Definition and Uses
– Color gels are transparent colored materials used in theater, event production, photography, videography, and cinematography.
– They are used to color light and for color correction.
– Modern gels are made of thin sheets of polycarbonate, polyester, or other heat-resistant plastics.
– Gels are placed in front of a lighting fixture in the path of the beam.
– They have a limited lifespan, especially in saturated colors and shorter wavelengths.
History
– In Shakespearean-era theater, red wine and colored water/silk were used as light filters.
– Gelatin-based color media were used until at least 1979.
– Acetate-based filters like Roscolene were developed in the 1940s but fell out of favor due to temperature limitations.
– Polycarbonates and polyester-based filters replaced acetate-based gels.
– Dyed polyester gels were introduced in 1969 by Berkey Colortran.
Numbering and Swatches
– Strand Electric provided the first numbering system for color gels in the 1930s.
– Gels in theaters are typically available in 20in × 24in sheets, cut to the appropriate size before use.
– In the film industry, gels are cut from rolls 24 or 48in wide and 50ft long.
– Manufacturers use different numbering systems and color names, making it misleading to refer to gel colors by name.
– Swatch books are provided by manufacturers, containing samples, color names, and catalog numbers.
Color Variations
– Similar colors may vary between different companies’ formulations.
– Gel colors are specified by the manufacturer, line, color number, and name.
– Apollo Design Technology uses a four-digit number based on the visible spectrum.
– The GAMColor line from Rosco employs a three-digit numbering system organized by the wavelength of the principle color.
– Roscolux uses a two-digit numbering system that expanded to three and four digits to accommodate the increasing range of colors.
Color Correction
– Color correction gels like CTB and CTO alter or correct the color temperature of a light source.
– CTB corrects tungsten lights to match daylight negative.
– CTO corrects daylight-balanced light sources to match tungsten negative.
– There are half and quarter variations of color correction gels.
– Color correction gels are commonly used in artistic and film productions. Source: https://en.wikipedia.org/wiki/Color_gel
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A color gel or color filter (Commonwealth spelling: colour gel or colour filter), also known as lighting gel or simply gel, is a transparent colored material that is used in theater, event production, photography, videography and cinematography to color light and for color correction. Modern gels are thin sheets of polycarbonate, polyester or other heat-resistant plastics, placed in front of a lighting fixture in the path of the beam.
Gels have a limited life, especially in saturated colors (lower light transmission) and shorter wavelength (blues). The color will fade or even melt, depending upon the energy absorption of the color, and the sheet will have to be replaced. In permanent installations and some theatrical uses, colored glass filters or dichroic filters are used. The main drawbacks are additional expense and a more limited selection.
