Images Formed by Spherical Mirrors

Concave Mirrors

Consider in the rays that diverge from the object and make a small angle with the principal axis. Such rays are called paraxial rays.

Images Formed by Spherical Mirrors

Concave Mirrors

Rays that are far from the principal axis converge to other points on the principal axis, producing a blurred image. The name for this effect is spherical aberration.

Images Formed by Spherical Mirrors

Concave Mirrors

(2.3)

The mirror equation

(2.2)

(2.4)

Images Formed by Spherical Mirrors

Convex Mirrors

Figure shows the formation of an image by a convex mirror—that is, one silvered so that light is reflected from the outer, convex surface. This is sometimes called a diverging mirror because the rays from any point on an object diverge after reflection as though they were coming from some point behind the mirror.

Images Formed by Spherical Mirrors

Convex Mirrors

Images Formed by Spherical Mirrors

Ray Diagrams for Mirrors

Table 2.1

Images Formed by Spherical Mirrors

For concave mirrors, we draw the following three principal rays:

•Ray 1 is drawn from the top of the object parallel to the principal axis and is reflected through the focal point F.

•Ray 2 is drawn from the top of the object through the focal point and is reflected parallel to the principal axis.

•Ray 3 is drawn from the top of the object through the center of curvature C and is reflected back on itself.

Images Formed by Spherical Mirrors

Images Formed by Spherical Mirrors

For convex mirrors, we draw the following three principal rays:

•Ray 1 is drawn from the top of the object parallel to the principal axis and is reflected away from the focal point F.

•Ray 2 is drawn from the top of the object toward the focal point on the back side of the mirror and is reflected parallel to the principal axis.

•Ray 3 is drawn from the top of the object toward the center of curvature C on the back side of the mirror and is reflected back on

itself.