The direction of the shadows on the texture will depend on the light that is affecting that part of the texture. Figure 10-17 shows a portrait before and after application of the Lighting Effects filter.

Figure 10-17. A portrait before and after application of the Lighting Effects filter.

Once again, this technique is highly destructive to the layer to which you apply it once you click the OK button. So be sure to keep a hidden duplicate layer somewhere in the image in case you have to make a change, which will prevent you from doing everything over to create that layer, even if all it amounted to was spending the time it took to find and qualify the right image.

The Lens Flare filter simulates what would happen if you pointed several different types of lenses at a very bright light source that was aimed directly at the camera. I often use it to simulate exactly that when I want to dramatize a sunset photo or a rock performance with spotlights in the background. Often, when you actually include bright lights in the shot, some important portion of the image is flared out. With the Lens Flare filter, you can position the flare(s) exactly where they most benefit the subject and the composition.

To save a bit of space in this book, I combined both techniques on the image in Figure 10-17. Lighting effects are almost always (but not necessarily) on a pasted-in background behind a knocked-out subject. You can see the subject and the background before the lighting effects on the left side of Figure 10-17. Here's how the whole thing is done.

1. Duplicate the layer that is the background image for the knockout, just in case you irretrievably mess it up with lighting effects and need to start over.

2. Start with lighting effects if you're going to apply both Lighting Effects and Lens Flare. I find it usually makes it easier to decide where to put the lens flare. Choose FilterRenderLighting Effects. The Lighting Effects dialog appears, as shown in Figure 10-18.

   Figure 10-18. The Lighting Effects dialog remembers what you did the last time you used it so you can go back and make changes if you don't like what you see when you click OK. Also, if you check the Preview box, you'll see the results of your adjustments on the image itself.

   The Lighting Effects filter may look frighteningly complex if you're new to it. Knowing a few things will likely make it much easier. First, you can have as many light sources as you want. To introduce a new light source, drag the Light Bulb icon into the image in the Preview window. You can relocate it with the cursor any time you want. If you decide you want to get rid of a light source, just drag it to the Trash icon.

   NOTE

   If you want to take the easy way out, the Style menu contains seventeen premade lighting configurations. You can often save yourself a lot of time, especially if you are new to this, by browsing through the premade style until you find the one closest to the effect you're looking for. You can still change all the variables for any of the lights. And if you find an effect that you especially like, you can save it so that it can be recalled any time. Click the Save and Delete buttons.

3. Choose the size and shape of your light sources. To make the light source into an Omni, drag the side handles until the light's marquee is a circle. To make it a Directional light, increase the diameter of the circle and then drag the end of the marquee until the oval is several times longer than it is wide. When you drag in a new light source, it's always the same type as the last one you used. To change it to another type, choose another type from the dialog's Light Source menu.

4. Adjust the Intensity and Ambiance sliders firstthey are the most important. Intensity refers to the relative brightness of the currently chosen light source. Ambiance controls the overall brightness of the background.

5. Experiment with the Exposure slider. Exposure lightens or darkens both the lights and the overall image simultaneously. It's very helpful to let you match the brightness of your background to the brightness of your image.

6. Experiment with the Gloss and Material sliders to get the background shininess that you like.

7. Match the noise in the background with the noise in the image.

NOTE

You can also choose any of the image's channels as a texture channel. However, you have to place a monochrome image into an Alpha channel first. You can create a bump map from any photographic pattern, such as a close-up of a piece of fabric or of a tiled floor or by simply painting a texture into a blank file. Whatever is white in the bump map appears to be higher, while darker tones appear to be lower. Figure 10-19 shows a monochrome bump map on the left and how its result looks in the Lighting effects filter on the right.

Figure 10-19. Left, a bump map made from nighttime neon; right, the bump map applied in the Lighting effects filter.

NOTE

In "real life", lens flare is caused when a very bright light source is aimed directly at the lens. Unless that light source is very narrow and highly focused, it will cause a backlight rim around the foreground object (such as people). So if you really want the lens flare effect to be realistic, try selecting and then feathering the foreground objects. Use that selection as a mask for an Adjustment layer and use the adjustment (Levels, Curves, Brightness/Contrast) to brighten the background so that a rim of light appears around the foreground objects.

10.7.2. Making Your Own Lighting Effects

You can create your own lighting effects with a mask that lets the light through in varying degrees of opacity, then using it to mask an adjustment layer. In Figure 10-20, the adjustment layer mask is on the left and the lit subject is on the right.

Figure 10-20. The lighting mask (left) and the result on the subject (right).

I did this by creating a blank layer above the layer I want to light, then used the Lasso tool to select the area to light the brightest and filled that area with pure, 100 percent Opacity White. Next, I used the Brush tool to paint areas of progressively lighter gray around the white areas. To smooth everything out and blend the shades of gray, I blurred that layer with a Gaussian Blur filter. I turned off all the other layers and copied the image to the clipboard, then opened the Channels palette and clicked the New Channel icon to create a new Alpha Channel. I selected that channel, pasted in the Clipboard contents, clicked the RGB channel to go back to the Layers palette, and dragged the lighting layer to the trash. Next I opened the Curves adjustment layer. The Brightness/Contrast adjustment layer is OK when you're in a hurry, but Curves will give you a lot more control.