Lighting Effects - The Photoshop: Professional Retouching and Compositing Tips, Tricks, and Techniques - page 180

Figure 3.18 The gradient light effect has been used to mimic the look and feel of the
fire torch light coming in from the right and cooling down as it spreads.
8. You can also move the light farther in or out of the picture by dragging your cursor
directly over the top of the picture with the Gradient Fill dialog still open. Once the
light is where you prefer, click OK.
Tip
Because this effect is on its own layer, you can use the Opacity slider to control
how strong or weak the effect is. Should you wish to modify the position or color
of the lighting effect, simply double-click the gradient thumbnail in the Layers
panel and open the dialogs as before.
Gradient Lighting: Part 2
A great thing about Photoshop is that there's always more than one way to apply the same
technique.