Kodak High-Speed Infrared
|Kodak High-Speed Infrared film|
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 although conventional photographic films have an anti-halation layer that absorbs scattered light, HIE lacks this backing.
Kodak HIE must only be loaded and unloaded in total darkness.[footnotes 1]
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." At the time of this notice, HIE Infrared 135-36 was available at a street price of around $12.00 a roll at US mail order outlets.
Despite the discontinuance of HIE, other newer infrared sensitive emulsions from EFKE, ROLLEI, and ILFORD are still available, but have differing sensitivity and specifications from the long-established HIE With the discontinuance of HIE, Efke's IR820 film has become the only IR film on the market with good sensitivity beyond 750 nm.
- This is because HIE lacks anti-halation layers and has a completely transparent base rather than being directly due to infrared sensitivity. Film usually has a slightly fogged base and anti-halation layers coated on it in order to stop light bouncing around in the substrate once the image has been taken. Light can enter film through the tail protruding from a 35mm canister and without a fogged 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. HIE lacked a fogged base and anti-halation layers for two reasons: sensitivity is increased by allowing light to reflect back and forth and it was difficult to find any way of treating the film that would be effective at infrared wavelengths.
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