When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Cardinal point (optics) - Wikipedia

    en.wikipedia.org/wiki/Cardinal_point_(optics)

    The principal planes are crucial in defining the properties of an optical system, since the magnification of the system is determined by the distance from an object to the front principal plane and the distance from the rear principal plane to the object's image. The principal points are the points where the principal planes cross the optical axis.

  3. Optical axis - Wikipedia

    en.wikipedia.org/wiki/Optical_axis

    Optical axis (coincides with red ray) and rays symmetrical to optical axis (pair of blue and pair of green rays) propagating through different lenses. An optical axis is an imaginary line that passes through the geometrical center of an optical system such as a camera lens , microscope or telescopic sight . [ 1 ]

  4. Optic axis of a crystal - Wikipedia

    en.wikipedia.org/wiki/Optic_axis_of_a_crystal

    An optic axis is a direction rather than a single line: all rays that are parallel to that direction exhibit the same lack of birefringence. [1] Crystals may have a single optic axis, in which case they are uniaxial, or two different optic axes, in which case they are biaxial. Non-crystalline materials generally have no birefringence and thus ...

  5. Principal axis - Wikipedia

    en.wikipedia.org/wiki/Principal_axis

    Principal axis may refer to: Principal axis (crystallography) Principal axis (mechanics) Principal axis theorem; See also. Aircraft principal axes;

  6. Ray (optics) - Wikipedia

    en.wikipedia.org/wiki/Ray_(optics)

    The principal ray is both sagittal and meridional. [4] All other sagittal rays are skew rays. A paraxial ray is a ray that makes a small angle to the optical axis of the system and lies close to the axis throughout the system. [10] Such rays can be modeled reasonably well by using the paraxial approximation. When discussing ray tracing this ...

  7. Crystal optics - Wikipedia

    en.wikipedia.org/wiki/Crystal_optics

    This causes a rotation of the principal axes of the medium and alters the behaviour of light travelling through it; the effect can be used to produce light modulators. In response to a magnetic field , some materials can have a dielectric tensor that is complex- Hermitian ; this is called a gyro-magnetic or magneto-optic effect .

  8. Astigmatism (optical systems) - Wikipedia

    en.wikipedia.org/wiki/Astigmatism_(optical_systems)

    In third-order astigmatism, the tangential rays (in the tangential plane) and sagittal rays (in the sagittal plane) form foci at different distances along the optic axis. These foci are called the tangent focus and sagittal focus, respectively. In the presence of astigmatism, an off-axis point on the object is not sharply imaged by the optical ...

  9. Birefringence - Wikipedia

    en.wikipedia.org/wiki/Birefringence

    In other words, the polarization of the fast (or slow) wave is perpendicular to the optic axis when the birefringence of the crystal is positive (or negative, respectively). In the case of biaxial crystals, all three of the principal axes have different refractive indices, so this designation does not apply.