Colour vision, a discussion of the leading phenomena and their physical laws (1922)
Peddie, William · London, Arnold · leaf 60
re i is the intensityof the light, and di represents the minimum increase whichcan just be perceived. Visual discrimination is thereforeweak when the ordinates are great, and conversely. In orderthat a great range of intensities shall be represented, equallyspaced abscissae represent the logarithms… … 10000 Fig. 1.—Change of Sensation with Intensity of Illumination. If di/i is constant, Fechners law is obeyed. The closenesswith which it is followed throughout a great range of intensities,for all wavelengths, is exhibited in the region / of the diagram ;and the great deviations from it, in the…
Color
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
