Three Dimensional Field: Depth and Volume

When you think about creating depth and volume, remember:

What the camera sees is crucial

(or, if you're developing multimedia using another type of tool, what is captured and placed into the frame...)

The Z-Axis

The Z-axis is the depth axis and extends from the screen back indefinitely.
Ducky Example

Graphic Depth Factors

The following aspects of visual perception create the dimension of depth:

Overlapping Planes.

Overlapping planes: Elements in front are considered closer

Relative size: Larger elements are perceived as closer; the smaller an object appears relative to the screen space, the farther we perceive ourselves to be. Close-ups make objects and people seem close because of the relative screen space they take up
Height in the plane: Elements higher on a plane seem farther away when other cues aren't present Fistful example

Linear perspective.

Linear perspective: Parallel lines and elements that follow lines, appear to recede, or become smaller in the distance. Parallel element are perceived to converge at the "vanishing point" on the horizon line. The horizon line indicates eye level.

Forced perspective: Use elements of an image to take advantage of linear perspective by creating the appearance of depth. For example, you can adjust camera angle during filming to make a road or path seem longer. Graphic images can be adjusted similarly.
Aerial Perspective: Elements that appear faded, misty, or obscured tend to recede visually. Elements that are sharp, bright, or have a higher color or light value than their surroundings, tend to advance.
Thin Red Line Example

Camera Angles for Depth

If you are using a still camera or a digital camera, use the following guidelines.

Wide angle lens (greater depth of field)

Reduces the impact of overlapping planes
Exaggerates relative size so that elements seem farther apart (stretched along the z-axis)
Accelerates convergence of parallel lines, increases the distance of the vanishing point
De-emphasizes aerial perspective

Narrow angle lens (reduced depth of field)

Enhances the depth cuing of overlapping planes.
Diminishes differences in relative size so elements seem closer together (squeezed along the z-axis)
Retards convergence, decreases the distance of the vanishing point
Emphasizes aerial perspective

Aerial Perspective

Selective focus: Feature an object in the foreground, middle-ground or background by making it appear in focus and the objects in the other positions out of focus (fuzzy)
Rack-focus: Shift the emphasis in a shot by changing the focus (racking through) rather than by changing the camera or object position. Racking through requires a narrow angle lens and lower illumination.