aberration

(noun)

The convergence to different foci, by a lens or mirror, of rays of light emanating from one and the same point, or the deviation of such rays from a single focus; a defect in a focusing mechanism that prevents the intended focal point.

Related Terms

Examples of aberration in the following topics:

  • Aberrations

    • A chromatic aberration, also called achromatism or chromatic distortion, is a distortion of colors .
    • This aberration happens when the lens fails to focus all the colors on the same convergence point .
    • A comatic aberration, or coma, occurs when the object is off-center.
    • These aberrations can cause objects to appear pear-shaped.
    • Spherical aberrations are a form of aberration where rays converging from the outer edges of a lens converge to a focus closer to the lens, and rays closer to the axis focus further.

  • Combinations of Lenses

    • The use of multiple elements allows for the correction of more optical aberrations, such as the chromatic aberration caused by the wavelength-dependent index of refraction in glass, than is possible using a single lens.
    • In many cases these aberrations can be compensated for to a great extent by using a combination of simple lenses with complementary aberrations.
    • An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration.
    • The lens elements are mounted next to each other, often cemented together, and shaped so that the chromatic aberration of one is counterbalanced by that of the other.
    • (a) Chromatic aberration is caused by the dependence of a lens's index of refraction on color (wavelength).

  • The Telescope

    • The potential advantages of using mirrors instead of lenses were a reduction in spherical aberrations and the elimination of chromatic aberrations.
    • With the invention of achromatic lenses in 1733, color aberrations were partially corrected, and shorter, more functional refracting telescopes could be constructed.

  • Adding velocities

    • This is the aberration equation.

  • Air Wedge

    • To minimize image aberrations of the resulting fringes, the angle plane of the glass wedges has to be placed orthogonal to the angle plane of the air-wedge.

  • The Compound Microscope

    • The advantages of these microscopes, due to the multiple lenses, are the reduced chromatic aberrations and exchangeable objective lenses to adjust magnification.

  • Thin Lenses and Ray Tracing

    • A thin lens is defined to be one whose thickness allows rays to refract, as illustrated in , but does not allow properties such as dispersion and aberrations.

  • The Lensmaker's Equation

    • Lenses have the same focal length when light travels from the back to the front as when light goes from the front to the back, although other properties of the lens, such as the aberrations are not necessarily the same in both directions.