Abstract: Optical systems capable of use in a variety of lighting applications particularly including industrial high bay and similar applications, the systems of the invention deliver energy efficient and effective light distribution through use of dual reflector arrangements wherein an inner reflector having a divergent and convergent profile is stationary relative to a lamp to form an inner reflector/lamp assembly, a prismatic outer reflector being displaceable relative to the inner reflector/lamp assembly to produce differing photometric distributions.