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Proceedings Paper

Task performance and contrast polarity on hard copy and video displays
Author(s): James E. Sheedy; Ian L. Bailey; Darlene Fong; Mark Ostermeier; Stuart Stanton
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Paper Abstract

Performance was measured on an editing task which required counting the number of occurrences of an assigned letter in a paragraph of random letters. The task was presented in three different display modes: (a) a video display (VDT) with white characters on a black background, (b) a white-on-black photograph of the VDT display, and (c) a black-on--white photograph of the VDT task display. The viewing conditions for the three display modes were matched. Defocus was introduced by cylindrical lenses (simulated astigmatism) and by plus lenses. Performance was measured by time and accuracy in completing the counting task. There were 19 normally-sighted young adult subjects tested with the task in the three display modes under 6 levels of defocus. For the hard copy displays, performance was significantly faster (on average by 6.6%) for black characters on a white background. Performance with the black background photographs was consistently, but marginally (0.9%), faster than with the VDT displays. Cylindrical defocus of 1.50 diopters substantially impaired efficiency, but low-power plus lenses did not affect performance.

Paper Details

Date Published: 1 October 1990
PDF: 9 pages
Proc. SPIE 1249, Human Vision and Electronic Imaging: Models, Methods, and Applications, (1 October 1990); doi: 10.1117/12.19660
Show Author Affiliations
James E. Sheedy, Univ. of California/Berkeley (United States)
Ian L. Bailey, Univ. of California/Berkeley (United States)
Darlene Fong, Univ. of California/Berkeley (United States)
Mark Ostermeier, Univ. of California/Berkeley (United States)
Stuart Stanton, Univ. of California/Berkeley (United States)

Published in SPIE Proceedings Vol. 1249:
Human Vision and Electronic Imaging: Models, Methods, and Applications
Bernice E. Rogowitz; Jan P. Allebach, Editor(s)

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