Early-1940s Wabash Superflood N.B2 (120 V 500 W)

The Superflood N.B2 is a photographic lamp made by the Wabash Photolamp corporation, a subsidiary of the Wabash Appliance Corp, a small manufacturer of specialty incandescent lamps established in Brooklyn, New York, around 1936. That company, known in particular for its blackout lamps produced during World War II, was eventually acquired in 1944 by Sylvania Electric Products as the latter expanded into photographic and specialty lighting, at which point the Wabash brand disappeared.

The special lamp shown here was manufactured during the war, before the Sylvania acquisition, and is designed for the maximum production of actinic light suitable for the exposure of photographic film. To that end the tungsten filament is overdriven and the lamp is built with a cobalt blue glass bulb that has a higher ultraviolet transmission than the standard soda lime glass used in classical GLS lamps. The N.B2 reference is a manufacturer-specific code, with N referring to “natural” light (as opposed to the warm color of unfiltered incandescent light), and B2 corresponding to a “blue color correction” of the second type, likely specific to this 500 W lamp. Such code enabled a quick identification and ensured that correct lamp types were used for specific lighting requirements.

Except for the two special design features mentioned earlier, the Superflood N.B2 has a standard GLS construction with a PS-shaped bulb filled with an argon-nitrogen mix, and is fitted with a E26 end cap and can be run directly on the American 120 V mains. This enabled its use in standard flood luminaires to illuminate the subject to be photographed. However, its short service life of ~6 h meant that it was used briefly and intermittently only, the price for the high performances of its overdriven incandescent radiator. The latter, combined with the blue glass bulb, result in a light output of ~10.5 klm, about 18 % more than that of the standard 500 W GLS lamp. This figure is impressive given the heavy optical filtering needed to raise the light color temperature to 4800 K (CRI of 95+ R8).