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  • concave mirror

    reflects light from its inwardly curving surface, the edges of which curve toward the observer; can produce either an upright, virtual image or an inverted, real image

    convex mirror

    the edges curved away from the observer that reflects light from its outwardly curving surface; produces an upright, reduced, virtual image

    diffuse reflection

    a scattered, fuzzy reflection produced by a rough surface

    focal length

    distance between the focal point and the mirror or lens

    focal point

    point where incident light rays that are parallel to the principal axis converge after reflecting from a mirror or refracting through a lens


    optical reproduction of an object formed by the combination of light rays reflected or refracted by an optical device


    amount that an image is enlarged or reduced in size, relative to the object


    luminous or illuminated source of light rays

    plane mirror

    flat, smooth surface from which light is reflected by specular reflection, producing a virtual image that is the same size as the object, has the same orientation, and is the same distance from the mirror as the object

    principal axis

    straight line perpendicular to the surface of a mirror or lens that divides the mirror or lens in half

    real image

    optical image that is formed by the converging of light rays

    specular reflection

    reflection produced by a smooth surface in which parallel light rays are reflected in parallel

    spherical aberration

    image defect of a spherical mirror or lens that does not allow parallel light rays far from the principal axis to converge at the focal point and produces an image that is fuzzy, not sharp

    virtual image

    image formed of diverging light rays

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