Object analysis of the Stilling tables.
The CIE space that is occupied by the Stilling tables was found to be similar to that occupied by the Ishihara plates [LAKOWSKI, 1965] with the notable exceptions of a single table that extends into the blue area and two others that extend further into the green (fig. 4). Spectrophotometric curves show that the inks used are similar to those in other PIC plates, i.e. they have reflectance curves with broad-band characteristics. All tables are of the vanishing type and there is an attempt to differentiate between protan and deutan defects. Colorimetrically, tables I, II, VII and VIII have figure and background colours aligned mainly along the deutan isochromatic lines and only table III is a clear protan plate. Tables V, VI, IX, X and XI are ambiguous in design, i.e. they would be confused by most colour-deficient persons. Of the tables designed to detect blue-yellow deficiencies (tables V, VI, XI and XII), only the colours in table XII are aligned along tetartan confusion lines, while the other three tables are indefinite in their design. Thus the usefulness of these plates for detecting acquired dyschromatopsias is limited.
D003119:Color Perception Tests / Q000379:methods*; D003201:Computers; D006801:Humans