Differences in lightness in achromatic transparency

It is presently unresolved whether lightnesses or differences in lightness are appropriate independent variables for models of perceived achromatic transparency. This experiment shows that differences in lightness rather than lightnesses affected the rated transparency and that local changes in differences in lightness altered the rated transparency locally. These results indicate that models of the perceived degree of transparency should be separately formulated for the different parts of a transparent surface and for the whole transparent surface. Two new models of the combined effects of lightness differences on the perceived transparency are proposed.