An optical warning system comprises a light head that includes a light source emitting light rays from a light-emitting area. The light rays propagate through an optical diffuser to provide a visual warning signal to an observer remotely located from the optical warning system. A Fresnel optic array positioned between the optical diffuser and the light-emitting area is spaced apart from and spatially aligned with the light-emitting area to receive the light rays emitted from the light-emitting area and form a collimated light beam. The Fresnel optic array is fabricated so that it exhibits increased optical transmission efficiency by reducing light lost to scattering in forming the collimated light beam.