Seurat’s new idea

“Painting with light”:

The main purpose of this Post is to explain what I mean by “Seurat’s new idea”. Most people would probably leap to the conclusion that I am referring to the “Pointillist method” that he developed, and for which he is justly renowned. But the method was never the main idea, which was to “paint with light” (as opposed to merely “painting light”). No previous artist had attempted to do this.

At least since the Italian Renaissance, the artistic community had been particularly interested in depicting effects of natural or artificial light on the appearance of objects and scenes.  They made impressive progress by conceiving matters in terms of  whole-field lightness relations (chiaroscuro). Seurat’s new idea opened up the unexplored possibility of introducing the dimension of colour into the mix. In doing so, whether directly or indirectly, he was responsible for opening the way for the possibility of adding a new dimension to the experience provided by representations of the effects of light in paintings.

In itself, this step could justifiably be described as a “quantum leap”, but as it turned out the influence of Seurat’s new idea was to have other far reaching implications. In time it would also lay the foundations  for enhancing, not only effects of “illusory pictorial space” but also the sense of both “surface” and “surfacelessness” in paintings.

But even this was not all, for another side-effect of Seurat’s new idea was its contribution to the explosion of colourfulness in paintings.  This had been kick started by the discovery by scientists that colour is not a property of surfaces in the external world, but a creation of  eye/brain systems. In the wake of this mind blowing reality, earlier Modernist artists were already using brighter colours and juxtaposing complementary pairs, but two requirements of the Pointillist method pushed matters significantly further. These were:

  • The systematic use of  juxtaposed complementary colour pairs, within the optically mixed arrays of tiny dots that characterise Pointillism.
  • The need to conceive of colour mixing in terms of a colour circle with many more segments than the six segment one (consisting of three primaries and their three complementaries) favoured by the Impressionists. Seurat’s idea meant that he had to represent as many parts of the visible spectrum as possible. To do this he needed to make use of the widest range of the most fully saturated pigment colours available.

Between them these innovations had the effect of hugely increasing the range and subtlety of both colours and colour combinations  to be found in paintings produced after 1886, the year that Seurat first exhibited “La Grande Jatte”, his game-changing painting.

For more details click on the link below to Chapter 8 of my book “Painting with Light and Colour”. For those who have not read the previous four chapters, the next section provides a short resume of them (links to the chapters themselves can be found at the bottom of this page).

Short resume of previous chapters

  • Chapter 4 : Describes the Renaissance approach to painting light, which centred on local and whole-field lightness relations with particular reference to finding the darkest and lightest regions in the scene (chiaroscuro) and gradations of lightness across surfaces. In this scheme of things the depiction of shadows was a matter of painting “what you see”, which seemed reasonable enough, but brought with it all sorts of unsuspected problems.
  • Chapter 5 : Focuses on the scientific revolution in the understanding of light and colour that had its origins in the work of Isaac Newton and the insights of the numerous scientists who realised that all sensory experiences including those that relate to colour and effects of light are made in the head. Newton clarified the physical nature of light. The perceptual scientists introduced concepts like the“three primaries”, “induced colour”, “complementary colours” and “colour/lightness contrast effects”.
  • Chapter 6 : Shows that the Impressionists had an agenda which included the idea of emphasising the reality of the picture surface and playing off the ephemeral and the permanent aspects of appearance.
  • Chapter 7 : Uses photographs to elucidate the meaning of the words “opaque”, “translucent”, “glossy” and “matt”. Particular attention is given to effects on appearances of interreflections and viewing angles.

The diagrammatic origin of Seurat’s new idea

As it does not appear in Chapter 8, but earlier in the book, I am including in this Post the diagram from a physics book that kick started Seurat’s new idea. It was from this that he learnt that  the white daylight light that strikes a surface interacts with it in one of two ways:

  • One part enters the surface and is scattered around inside, before being scattered back out again. While inside, some wavelengths are absorbed. The remainder are scattered-back-out again to produce the limited wavelength combinations that give us “body colour”.
  • The remainder never enters the surface, but is reflected back directly from it (as from a mirror), such that it leaves it without changing its wavelength composition to produce “reflected light”.

The component that interested Seurat is the “reflected light”. By combining his understanding of this with the discoveries of perceptual scientists mentioned above, Seurat believed that he could represent it in paintings by means of mosaics of tiny dots containing juxtapositions of complementary, or near-complementary, pairs.




The inspirational diagram

Seurat's new idea
The diagram that seeded Seurat’s new idea. It is the reflected back “white” light that informs the eye/brain about surface-solidity, surface-form, in front/behind relations and ambient illumination.


Posts relating to other chapters from “Painting with Light and Colour”:

Another Post that relate to painting reflected light:

List of all Posts so far

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7 thoughts on “Seurat’s new idea”

  1. magnifique. Revenir sans fin sur les connaissances des “mystères” de la couleur m’aide pour suivre mon chemin de créativité. Merci Francis

  2. The intersection of art and the sciences is truly thrilling to uncover here, thank you for your writing!

    1. Hello Sawyer, So good to hear from you and thanks for your positive comment. When I saw the diagram that inspired Seurat and realised how it related to his idea of “painting with light” as opposed to just “painting light” (which was an aim of mosts artists since the Italian Renaissance), it changed my life. It did so by setting me on the way to the cooperations with scientist colleagues at the University of Stirling that enabled me (a) to explain “colour constancy” , (b) to discover (as far as I know for the first time) visual systems that that tell us about surface solidity, surface form, in front/behind relations and ambient illumination, and (c) to find a reliable method of using colour to enhance the sense of illusory pictorial space.

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