Researches in colour vision [electronic resource] : and the trichromatic theory (1913)
Abney, William de Wiveleslie, Sir, 1843-1920, Parsons, John Herbert, Sir, 1868-1957, donor, Institute of Ophthalmology, University College, London. Library Services · London : Longmans, Green and Co. · leaf 195
EXTINCTION OF COLOUR AND LIGHT 175 Extinction dependent on the Least Diameter of the Aperture. In making extinctions of light, the observer must be struck with the fact that before it finally disappears the … Fig. 60. shape of the disc or object entirely disappears, and that an irregularly-shaped spot is formed before it vanishes. This phenomenon naturally leads to the query as to whether within limits the shape of the illuminated spot has any effect on the extinction. One of the earliest
Ophthalmology · Eye · Color vision · Color Perception
Internet Archive · UCL Library Services, University College London (UCL) · Public domain (published before 1931). Free to use for anything.