lampholder the socket into which a lamp fits. Not to be confused with lamp base, which is the pattern of the lampholder. lamphouse the portion of the lantern (usually in the context of higher-powered profiles) which contains the lamp, reflector, flat/peaky adjustment and possibly a condensor lens. lantern generic term for any lighting instrument. The use of lamp in this context is to be avoided, since a lamp is merely the light source within the optical and mechanical assembly that is the lantern itself. Leatherman brand of multi-use tool. See also Gerber lens transparent material (usually glass) with one or both sides curved, used to concentrate or disperse rays of light, and focus them on a distant object. lenstube the part of a modular lantern (usually a profile) which houses the lenses, and is fixed to the lamphouse to form a complete lantern. LES Lilliput Edison Screw. The smallest in the family of Edison Screw lamp bases, at only 5mm diameter. Used in low-voltage signal lamps. See also ES, MES, GES, SES limelight in the limelight: the primary focus of lighting on stage. Originates from when followspots used a block of lime, heated until it incandesced, as their light source. loom bundle of cables taped together to make them easier to handle. low smoke ordinary glycol-based smoke from a smoke machine which has been chilled to cause it to hang near the floor, giving an effect similar to that achieved when using dry ice. lumen unit of luminous flux. One lumen equals 1.471mW of radiant power at 555nm luminance luminous intensity per unit area projected in a given direction. Measured in candela per square metre luminous flux visible power, or light energy per unit time. Measured in lumens luminous intensity luminous flux per solid angle, either emitted or reflected from a point. Measured in lumens per steradian, or candela. lux unit of illuminance