Shield

Shields are used to minimize light trespass onto adjacent areas. A shield is an internal or external opaque structure that obstructs the backward, forward, or side light distribution in a specific solid angle produced by the shield angle and azimuth. A house-side-shield (HSS) prevents some amount of high angle light from spilling backward behind the luminaire. A front-side-shield (FSS) prevents some amount of high angle light from being emitted towards the street-side. A cul-de-sac-shield (CSS) prevents some amount of high angle light from spilling backwards and sideways. Other shield types may be offered by manufacturers – such as left-side-shields (LSS) and right-side-shields (RSS) – that do not qualify for efficacy allowances.