Infrared Photography
International · Infrared Film 1910–present
Film that records light the eye cannot see. Foliage turns white, skies turn black, skin turns waxy and translucent, and the result looks less like a photograph of a place than like a photograph of a different planet.
Origin
Infrared-sensitive emulsions were developed in the 1910s and used first for scientific and military purposes — haze penetration in aerial reconnaissance, since infrared cuts through atmospheric scatter that blocks visible light. Kodak's High Speed Infrared became available to photographers and was adopted for landscape and portraiture. It was discontinued in 2007; Rollei, Ilford and others produce extended-red films, and digital sensors can be converted by removing their internal infrared-blocking filter.
Technique
The emulsion is sensitised into the near infrared, around 700 to 900 nanometres. A deep red or opaque visually-black filter is fitted to block visible light, so the photographer is composing through a filter they cannot see through and metering is largely a matter of experience and bracketing. Infrared focuses at a different point from visible light, so lenses carry a separate infrared focus mark and the focus must be shifted manually after composing. The film had to be loaded and unloaded in total darkness, because the felt light trap of a 35mm cassette does not block infrared.
The palette
A systematic inversion of expected values. Chlorophyll reflects infrared strongly, so healthy foliage renders brilliant white — the Wood effect, named for Robert Wood, who first photographed it in 1910. Clear sky reflects almost none and goes black, so clouds stand out with extreme drama. Water is black. Skin becomes pale, smooth and slightly translucent, with veins sometimes visible through it, and freckles and blemishes disappear entirely. In false-colour infrared film, used for aerial survey, the shift is mapped to visible dyes and vegetation comes out magenta.
Legacy
Its scientific applications remain central — vegetation health monitoring from satellites, medical imaging, and the examination of paintings, where infrared reflectography reveals underdrawing beneath the paint layers and has transformed the study of half the artists in this atlas. That last use is a neat closing of the circle: a photographic process that exists to show what is underneath a painting.
Palette
The colours reconstructed for this artist, with the reasoning behind each.
Pigments used: Silver