Luminance Requirements and Color Appearances of Colored Displays in Turbid Water. II. Illuminated Ambient Viewing Environments

摘要

Ten light-adapted observers viewed six narrow-band wavelength displays and a white display through two artificially turbid and illuminated water media. The two water samples were intended to simulate the ambient underwater environment of a near-shore ocean at 20 meters depth and an inshore harbor or bay at 5 meters depth when surface illumination was full sunlight, 10,000 ft-candles. The 'Ocean' simulation was composed of a low concentration of relatively large-sized suspensoids illuminated by 17 ft-candles of light spectrally restricted to the green region, 540 nm peak wavelength. The 'Harbor' simulation was composed of a high concentration of relatively small-sized particles in suspension and illuminated by 214 ft-candles of light spectrally restricted in the yellow region, 600 nm peak wavelength. Against these two backgrounds, observers viewed 2-digit, self-luminous displays which varied in size and color. Observers controlled display luminance to three magnitudes defining three levels of display legibility: 'Minimum', 'Clear' and 'Limit'. At each legibility criterion, observers described the color appearance of the display using a forced-choice, color-naming technique and a restricted set of color-name alternatives: blue, green, yellow, red and white.