T12

Overview

T12 is not a brand-specific lamp but a standardized form factor designation for tubular fluorescent lamps. The abbreviation follows the internationally common fluorescent tube nomenclature: the T stands for "tubular," and the number indicates the tube diameter in eighths of an inch. T12 therefore means 12/8 inches, which corresponds to 1.5 inches or approximately 38 mm in diameter. Hence, the alternative designation T38 is also common.

In film and TV lighting, T12 is the classic, comparatively thick tube format on which the well-known Kino Flo lights are based. These film tubes are color-optimized (high color rendering index, adapted to the spectral sensitivity of film and digital sensors) and are available as daylight and tungsten variants – distinguishing them from standard household or industrial tubes of the same form factor.

Technical Data

Verifiable key data for the T12 form factor and film-typical Kino Flo tubes:

Note: T12 exclusively describes the diameter, not length, base, wattage, or color. Specific watt and lumen values depend on the individual tube and length.

Set Usage

T12 fixtures provide soft, easily controllable light and are often used as fill light, for even surface illumination, in confined sets, or as practical light sources. Since the tubes remain cool during operation, they can be positioned close to talent or the subject.

Closely associated with the term is the T12 Lamp Holder – a grip accessory that allows individual T12 tubes (e.g., Kino Flo or Quasar Tubes) to be mounted outside their original housing. Such holders are available in single, dual, and quad versions; they grip the tube via clamps and terminate in a 5/8-inch baby pin (16 mm spigot) that plugs into a grip head or a stand mount. This allows bare tubes to be freely integrated into the set, hidden, or rigged as light strips.