Party Gel

Technical Details

Professional color gels are made of heat-resistant polycarbonate with a melting point of 267°C or polyester with a melting point of 255°C. Lee Filters offers 241 standardized colors, Rosco 315 different shades. The gels are supplied in standard sizes of 53x61 cm (21"x24") or 61x122 cm (24"x48"). Transmission values vary depending on color intensity between 5% (Deep Blue) and 85% (Light Straw). CTB filters (Color Temperature Blue) convert 3200K artificial light to 5600K daylight, CTO filters (Color Temperature Orange) vice versa.

History & Development

In 1934, Frederick Lee developed the first colorfast lighting filters for theaters in London. Rosco followed in 1952 in New York with its own formulations. In 1976, Lee introduced the numbering system that is still valid today (L201-L299 for CTB series, L204 for Full CTB). Digital cinematography since 2000 has reduced the importance of color conversion filters, as white balance can be done electronically.

Practical Use in Film

In "Blade Runner" (1982), Jordan Cronenweth used Lee 200 Double CTB to create the iconic bluish neon atmosphere. "Her" (2013) utilized CTO filters for warm interiors as an emotional contrast to cool exterior shots. For night shots, Lee 071 Tokyo Blue or Rosco 80 Primary Blue are often used to simulate moonlight. Disadvantages: Light loss of 50-95% depending on color saturation, heat development can damage the gels, time-consuming changes during shooting.

Comparison & Alternatives

LED panels with RGB control are increasingly replacing classic tungsten spotlights with color gels, offering stepless color mixing without light loss. Dichroic filters reflect unwanted wavelengths instead of absorbing them, but are 20 times more expensive. HMI spotlights with daylight characteristics (5600K) do not require CTB conversion. Color gels remain standard for cost-sensitive productions and for special effect colors that LED technology cannot reproduce.