AshigrainColour reversal · Experimental
Kodak Aerochrome III 1443
Military infrared that turns green foliage pink.
False-colour infrared: foliage turns magenta-red. Original vs Ashigrain.
At a glance
- Exposure index
- 40
- Daylight
- Introduced
- 2001
- Discontinued
- Process
- AR-5
- Prints on
- Reversal, viewed directly
About the film
Colour infrared film began as a Second World War reconnaissance tool, designed to expose camouflage and decoys painted to imitate foliage.
Healthy leaves reflect infrared strongly, so on colour infrared film they turn magenta or red while painted objects show purple or blue. Kodak dates Aerochrome III Infrared Film 1443 to February 2001, when it announced the film as an improved successor to Aerochrome II 2443, with sensitivity out to 900 nm, finer detail, lower contrast and a new C-41 processing option. Kodak sold it for forestry, crop and tree-disease surveys, water-pollution studies and archaeology, where geometric patterns in vegetation can betray buried walls and graves. Its most famous use came outside science: from 2010 the Irish artist Richard Mosse photographed armed groups in eastern Congo on Kodak Aerochrome, turning the landscape pink and uniforms purple in the series Aperture published as Infra in 2012. Mosse told Aperture magazine that because infrared light is invisible, he was in effect photographing blind. With the cinematographer Trevor Tweeten and the composer Ben Frost he then shot The Enclave on 16 mm Aerochrome, a six-screen installation that represented Ireland at the 2013 Venice Biennale and won the 2014 Deutsche Börse Photography Prize. Kodak has since discontinued the film.
Sources for this history
- KODAK AEROCHROME III Infrared Film 1443 (KODAK Publication No. AS-77, TI2562), Eastman Kodak Company
- Kodak's Aerial Imaging Division Introduces Two New Color Infrared Films, Eastman Kodak Company
- AEROCHROME III Infrared Film 1443, Eastman Kodak Company
- Key Applications for Infrared Aerial Camera Film, Eastman Kodak Company
- Specifications and Characteristics of KODAK Aerial Films, Eastman Kodak Company
- Richard Mosse, Louisiana Museum of Modern Art
- Richard Mosse: The Enclave, Nasher Museum of Art at Duke University
- Infra: Photographs by Richard Mosse, Aperture Foundation
- Photographer Richard Mosse to represent Ireland at Venice Biennale, The Guardian
- Deutsche Börse 2014: Richard Mosse wins photography prize, The Guardian
- Richard Mosse: The Enclave, National Gallery of Victoria
- Solo exhibitions by Richard Mosse and Valérie Belin, e-flux
- Infra, The Irish Times
Shot on Kodak Aerochrome III 1443
Infra
Armed groups in eastern Congo photographed on Kodak Aerochrome with a large-format camera, which turned the landscape pink.
The Enclave
Six-screen installation shot with Trevor Tweeten on 16 mm Kodak Aerochrome in eastern Congo, shown at the 2013 Venice Biennale.
The look
Kodak Aerochrome III 1443 is a false-colour infrared aerial film. Healthy foliage turns magenta to red, reds render green, greens blue, and blues fall towards black.
Estimated infrared on Aerochrome: red foliage, dark sky.
False colour on everyday scenes.
Best for
- Landscapes with trees and grass
- Surreal music-video and fashion looks
- Summer foliage in full sun
Among the films
Science & sources
A false-colour infrared reversal film, shown directly without a print stage. Video footage has no infrared, so the infrared record is estimated from colour; it is not recovered infrared.
Response curves and the evidence behind the model
Compare manufacturer data with the Ashigrain model on the same axes. This shows the calibration to source curves; comparison with photographed film is a separate question.
Characteristic response
RMS granularity
Density variation (σD) measured through a 48 µm aperture. Where the datasheet gives a single grain value, the response away from that point is an approximation.
| Channel | Density | Datasheet-based σD | Model σD |
|---|---|---|---|
| R | 0.3 | 0.012598 | 0.013105 |
| G | 0.3 | 0.012598 | 0.013132 |
| B | 0.3 | 0.012598 | 0.013076 |
| R | 0.6 | 0.017816 | 0.018533 |
| G | 0.6 | 0.017816 | 0.018572 |
| B | 0.6 | 0.017816 | 0.018492 |
| R | 1 | 0.023 | 0.023926 |
| G | 1 | 0.023 | 0.023976 |
| B | 1 | 0.023 | 0.023873 |
| R | 1.5 | 0.028169 | 0.029303 |
| G | 1.5 | 0.028169 | 0.029364 |
| B | 1.5 | 0.028169 | 0.029239 |
| R | 2 | 0.032527 | 0.033836 |
| G | 2 | 0.032527 | 0.033907 |
| B | 2 | 0.032527 | 0.033762 |
Model limits
These images show the film model in use. Spectral response, lighting and viewing conditions include approximations, while halation, bloom, grain size, weave and flicker are not fully measured for each film. A real film capture also depends on development and print timing.
- Aerochrome is a labelled surrogate. Video footage records no infrared, so the infrared record is estimated from colour; it is not recovered infrared. The estimate keeps greys grey and raises foliage.
- From 700 to 780 nm the scene reflectance is the larger of the colour-based extrapolation and the infrared estimate (owner decision). Beyond 830 nm, where the CIE daylight tables end, daylight is continued by a blackbody of the same colour temperature.
- The film's own sensitivity, including 780–900 nm, the Wratten No. 12 filter, the curves and the dyes are used as printed; Kodak marks the dye curves as preliminary data.
- Its exposure index of 40 is an aerial film speed, not a pictorial ISO speed.
- Under custom lights the fast rendering path follows the spectral calculation much less closely than for other films, because the infrared estimate depends on each pixel's colour; a wider, film-specific tolerance applies.
- The source prints one visual MTF curve, not separate red, green and blue curves. The model applies it to all three layers.
- The source gives only RMS granularity 23 × 10⁻³ at net density 1.0. The response away from that point is modeled.
- No minimum-density spectrum is printed, so the reversal base-density spectrum is approximated. Reversal push and pull have no published curves and use a generic model.
- Individual dye amounts, layer interactions and push/pull behaviour are approximated where the datasheet provides no calibration. Grain size is assumed; published RMS granularity does not specify dye-cloud size.
- Characteristic response outside the published exposure range is an extrapolation, not measured film data.
- Veiling projection flare is not measured in the available sources. Its modeled contribution lifts screen blacks; it is not a measured projection-contrast claim.
Film guide: assumptions and practical choices
Sources
- Process: KODAK AEROCHROME III Infrared Film 1443 (KODAK Publication No. AS-77, TI2562), AS-77 / TI2562, Minor Revision 11-05 (©2005), p. 1
- Exposure index: KODAK AEROCHROME III Infrared Film 1443 (KODAK Publication No. AS-77, TI2562), AS-77 / TI2562, Minor Revision 11-05 (©2005), p. 3
- Diffuse RMS granularity: KODAK AEROCHROME III Infrared Film 1443 (KODAK Publication No. AS-77, TI2562), AS-77 / TI2562, Minor Revision 11-05 (©2005), p. 4
- Characteristic curves: KODAK AEROCHROME III Infrared Film 1443 (KODAK Publication No. AS-77, TI2562), AS-77 / TI2562, Minor Revision 11-05 (©2005), p. 10