Glossary#

Φ Radiant (Luminous) Power or Flux

Units are W (or lumens, lm)

I Radiant (Luminous) Intensity

I = Power / Solid Angle

M Radiant (Luminous) Emittance or Exitance

M = Power/ Unit Area of a source

E Irradiance (Illuminance)

Same as M, but for a receiving area.

L Radiance (Luminance)

Characterizes a source.

  • Focal Length

  • Diopter

  • Magnification

  • Virtual and real images

  • Field of view (FOV)

  • Depth of focus

  • Depth of field

  • Throw

  • Aperture stop

  • Field stop

  • Pupils (entrance and exit)

  • Principal planes

  • Effective focal length (EFL)

  • Back focal length (BFL)

  • Front focal length (FFL)

  • Numerical aperture

  • F#

  • Intensity

  • Irradiance

  • Power

  • Accommodation

  • Abbe number

  • Vignetting

  • Ray fans (Ray intercept plots)

  • Field angles

  • Spot diagrams

  • Merit function

  • Airy disk

  • Optical path difference (OPD)

  • Point spread function (PSF)

  • Modulation transfer function (MTF)

  • Strehl ratio