Special Effects - The Photoshop: Professional Retouching and Compositing Tips, Tricks, and Techniques - page 213

Figure 4.6
Tip
Releasing and pressing down with the brush increases the opacity of the light lay-
er showing through the black layer mask.
9. Let's take this a step further and make it appear as though there's a light inside the
doorway that is spilling out onto the road surface. With the same white brush,
change the hardness to 90% and, with the layer mask selected in the Layers panel,
paint inside the doorway and onto the road ( Figure 4.7 ) .