British term for a 10K fixture — a high-output fresnel or open-face unit running 10,000 watts, used to light large sets or simulate sunlight through windows.
Technical Details
The Tenner operates with a 10,000-watt tungsten halogen lamp in a Fresnel lens system or as an open face fixture. The operating voltage is 120V or 220V, with a power consumption of approximately 83 amperes (120V) or 45 amperes (220V) respectively. The fixture features an adjustable spot-flood range, typically from 10° to 60° beam angle. The housing is made of heat-resistant aluminum with ventilation slots, and the total weight ranges from 25 to 35 kilograms. Common models include the Arri T10 or the Mole-Richardson 10K Senior.
History & Development
Tensors emerged in the 1960s when the film industry required more powerful light sources for large productions. Mole-Richardson developed the first commercial 10K fixture for Hollywood studios in 1963. Arri followed in 1971 with the T10, which set European standards with its more compact design. With the introduction of HMI lamps in the 1970s, Tensors lost importance, as 6K HMI lights provided more light with lower power consumption.
Practical Use in Film
Tensors are used as key lights for wide shots or for the base illumination of large sets. In "Lawrence of Arabia" (1962), Freddie Young used several 10K tungsten fixtures for the nighttime desert scenes. Stanley Kubrick used modified Tensors for "Barry Lyndon" (1975) to enhance the candlelight aesthetic. The high power consumption requires separate circuits and professional electrical installation. The heat output of approximately 8,500 watts necessitates extensive ventilation on set.
Comparison & Alternatives
Modern LED panels like the Arri SkyPanel S360-C achieve similar light levels to a 2K tungsten with 400 watts, but do not replace the raw light output of a Tenner. HMI fixtures like the Arri M90 (9K HMI) deliver daylight quality at 8,000 watts and are three times more efficient than Tensors. Tensors remain indispensable when warm tungsten light at maximum intensity is required, such as for period pieces or special mood lighting.