Color gel
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A color gel or color filter (
Gels have a limited life, especially in
In permanent installations and some theatrical uses, colored glass filters or
History
In
By 1945 more heat-tolerant and self-extinguishing
The acetate-based material was replaced by
Often a surface coating was applied on a transparent film. The first dyed polyester gels were introduced by Berkey Colortran in 1969 as Gelatran, the original deep-dyed polyester.[3] The Gelatran process is still used today to produce GAMColor (100% of the line) and Roscolux (about 30% of the line).[4] Other color manufacturers, such as Lee Filters and Apollo Design Technology, use a surface applied dye. (Roscolux is 70% polycarbonate and 30% deep-dyed polyester.)
Almost every color manufacturer today uses either polycarbonate or polyester to manufacture their gels. Even today's gels can burn out (to lighten in color starting in the center) easily, rendering them useless. As instrument design improves, it has become a selling point on many lights to have as little heat radiating from the front of the fixture as possible to prevent burn-through, and keep stage equipment and actors cooler.
In the 1930s, Strand Electric of London provided the first numbering system for their swatches and with their agents in New York and Sydney the numbering system went round the world. Remnants of this original filter color system exist in the color swatches of today (such as Deep Amber = No. 3; Primary Red = No. 6; Middle Rose = No. 10; Peacock Blue = No. 15; Primary Blue = No. 20; Primary Green = No. 39).
In the theater, gels are typically available in single 20 in × 24 in (500 mm × 600 mm) sheets, which are then cut down to the appropriate size before use. The size originates from the gelatin days: it is the same as a standard baker's sheet, which was used to cast the sheets. In the film industry, gels are usually cut straight from rolls 24 or 48 in (600 or 1,200 mm) wide and 50 ft (15 m) long, as the size required may vary from a single practical halogen spotlight in a ceiling to a whole window.
Colors
Similar colors may vary between different companies' formulations. For example, many have a color named "
By necessity color gels are selected by specifying the manufacturer, line, color number, and name: Rosco Cinegel #3202 Full Blue CTB.
Apollo Design Technology uses a four digit number based on the visible spectrum to designate and locate specific color transmissions.
The GAMColor line from Rosco employs a three digit numbering system, organized by the wavelength of the principle color in the family, i.e.: Blues in the 800's with primary blue at 850 (though the manufacturer's numbers do not relate directly to any wavelength, transmission, or frequency). The same applies to Greens in the 600's, Reds in the 200's, etc.
Rosco's Roscolux line is currently the oldest major line of color media, . They started using only a two-digit numbering system, listing colors in no particular order. As the range demanded by designers increased and many more colors were offered in the 1970's and 1980's, two digits quickly proved inadequate. As a result the original scheme was overlayed by three-digit and eventually four-digit numbers in between the original two-digit colors in the line.
Manufacturers produce swatch books, which contain a small sample of each color, along with the color name and manufacturer's catalogue number. Many manufacturers also provide spectral analysis for each color and transmission values, expressed as a percentage of light allowed to pass through the filter from the light source. Swatch books enable designers and technicians to have a true representation of the manufacturers' range of colors.
Many[citation needed] designers choose a limited color palette for generic applications because it is financially and logistically difficult to have access to all colors for a single show.
There are also gels for
Most ranges of gels also include non-colored media, such as a variety of
It is common for a gel manufacturer to publish the
See also
References
- ^ "TV, web/corporate video, film/photography studio and lighting/grip terms glossary – deStudio, Dublin". www.destudiodublin.com. Retrieved 2018-08-08.[permanent dead link]
- ^ "How to use lighting gels". www.amateurphotographer.co.uk. 8 April 2013. Retrieved 2019-03-22.
- ^ "Gel history". www.derekleffew.com. Retrieved 2019-03-22.
- ^ "GAMcolor". ca.rosco.com. Retrieved 2019-03-22.