Shapes—circles, squares, triangles, etc.—are easy to identify, and when used as compositional elements they can create simple but very pleasing images. We can find shapes in nature as well as man-made objects. In Figure 4.10, the famous Vatican museum stairwell demonstrates a classic seashell spiral otherwise known as a logarithmic spiral (Figure 4.11). Many architectural structures borrow their shape from naturally occurring forms.
Figure 4.10 The spiral staircase shares the same form as a spiral seashell.
ISO 400 • 1/4 sec. • f/11 • 15mm lens
Figure 4.11 The logarithmic spiral is a great example of a leading line that defines a shape.