INFRARED FILM SPECTRAL SENSITIVITY
General notes
The diagram below is for illustrative purposes only and is based solely on manufacturer's published data.
- Kodak HIE is unique in being sensitive to over 900nm and is capable of producing IR effects with minimal filtration
- Although both Ekfe IR820 and Rollei IR400 are sensitive to 820nm, the Efke film is more responsive to the infrared wavelength because its gradient within the 750m - 820nm wavelengths is less steep than the Rollei film.
- SFX is not sensitive to infrared light and has a peak red sensitivity at 720nm, and extended red sensitivity up to 740nm. Nonetheless, this film is capable of producing nice IR-type effects with an IR filter
- The log sensitivity is a reflection of film speed and the position of each film on this axis is primarily indicative of film speed and is not an indicator of IR sensitivity.
- Grain, contrast and tonality are not represented in this chart
Conclusion
All four of the films illustrated here are capable of producing IR-type effects, and each one has its own strengths and weaknesses. Kodak HIE is clearly much more sensitive to the infrared end of the spectrum than any other film; however both HIE and Efke IR820 tend to produce strong IR effects at the expense of considerable grain. Rollei IR400 and Ilford SFX200 are much finer grained films, but have a less pronounced Wood effect. We recommend conducting your own tests to find out which film is best suited to your requirements.
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