An apparatus for collecting sunlight and directing the collected sunlight into the interior of the building to provide illumination, so that the energy used for artificial illumination can be conserved, includes a collector, a light pipe, and a diffuser. The collector includes an immovable flared trumpet-like hollow tube having a highly reflective interior surface and having its larger aperture oriented to maximize the sunlight received at a particular time of day. The larger aperture is closed by a transparent cap which supports a secondary reflector that extends forward of the larger aperture. The secondary reflector serves to reflect into the hollow tube light travelling at a low angle of incidence with respect to the larger aperture to compensate for the reduced efficiency of the larger aperture to low-angle light. The apparatus also includes a sprinkler for washing dust and other deposits from the transparent cap, and further includes a servo-controlled light valve for maintaining, to the extent possible, a constant level of illumination at a work station within the building.