Eight photographers enter the twilight zone.
“Heavenly shades of night are falling, it's twilight time,” goes the song lyric. However, twilight occurs at dawn before sunrise each morning, as well as at dusk after sunset, although its effects then occur in reverse. Its duration differs for 'astronomical', 'nautical' or 'civil' twilight. It varies from roughly 120 minutes for astronomers, who need a very dark sky to see all the stars, to 90 minutes for old-style navigators, who need see only the brightest stars to use their sextants, and 60 minutes for civilians, who need street lights when it is only moderately dark.
In Twilight: Photography in the Magic Hour, at London's Victoria and Albert Museum until 17 December, eight contemporary photographers are exhibiting around 50 works that explore the dramatic visual effects observed in the sky during twilight. Many of these effects result from the Sun's position below the horizon, which causes Earth's atmosphere to scatter more of the shorter wavelengths of light (from the blue end of the spectrum) than it does during the hours of daylight, leaving more of the longer wavelengths (towards the red end) to reach our eyes.
How we see colour depends on light levels. Photographers always have to overcome the technical limitations of cameras and film, which cannot accommodate to the low light levels and colours of twilight with the flexibility and subtlety of the human eye and brain. They can use this distortion, however, to heighten the psychological effects of twilight, and artists have long attempted to capture its alchemical qualities in oils and watercolours.
Robert Adams' Summer Nights series (1979–82) reaffirms the ability of black-and-white photography to convey the effects of twilight, tracking urban encroachment in Colorado and following its path outwards from city centres into wilderness in a narrative sequence of twilight scenes.
Other artists use the full potential of colour photography to interpret twilight, including the digital manipulation of images. In his series of untitled photographs (2000–03), Bill Henson populates the peripheries of Australian towns with posed groups of androgynous adolescents, creating an edgier twilight zone. “It is not for nothing that twilight is [Henson's] favourite time of day,” says Australian critic Peter Craven, quoted in a catalogue essay, “that time when colour still functions as an agent of definition but when it has lost the power to distract the mind with any excess of the sensuous, when everything has bled and receded.”