1985 Sylvania FND Red (12 V 50 W)

Sylvania’s early colored dichroic MR16 lamps are interesting for the fact that it is their primary multilayer mirror which is tuned to reflect a desired light color while transmitting the complementary color. The company made four different lamps of such kinds and this FND is designed to project a red light beam forward while the complementary cyan light is transmitted towards the back side of the lamp. Given that the light spectrum emitted by the incandescent tungsten-halogen source is rich in red, the mirror's spectral cutoff is set around 600 nm to ensure a sufficiently rich red light color. The resulting complementary spectrum contains all other colors, from violet to yellow-orange, thus causing in the washed out cyanish light color at the back of the lamp.