Optical filter with fine etched lines that extend light sources into characteristic streaks, producing the classic star-burst effect on practical lamps and highlights.
Technical Details
Streak filters use diffraction gratings with 100-300 lines per millimeter, etched onto glass or optical acrylic. Standard versions produce streaks 2mm to 15mm long at an aperture of f/2.8. Variants include Blue Streak (enhances blue spectral components), Supernova (4-8 rays), Anamorphic Streak (horizontal lines), and Multi-Image Prisms (multiple light refractions). The filters are available in sizes from 77mm to 138mm for matte box systems. The effect intensifies at wide apertures and significantly diminishes at f/8.
History & Development
Tiffen developed the first commercial streak filters in 1978 as an alternative to complex optical trick effects in post-production. The filter was first prominently used in "Star Trek: The Motion Picture" (1979) for depicting the Enterprise engines. In the 1980s, the streak filter became standard for science fiction productions. Since 2010, these filters have experienced a resurgence due to the anamorphic renaissance, as they enhance the coveted "analog look" of digital footage.
Practical Use in Film
Cinematographer Michael Ballhaus used streak filters in "Goodfellas" (1990) for the nightclub sequences to atmospherically enhance artificial light. "Blade Runner 2049" (2017) combined 1/4 Blue Streak filters with practical light sources for the neon-dominated street scenes. The filter amplifies existing light sources but does not create effects without corresponding highlights in the image. Modern workflows often combine streak filters with LED panels at a 5600K color temperature for optimal light refraction. Disadvantages: Loss of contrast with heavy use and unwanted reflections in backlight shots.
Comparison & Alternatives
Streak filters differ from star filters by creating directional instead of radial rays. Pro-Mist filters produce diffuse halos without sharp lines. In post-production, similar effects can be created with plugins like Optical Flares, but without the natural light interaction of the optical filter. Anamorphic lenses create horizontal streaks as a natural side effect of their design. For practical light sources below 500 lux, streak filters remain ineffective; digital flares in color correction offer an alternative here.