Biomedical Engineering Reference
In-Depth Information
A
B
C
Figure 1-5.
A.
A diverging pencil of light rays emerges from a point source.
B.
A
converging pencil of light rays is focused at a point.
C.
An object located at infinity
produces a parallel pencil of light rays. Note that the light rays are perpendicular to
the wavefronts.
Figure 1-6.
An extended object, such as an arrow, may be considered to consist of an
infinite number of point sources. Each point emits diverging light rays.
