[As used in this article, the following words and terms shall have the meaning ascribed thereto:]
Cutoff angle (of a luminaries):The angle, measured up from the nadir, between the vertical axis and the first line of sight at which the bare sources is not visible.
Footcandle:A unit of luminance amounting to one lumen per square foot.
Full cut-off type fixture:A luminaries or light fixture that, by design of the design of the housing, does not allow any light dispersion or direct glare to shine above a 90-degree, horizontal plane from the base of the fixture. Full cut-off fixtures must be installed in a horizontal position as designed, or the purpose of the design is defeated.
Fully shielded:A fully shielded luminaries is a luminary constructed or shielded in such a manner that all light emitted by the luminaries, either directly from the lamp or indirectly from the luminaries, is projected below the horizontal plane through the luminaries' lowest light emitting part as determined by photometry test or certified by the manufacturer. Fixtures will be installed in a horizontal position as designed, or disability glare will result.
Glare:The sensation produced by luminance within the visual field that is sufficiently greater than the luminance to which the eyes are adapted to cause annoyance, discomfort, or loss in visual performance and visibility.
Light trespass:Light emitted by a lighting installation, which falls outside the boundaries of the property on which the installation is sited.
Luminance:The quantity of light, or luminous flux, arriving at a surface divided by the area of the illuminated surface, measured in lux or footcandles.
Luminance:The physical quantity corresponding to the brightness of a surface (e.g. a lamp, luminaries, sky, or reflecting material) in a special direction. It is the luminous intensity of an area of the surface divided by that area. The unit is candela per square meter.
Luminaries:A complete lighting unit consisting of a lamp or lamps together with the parts designed to distribute the light, to position and protect the lamps and to connect the lamps to the power supply.
Lux (lx):The SI unit of illuminates. One lux is one lumen per square meter.
Obtrusive light:Spill light which, because of quantitative, directional or spectral context, gives rise to annoyance, discomfort, distraction or a reduction in the ability to see essential information.
Spill light:Light emitted by lighting installation that falls outside the boundaries of the property on which the installation is sited.
Up lighting:Any light source that distributes illumination above a 90-degree horizontal plane.
(Ordinance 1176, § 1, 4-24-01)