Abstract: A device, such as a flashlight, spotlight, or reading light, for emitting an incident beam of light wherein the intensity and color of an incident beam of light emitted from the device can be manually modulated or adjusted. The device utilizes a variable density filter system which is manually adjustable and which incorporates a pair of optical linear polarizing filters or lenses which are mounted so that the emitted beam of light must pass through the polarizing filters. The filter system is adapted to produce at one extreme a high transmittance value when the axes of the polarizing filters are parallel. At the opposite extreme a very high extinction density is achieved when the axes of the polarizing filters are oriented so as to be essentially normal or perpendicular with each other. Varying optical densities are produced at settings between these two extremes.