Mesopic visual efficiency I: detection threshold measurements

Achromatic thresholds are measured at three sites to investigate the effects of light spectrum on achromatic detection thresholds in the mesopic region. The results of measurements using quasi-monochromatic targets reveal spectral sensitivity functions with two or three peaks, a so-called `chromatic effect' which is assumed to be due to the influence of the colour-opponent channels. This chromatic contribution seem to be less significant at lower luminances but it is accentuated for peripheral observation. Results obtained with broadband stimuli show that the contrast threshold, defined in terms of V(), is markedly higher for red targets than for other colours, particularly at lower light levels. For these broadband targets, contrast threshold values calculated using the new spectral sensitivity curves instead of V() are in better agreement with the experimental results, particularly for the peripheral detection task.(A)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/14771535
• Authors:
  • FREIDING, A
  • ELOHOLMA, M
  • KETOMAEKI, J
  • HALONEN, L
  • GOODMAN, T
• Publication Date: 2007

Language

• English

Media Info

• Pagination: 319-334
• Serial:
  • Lighting Research and Technology
  • Volume: 39
  • Issue Number: 4
  • Publisher: Sage Publications Limited
  • ISSN: 1477-1535
  • Serial URL: http://lrt.sagepub.com/

Subject/Index Terms

• TRT Terms: Color; Evaluation; Luminance; Measurement; Vision
• Uncontrolled Terms: Light color
• ITRD Terms: 6784: Colour; 9020: Evaluation (assessment); 9036: Light (colour); 525: Luminance; 6136: Measurement; 2066: Vision
• Subject Areas: Safety and Human Factors; I83: Accidents and the Human Factor;

Filing Info

• Accession Number: 01087077
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Jan 29 2008 9:34AM