The Castor 270, often referred to as the Strand Century Castor 270, is a classic, high-output ellipsoidal reflector spotlight (ERS) designed for theatrical, television, and studio applications. As a fixture in the renowned Strand Century line, it is engineered to deliver a bright, controllable beam of light using a 2000-watt (2kW) tungsten-halogen lamp. Its optical system, featuring an adjustable lens tube and a four-blade framing shutter system, allows for precise beam shaping, hard-edge cuts, and pattern projection via gobos, making it a versatile workhorse for key, back, and special effect lighting. The fixture's robust, cast aluminum housing is built to withstand the rigors of professional use, including extensive touring and permanent installation.

The Castor 270's design prioritizes optical performance and flexibility. It accepts a range of interchangeable lens tubes to provide different field angles, and its gate can accommodate both "A" and "B" size gobos for creating textures and logos. The fixture includes a focus mechanism that adjusts from a sharp, defined beam to a soft field, and the framing shutters can be rotated and positioned independently to mask off specific areas of the stage. While it requires significant power and generates substantial heat, its output and quality of light have made it a standard in the industry for decades, particularly in large theaters, opera houses, and film studios where powerful, focused light is essential.

Though increasingly supplemented or replaced by more energy-efficient LED fixtures, the Castor 270 remains a symbol of professional theatrical lighting. Its combination of brute output, precise optical control, and mechanical durability has cemented its legacy as a reliable tool for lighting designers who need uncompromising intensity and versatility in a traditional profile spot.