FKW

Overview

FKW is an ANSI lamp code – not a manufacturer or a type of luminaire, but a standardized three-letter designation from the American National Standards Institute for a specific light source. The code specifies wattage, voltage, color temperature, base, bulb shape, and burning position across manufacturers. An FKW lamp from OSRAM, GE, or another manufacturer is therefore interchangeable in its crucial specifications.

FKW designates a single-ended tungsten-halogen lamp (Tungsten/Quartz) with 300 watts for 120V mains in North America. It is the classic light source for compact 300W Fresnel luminaires and is tungsten-balanced (3200 K). In addition, mains-powered 220/230V variants exist for European use; the OSRAM/GE proprietary factory designation for the type is CP81.

Technical Data

Luminous flux and average lifespan are specified slightly differently by manufacturers (around 6900–7800 lm with approx. 50–200 hours of life), depending on the brand and version.

On-Set Usage

FKW is the standard light source for many 300W Fresnel luminaires and is therefore found in almost every lighting inventory. Typical fixtures include:

• ARRI Junior 300 / ARRI 300 Plus (Fresnel)
• Mole-Richardson Betweenie (300W Fresnel/Solarspot)
• Altman 300L "Proline"
• LTM Pepper 300
• DeSisti Magis 300

As with all halogen lamps: do not touch with bare fingers (grease from skin causes localized overheating and premature failure), let the lamp cool down before changing, and pay attention to the correct burning position. The 3200 K typical for tungsten light must be adjusted for daylight scenes using a conversion filter (e.g., CTB) or white balance.