The present disclosure describes light delivery and distribution components of a ducted lighting system having a cross-section that includes planar duct portions, and a light source. The delivery and distribution system (that is, light duct and light duct extractor) can function effectively with any light source that is capable of delivering light which is substantially collimated about the longitudinal axis of the light duct, and which is also preferably substantially uniform over the inlet of the light duct.