Abstract: A sunlight simulator includes an elongated, cylindrical housing, an artifical light source disposed along the longitudinal axis thereof, and a plurality of light collecting subassemblies equidistantly spaced radially from and around the light source. The light source is of a type that emits a substantial amount of radiation in the UV portion of the spectrum. The light collecting subassemblies provide a plurality of individually and selectively adjustable beams of UV radiation. A plurality of light guides are provided for directing the radiation to desired locations.