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Glossary

  • Isotropic light source: light source emitting with a constant intensity whichever the direction
  • Aperture : diaphragm limiting the number of light rays that are able to propagate
  • Optical system: in geometrical optics, assembly of optical components for redirecting the light in a controlled manner
  • Effective focal length: algebraic distance from the primary/secondary principal plane of an optical system to its front/back focal plane
  • Transmission ratio: ratio between transmitted radiation power (or intensity or amplitude) and incident radiation power (or intensity or amplitude)
  • Irradiance ( radiometry ): optical power received by unit area
  • Primary principal plane: plane of the object space of an optical system whose conjugation by the said optical system occurs with a magnification of +1 and whose conjugate plane is called the secondary principal plane