A proximity shadow is another type of cast shadow; it is the shadow you see between two objects that are touching or almost touching. When you press your hands together, for example, they are visually separated by a proximity shadow. When you hold your hands very slightly apart you still see a proximity shadow. It is important in illusionist drawing to indicate proximity shadows, because without them the viewer will have no sense of the separation that exists between one object and another, or between an object and the surface on which it rests. Imagine two limpets on a rock, one in light and one in cast shadow. In spite of the difference in lighting conditions, each will have a proximity shadow. No matter how tightly they hold the rock, they are still separate from it. Look for a proximity shadow whenever two objects make contact or near contact. Here are some important points to remember:
- Proximity shadows exist even within cast shadows.
- Proximity shadows are not greatly altered by the direction or quality of the light.
- In extremely diffused light, proximity shadows are the only cast shadows.
A proximity shadow is what we see as the demarcation between two objects that touch or almost touch.
The tree trunk at left grows out of the ground and appears continuous with it. The trunk at right, however, appears to sit on top of the ground, a physical separation effectively indicated by a proximity shadow.
Proximity shadows are not greatly altered by the strength or direction of the light source. Both limpets have proximity shadows in this illustration.
In very diffused light, proximity shadows will be the primary shadows we see.