Concave Lenses Concave lenses are thinner at the

Concave Lenses

• Concave lenses are thinner at the middle. Rays of light that pass through the lensare spread out (they diverge). A convex lens is a diverging lens. When parallel rays of light pass through a concave lens the refracted rays diverge so that they appear to come from one point called the principal focus.

Concave Lenses • • F 2 F • Rays traveling parallel to the principal axis of a concave lens will refract as if coming from the focus. Rays traveling toward the focus will refract parallel to the principal axis. • 2 F • F 2 F • Rays traveling directly through the center of a concave lens will leave the lens traveling in the exact same direction, just as with a convex lens.

Concave Lens Diagram object • 2 F • F image • F Experiment with this diagram • 2 F No matter where the object is placed, the image will be on the same side as the object. The image is virtual, upright, and smaller than the object with a concave lens.

• Curving inward, concave lenses cause light to spread out, resulting in a smaller image for the viewer. Despite being less useful than convex lenses, concave lenses have several uses, including in eyeglasses and contacts, flashlights, peepholes, binoculars, telescopes, and in photography.