Kodak High-Speed Infrared film, also known as Kodak HIE, was a popular
black-and-white infrared photographic film from
Kodak
The Eastman Kodak Company (referred to simply as Kodak ) is an American public company that produces various products related to its historic basis in analogue photography. The company is headquartered in Rochester, New York, and is incorpor ...
. The film was sensitive to the visible light spectrum (with decreased green sensitivity),
infrared radiation
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
up to 900nm in wavelength, and some
ultraviolet radiation
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...
as well.
The prominent blooming or "glow" often seen in the highlights of infrared photographs is an artifact of HIE and not of infrared light itself (nor even of all IR-sensitive films). This is because conventional photographic films have an
anti-halation layer that absorbs scattered light, while HIE lacks this backing. As a result, Kodak HIE (which also had a completely transparent base, whereas most films have slightly gray bases) had to be loaded and unloaded in total darkness. Light can enter the film through the tail protruding from a 35mm canister and without a gray base it will be piped into the film and expose it; without an anti-halation layer any light entering the substrate through the emulsion will be reflected back and forth inside the film, becoming diffuse as it travels and causing halation. Nonetheless, HIE was produced without a gray base and anti-halation layers so that sensitivity would be increased by allowing light to reflect back and forth, and because it was difficult to find any way of treating the film that would be effective at infrared wavelengths.
HIE featured a
polyester
Polyester is a category of polymers that contain the ester functional group in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include natural ...
film base
A film base is a transparent substrate which acts as a support medium for the photosensitive emulsion that lies atop it. Despite the numerous layers and coatings associated with the emulsion layer, the base generally accounts for the vast majorit ...
that was very stable but susceptible to scratches, and therefore required extra care during development, processing and scanning.
Discontinuation
As of November 2, 2007, "Kodak is preannouncing the discontinuance" of HIE Infrared 35 mm film stating the reasons that, "Demand for these products has been declining significantly in recent years, and it is no longer practical to continue to manufacture given the low volume, the age of the product formulations and the complexity of the processes involved."
[Kodak]
Discontinuance notice
/ref>[''"Due to declining demand, Kodak High-Speed Infrared Film / HIE has been discontinued, effective YE 2007."''; Kodak, ]
At the time of this notice, HIE Infrared 135-36 was available at a street price of around $12 a roll at US mail order outlets.
Despite the discontinuance of HIE, other newer infrared sensitive emulsions from Rollei and Ilford are still available, but have differing sensitivity and specifications from the long-established HIE.
References
High-Speed Infrared
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