E27 screw base (27 mm diameter) standard household bulb socket used as practical lighting sources in filmmaking.
Technical Details
The E27 screw thread has an outer diameter of 27 mm, a pitch of 3.5 mm, and a total height of 9.5 mm. The electrical contacts consist of the central base contact for the positive pole and the threaded body as the negative pole. In addition to E27, there are variants E14 (14 mm, "candle"), E40 (40 mm, industrial lamps), as well as the American Medium Screw Base (26 mm) and Mogul Base (39.3 mm). The maximum load capacity is 230V and typically 60-100 watts, although modern LED light sources extend these limits due to lower power consumption.
History & Development
In 1879, Edison developed the screw thread principle for his carbon filament lamp and standardized it in 1881 as "Edison Screw." International standardization was achieved in 1909 by the IEC as the E27 standard. While the slightly different Medium Base system dominates in the USA, E27 established itself in Europe and large parts of the world. The introduction of halogen (1960s), energy-saving (1980s), and LED light sources (2000s) expanded the application possibilities while maintaining the same base technology.
Practical Use in Film
Edison connectors are primarily used for set decoration: table lamps, floor lamps, and pendant lamps as practical light sources within the frame. Gaffers use commercially available halogen spotlights with E27 bases for quick fill light or as eye lights. In "Blade Runner 2049" (2017), Roger Deakins used modified household lamps with dimmed Edison bulbs for warm practicals in the apartment scenes. The advantage lies in universal availability and ease of use, the disadvantage in limited light output and restricted color temperature control.
Comparison & Alternatives
Compared to professional lamp bases like G22 (2000W-5000W HMI) or GY16 (halogen studio lights), E27 offers limited power. CEE connectors (camping/industrial) allow for higher currents but require special wiring. Modern LED panels with V-mount batteries are increasingly replacing Edison-based solutions in mobile productions. While bayonet connectors (B22) dominate in Great Britain, E27 remains the European standard for set practicals and smaller lighting tasks.