Tungsten Film
Encyclopedia
Tungsten film is photographic film
designed to accurately represent colors as perceived by humans under tungsten
light; the more usual color films are "daylight films", balanced to produce accurate colours under direct light from the sun or electronic flash. Tungsten film was developed for photographers who use tungsten lights, also known as photofloods
, which have a much lower color temperature
than daylight, at 3200 kelvin
s. It also renders colors more accurately than daylight film under ordinary household incandescent lighting.
On daylight-balanced film tungsten lighting produces a spectrally accurate rendition of a scene; but human vision adjusts to the color of the lighting and perceives colors as if under daylight, seeing a spectrally accurate image as having a yellow-orange cast. Tungsten film is balanced in such a way that this lighting is recorded with a subjectively neutral color balance. When shot outdoors, tungsten film produces a strong blue cast, an effect which is often used purposely to create different color contrasts. In the motion picture industry the use of underexposed tungsten-balanced film in an outdoor setting is a common way of producing a "day for night
" effect, whereby film shot during the daytime looks as if it had been shot at night.
Tungsten slide films are designed to provide accurate exposure as well as color rendition even when exposed according to exposure meter readings indicating a long exposure; tungsten film can be used to avoid reciprocity failure which often occurs when using long exposures. Common film speed
s for tungsten-balanced slide film are ISO 64, 160, and 320.
Photographic film
Photographic film is a sheet of plastic coated with an emulsion containing light-sensitive silver halide salts with variable crystal sizes that determine the sensitivity, contrast and resolution of the film...
designed to accurately represent colors as perceived by humans under tungsten
Tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...
light; the more usual color films are "daylight films", balanced to produce accurate colours under direct light from the sun or electronic flash. Tungsten film was developed for photographers who use tungsten lights, also known as photofloods
Incandescent light bulb
The incandescent light bulb, incandescent lamp or incandescent light globe makes light by heating a metal filament wire to a high temperature until it glows. The hot filament is protected from air by a glass bulb that is filled with inert gas or evacuated. In a halogen lamp, a chemical process...
, which have a much lower color temperature
Color temperature
Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, and other fields. The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of...
than daylight, at 3200 kelvin
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
s. It also renders colors more accurately than daylight film under ordinary household incandescent lighting.
On daylight-balanced film tungsten lighting produces a spectrally accurate rendition of a scene; but human vision adjusts to the color of the lighting and perceives colors as if under daylight, seeing a spectrally accurate image as having a yellow-orange cast. Tungsten film is balanced in such a way that this lighting is recorded with a subjectively neutral color balance. When shot outdoors, tungsten film produces a strong blue cast, an effect which is often used purposely to create different color contrasts. In the motion picture industry the use of underexposed tungsten-balanced film in an outdoor setting is a common way of producing a "day for night
Day for night
Day for night, also known as nuit américaine , is the name for cinematographic techniques used to simulate a night scene; such as using tungsten-balanced rather than daylight-balanced film stock or with special blue filters and also under-exposing the shot to create the illusion of darkness or...
" effect, whereby film shot during the daytime looks as if it had been shot at night.
Tungsten slide films are designed to provide accurate exposure as well as color rendition even when exposed according to exposure meter readings indicating a long exposure; tungsten film can be used to avoid reciprocity failure which often occurs when using long exposures. Common film speed
Film speed
Film speed is the measure of a photographic film's sensitivity to light, determined by sensitometry and measured on various numerical scales, the most recent being the ISO system....
s for tungsten-balanced slide film are ISO 64, 160, and 320.