• Incandescent Lamp

    A light source where current passes through a filament to create heat which, in turn, creates light.

  • LED (Light-Emitting Diode)

    a solid-state semiconductor device that converts electrical energy directly into light.

  • Light Output Ratio

    At Carclo Optics the LOR is determined by measuring the ratio of the light collected  after the Optic output face (excluding scattered light) and dividing this by all the light collected from the LED alone, expressed as a percentage.

  • Lightguide

    An optical component within which light is usually confined and guided by total internal reflection.

  • Lumen

    • the SI derived unit of luminous flux which is a measure of the total "amount" of visible light emitted by a source. The lumen is a photometric unit which means it is normalised according to the response of the average human eye.
  • Luminous Flux

    Luminous Flux is defined as the total electromagnetic energy emitted by the light source into a sphere (360°) surrounding the light source.

  • Luminous Intensity

    in simple terms is a measure of the amount of light (in lumens) emitted from a light source as a function of angle. The SI unit for luminous intensity is candela (i.e. lumens per unit solid-angle). Hence, the Intensity (distribution) from a light source is independent of distance.

  • MacAdam Ellipse

    This refers to the region on a chromaticity diagram in which all the colours are indistinguishable, to the average human eye.

  • Milli-Candela (mcd)

    One thousandth of a candela.

  • Multi-Chip LED

    A single LED package containing two or more LED die. The different separate die can be different colours or can be illuminated independently or together.