DAY 318

PHOTOGRAPHIC CURIOSITIES

Infrared Photography

SEEING WITH A SERPENT’S EYES

Countless Hollywood films and self-proclaimed television “ghost hunters” have introduced the image of green-colored “night vision” to the popular consciousness. Infrared photography, however, is much broader than simply seeing in the dark.

To be sure, infrared imagery is fully functional in pitch darkness. (Snakes have similar infrared sensors which allow them to see at night.) Infrared light covers a wide range of wavelengths, ranging from light that is closer to the wavelengths of visible light, known as “near infrared,” to “far infrared,” which is on the border of microwave frequency.

Rather than being reserved exclusively for nighttime use, however, infrared technology is also used to complement conventional photography. Infrared photographs are often taken in broad daylight, as they pick up details that are not always visible within the spectrum of visible light.

To the human eye, an object may blend with its background if both have the same colors and shading. A similar phenomenon occurs with infrared photography, known as “thermal crossover”—if an object has the exact same heat as its background, it can be “camouflaged” in an infrared photo. For this reason, an infrared photograph is often taken in tandem with a conventional image, allowing for a broader range of features to be seen.

In addition to its practical applications in a variety of scientific and professional fields, some artists, such as Italian photographer Elio Ciol, have employed infrared-sensitive film for purposes that are aesthetic rather than purely utilitarian. —DJS