This convex mirror allows drivers and pedestrians to see a wide angle around a blind corner.
Mirrors and lenses are widely used optical devices that can change the way we see images. Curved mirrors and lenses bend the path of light beams to provide magnified, miniaturized, inverted and otherwise distorted versions of the images reflected off of, or passed through, them. Mirrors and lenses come in many different types.
Convex Mirrors
Convex mirrors reflect light from the outside of a spherical surface. They produce a smaller, seemingly distant version of reflected images and provide a wide angle of view. An example is a car's side rear-view mirror.
Concave Mirrors
Concave mirrors reflect light from the inside of a spherical surface. The focal point lies in front of the mirror. If the viewer is well behind the focal point, he or she sees a small, inverted reflection of him- or herself that grows in size as he or she gets closer. If the viewer is between the focal point and the mirror, he or she sees a magnified, right-side-up reflection of him- or herself. An example is a makeup mirror.
Cylindrical Mirrors
These mirrors reflect light from the outside of a cylinder. Much like a convex mirror, the reflection is smaller and more distant than the object, except only along one dimension. Along the dimension parallel to the axis of the cylinder, there are no distortions.
Biconvex Lenses
A biconvex lens consists of two convex surfaces (like the outside of a sphere) back to back. An object viewed through the lens appears small and inverted. The lens in your eye is a biconvex lens. If the object lies between the focal point and the lens, a viewer on the other side will see a magnified, right-side-up image of the object. Magnifying glasses use this principle.
Biconcave Lenses
A biconcave lens is the opposite of a biconvex lens. It consists of two concave surfaces (like the inside of a sphere) back to back. It is thicker along the outside than at the inside. A viewer examining an object through such a lens will see a small, right-side-up image of the object that appears closer than it actually is.
Plano-Convex Lenses
A plano-convex lens has a convex surface on one side and a flat plane surface on the other. It works in the same way as a biconvex lens, except that the light rays are bent at one surface instead of two.
Plano-Concave Lenses
A plano-concave lens has a concave surface on one side and a flat plane surface on the other. It works in the same way as a biconcave lens, except that the light rays are bent at one surface instead of two.
Convex-Concave Lenses
A convex-concave lens (also called a meniscus) has one concave and one convex surface. The distortion of one lens is countered by the distortion of the other. The relative curvature of the two surfaces affects the precise way the final image appears through the lens, with a wide range of possibilities. This is the kind of lens used in eyeglasses.
Tags: biconvex lens, focal point, light from, mirrors reflect, mirrors reflect light, reflect light, reflect light from
