Filters which remove the visual spectral components (minus visual) produce optical density increases in all three layers of Kodak Aerochrome infrared film, type 2443. The increased density was reflected in a shift of the characteristics curves of the film; the amount of shift was dependent upon the filtration used. In this study, color compensating filters (CC filtes) in the CC20 range were used. Two types of density increases were observed. The first resulted in the attenuation of reflected energy in certain spectral regions caused by the filters used and the amount of attenuation was measured as a density increase relative to a standard exposure of the same subject; the standard being Type 2443 exposed through a Wratten 12 (W12) filter. The second type of density increase, called an attenuation factor, was detected and resulted from attenuation of the other dye layers present in the film. The attenuation factor was independent of the photographic CC filter factor. Statistical analysis of density values measured on operational test film showed that the density increases were measurable and normally large enough to cause the characteristics curves to shift in the direction of increased density (i.e., towards the red characteristic curve). The distributions represented by the blue, green, and red characteristic curves shifted to the right with the blue and green distributions shifting by an amount that would place them within the red distribution if a larger value minus auxiliary filter were used.

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  • Corporate Authors:

    American Society of Photogrammetry

    105 North Virginia Avenue
    Falls Church, VA  United States  22046
  • Authors:
    • Worsfold, R D
  • Publication Date: 1976-11

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 1385-98
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00148685
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 30 1977 12:00AM