Minus Green is a technique of professional lighting design.
Technical Details
Minus Green filters are made of colored glass or film with precise spectral transmission. Standard filter strengths are CC05, CC10, CC15, CC20, and CC30, with CC30 absorbing approximately 30% of green wavelengths. The filters simultaneously reduce the overall light quantity by 0.3-1 stops depending on the strength. High-quality versions from manufacturers like Tiffen or Lee Filters ensure uniform color distribution across the entire filter surface. Available as screw-in filters, matte box inserts, or large-format gels for lighting fixtures.
History & Development
Systematic color correction developed in the 1930s with the introduction of the Technicolor process. Minus Green filters emerged in the 1950s in response to the increasing prevalence of fluorescent lighting indoors. Kodak standardized the CC system in 1963 for uniform evaluation of correction filters. With digitalization since 2000, software has partially taken over color correction, yet optical filters remain indispensable for high-quality productions as they ensure more natural skin tones already during recording.
Practical Application in Film
Classic use occurs in office buildings, hospitals, or schools with fluorescent tube lighting. Cinematographer Roger Deakins used Minus Green filters in "Blade Runner 2049" (2017) to correct mixed light sources in laboratory sequences. For daylight shots through windows with interior fluorescence, a CC20-30 filter compensates for the green cast. Modern LED panels also produce green shifts, which CC10-15 filters compensate for. The filter enables natural skin tones without complex post-production corrections, which often lead to color banding.
Comparison & Alternatives
Distinction from Plus Green filters, which specifically add green, and from general daylight/tungsten conversion filters (CTB/CTO). Digital color correction in DaVinci Resolve or Avid offers more flexible adjustments but requires more processing power and can create image artifacts with extreme corrections. High-quality LED systems like ARRI SkyPanel feature built-in green-magenta adjustment, but do not replace optical filtering for mixed light sources.