Abstract: A light intensifier for increasing the useful light output of relatively inefficient light fixtures by providing a diffusing light reflector which extends about the light therein. The reflector can be ribbed so that it can be adjusted to fit within the existing inefficient fixture and can be constructed from foil, metalized mylar or other similar materials with a heat tolerant, electrically insulating backing. Insulated perforations may be included so that the reflector can be adjusted in size without danger of inducing an electrical short circuit.