Goodman, T M; Freiding, A*; Eloholma, M*; Ketomaki, J*; Halonen, L*; Walkey, H*; Alferdinck, J*; Varady, G*; Bodrogi, P* (2007) Mesopic visual efficiency I: Detection threshold measurements. Lighting Res. Technol., 39 (4). pp. 319-334.

Full text not available from this repository.

Abstract

Achromatic thresholds were 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 revealed 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 seems to be less significant at lower luminance levels but it is accentuated for peripheral observation. Results obtained with broadband stimuli showed that the contrast threshold, defined in terms of V(l), was 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(lambda) were in better agreement with the experimental results, particularly for the peripheral detection task.

Item Type:	Article
Keywords:	mesopic vision, contrast threshold, achromatic threshold, mesopic photometry, spectral sensitivity, spectral luminous efficiency, night-time driving, mesopic visual performance
Subjects:	Optical Radiation and Photonics Optical Radiation and Photonics > Materials and Appearance
Last Modified:	02 Feb 2018 13:15
URI:	https://eprintspublications.npl.co.uk/id/eprint/4060