Examining Different Types of Shadows

Photoshop Layer Effects includes Drop Shadow. As the name implies, this type of shadow is created when a light source is almost directly above a floating object—the silhouette of the object making the shadow is dropped onto the surface that receives the shadow. Drop shadows are cool for Web graphics and the text on most issues of PC Magazine. In the realm of photorealism, however, objects almost never float above a surface, and lighting is almost never so perfectly directed at an object that the object’s silhouette is the shape of the shadow.

In figure 1, you can see two examples of shadows: the drop shadow and the cast shadow— sometimes called a perspective shadow.

Figure 1

Shadows from floating objects are often drop shadows; shadows that add a casting plane to the image are called cast shadows.

As you can see in this figure, the cartoon fellow with the cast shadow seems anchored to the ground—drop shadows tend to add height to the object, whereas cast shadows add depth to a scene. In the sections to follow, you’ll learn how to add a photorealistic shadow to several images, and in the process, you’ll learn a trick or two about adding accurate shading to modeled scenes or to digitized photographs.