Fluorescent tubes producing continuous, cool light — energy-efficient, but prone to color casts and flicker at incorrect frequencies.
Technical Details
Film-ready fluorescent lights operate with electronic ballasts (EVG) at frequencies above 20kHz to avoid flicker. Standard tubes have diameters of T8 (26mm) or T5 (16mm) with lengths from 60cm to 150cm. The Color Rendering Index (CRI) for high-quality Kinoflo lamps reaches values above 95. Full-spectrum fluorescent tubes cover the entire visible range from 380-780nm, while daylight tubes primarily operate in the blue spectrum (450-490nm) and warm white tubes in the red range (620-750nm).
History & Development
General Electric introduced the first commercial fluorescent tube in 1938. In 1985, Frieder Hochheim developed the first flicker-free Kinoflo systems for the film industry, after conventional fluorescent lamps caused exposure problems due to the 50Hz mains frequency. In 1992, the first dimmable fluorescent lights came onto the market. Since 2010, LED panels have increasingly replaced classic fluorescent tubes, but continue to offer the characteristic large-area, soft light quality.
Practical Use in Film
Kinoflo banks with 2ft, 4ft, or 6ft tubes produce soft, low-shadow light for interviews and beauty shots. In "Her" (2013), Hoyte van Hoytema used fluorescent light for the sterile office atmosphere, while in "The Matrix" (1999), greenish fluorescent tubes characterized the virtual reality. Practical fluorescent tubes on sets are replaced by flicker-free variants or simulated by LED tubes with frequencies of 25,000Hz+. The uniform light distribution makes elaborate diffusion unnecessary.
Comparison & Alternatives
Compared to tungsten light, fluorescent lamps generate 75% less heat for the same light output. LED panels are increasingly replacing fluorescent tubes, but only since 2015 have they achieved comparable CRI values above 95. Plasma lights offer similarly soft light but require high-frequency generators. HMI lamps provide higher light output but create hard shadows without diffusion. Modern OLED panels achieve the broad light characteristic of fluorescent lamps with a significantly shallower profile.