Abstract: An optical system useful in lighting fixtures for uniformly illuminating large areas, includes a plurality of reflectors situated about a light source to cause light emitted by the light source to be concentrated in a first directional range measured from downward vertical, and to provide decreasing intensity of projected light with changes in the angle of projection from the first directional range to downward vertical. In one preferred form, four reflectors, each being a surface of revolution and spaced from the others to preclude any horizontal overlap, are utilized to concentrate the light emitted into a first directional range of about 65 degrees to 75 degrees. All of the light directed into this first directional range is either singly or doubly reflected. Unreflected light passes between a lower reflector and a central reflector to illuminate a middle directional range, and singly reflected light, which is redirected by a portion of an upper reflector, fills a lower directional range.