Kodak Aerochrome

Aerochrome started as a military tool. The US Army needed aerial film that could distinguish living vegetation from painted camouflage nets, because chlorophyll reflects infrared light strongly and paint does not. The result was a three-layer reversal film where the red-sensitive layer was replaced with an infrared-sensitive layer, shifted so that green foliage rendered magenta or pink and blue sky went deep cyan. It worked. Reconnaissance pilots could spot concealed positions that looked identical on panchromatic film.

Kodak kept making it through the Cold War and eventually released 35mm and 120 versions for commercial and artistic use. You needed a yellow or orange filter to block UV and blue light; without one the images went muddy. An orange filter gave the classic magenta trees. A deep red filter pushed foliage toward yellow-white. The results were completely unlike any other film on the market.

Dean Bennici bought the last bulk emulsion sheets from Kodak in 2008 and spent the next decade hand-cutting and respooling it as the sole distributor, supplying Richard Mosse for his Infra series. His Infra series, shot in eastern Congo between 2010 and 2012, used the infrared false color to photograph armed groups in a landscape that looked alien and beautiful simultaneously. The work won the Deutsche Borse Photography Prize in 2014. It is probably the most significant artistic use the film ever saw, and it happened right at the end.

Shoot it in daylight only. The infrared sensitivity drops sharply at low light levels, and the three-layer balance falls apart in artificial light entirely. Process in standard E-6. The reciprocity exponent is 1.10, and Zone Light Meter applies that correction past one second, though in practice you will almost never expose Aerochrome past a second if you are using it as intended. The film is long gone from production, and the remaining stock floating through eBay and estate sales is twenty-plus years old. Expect color shifts. That is part of it now.