Perceptions of Colours by Different Eyes

The historiography of early modern optics is dominated by a canon of names that stretches from Kepler and Descartes, via Huygens and Newton, to Euler, Young and Fresnel. As a result a long line of alternative approaches to light and vision have been relatively neglected. This goes in particular for numerous artists and connoisseurs that are not directly recognized as ‘scientists’. They did, however, do original optical research and developed ideas that tied in with artistic and manufactural practices more closely than the theories of light of the physico- mathematicians. On closer look, they appear to have shared a common approach to light and colour that does not fit the agenda of physical optics but was geared to esthetic and artisanal practices. This perceptual optics was of course as diverse as its students, but nevertheless seems to have constituted a line of theories of sight that concurred with the theories of light that dominates the history of early modern optics. In this paper I will discuss a few instances of perceptual optics, primarily Dutch cases of artists and connoisseurs that were concerned with the inquiry into light and colors. This runs from theories of art of someone like Samuel Hoogstraaten, the colour experiments of Lambert ten Kate, to the philosophy of a Frans Hemsterhuis. They provide a different early modern view on colours, that I will juxtapose with the physicomathematical eye of Newton et al.