Introduction to the drawing book

After posting thirty-seven of the chapters of my four books, I realise that I have missed out the “Introduction” to “Drawing on Both Sides of the Brain”. In the edited extract from it below, some general remarks are followed by a brief focus on two issues of fundamental relevance to what follows. Also, as an extra bonus, I have added three images .

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EDITED EXTRACT

introduction
A drawing by Auguste Rodin, one of two artists who set me on the way to scientific research

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GENERAL INTRODUCTION.

This volume differs in fundamental respects from earlier books on the same subjects. It offers new and practical guidance on drawing-from-observation. It does so whether the artist is seeking:

  • Greater accuracy.
  • More expressive power.
  • Ways of speeding up without losing control.

Its starting point is an analysis of widely used artistic practices and teaching methods. The next step is to explain not only why these have both proved to be of lasting value but also why, as they are currently taught, they have significant limitations.

A main source of evidence for the proposals elaborated in the following pages is research, done by myself and colleagues at the University of Stirling in Scotland, into how artists use their eyes when drawing or painting. This forced me to a number of conclusions that differ fundamentally from those provided by other authors, including those promoted by Betty Edwards in her extremely popular  book, “Drawing on the Right Side of the Brain”.

A similarity between Betty Edwards and myself is that both of us link our main explanations to contemporary science, with a special focus on neurophysiology. The difference is that the conclusions to which we come are radically different. While she relies heavily on a false theory of brain function, my arguments are are wider ranging, more up to date and demonstrably more relevant to drawing practice. As a result, I am able to offer a great deal of  new and reassuring information on human visual capacities, clarify the nature of the obstacles facing all who engage in drawing from observation and indicate effective ways of circumventing them.

During my 30 years teaching at the Painting School of Montmiral, I have had the opportunity of testing the research-based ideas on hundreds of students of all levels of attainment and a wide variety of aspirations. Although the outcome is clear and encouraging, a word of warning is appropriate. Both experience and theory make it clear that, while early progress will almost always be rapid, both for beginners and experienced artists, there is no escaping the fact that, as with all skills, the highest levels of attainment require a longer term commitment.

Experience and theory also show why early difficulties seem more daunting to some people than for others. Should this turn out to be your case, there is no need to be discouraged. No matter what your starting level, you can have confidence that, if you have the motivation to persevere, the new ways of looking and doing that I advocate will help you to far exceed your expectations.

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THE SCIENTIFIC PERSPECTIVE

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introduction
A drawing by Edgar Degas, the other of the two artist who set me on the way to scientific research.

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My experience as a teacher makes clear that everyone has difficulties with the accurate depiction of the outlines of objects. My research at the University of Stirling helps us understand why. It also sets us on the way to achieving the combination of accuracy, speed and expressive power mentioned above.le of

As the  science upon which much of my teaching depends will be unfamiliar to readers, a few words on two key ideas are appropriate. These centre on the subjects of “the variability of appearances” and “recognition”.

Variability

A useful preparation for understanding the nature of  the problem with which variability confronts us, is the realisation that no two objects or parts of objects ever present the eyes with the same outline, even ones that are classified as the same object-type. Indeed, because appearances are altered by every change in viewing angle and/or viewing distance, even the same object (unless it is a sphere) will never be identical in shape unless viewed from exactly the same position. Each set of relationships, whether between different sections of contour or regions colour will always be unique.

This fundamental truth of visual perception brings us to an extremely important implication of this unvarying rule of variability and the consequent uniqueness of all perceived objects. It is that, since, by definition, recognition depends on seeing something as being the same on different occasions, the precise characteristics of the contours artists seek to represent can only have a supplementary role in the processes that enable it.  Accordingly recognition must regularly involve overlooking the details of shape in favour of more general information. As we shall see in the following pages, the extent of overlooking can be huge.

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Figure 1: A diagram of the working principles of the analytic looking cycle
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Recognition

Most people feel that they experience “recognition” as a conscious activity. But they are wrong to do so. As illustrated in Figure 1 (the details of which will be explained in due course), this key process in sensory perception always takes place before conscious awareness is achieved. The reason is that the function of recognition is not to produce an image of an object, but rather to access the knowledge required for activating instructions as to how to react to it.
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As the diagram illustrates, the the knowledge accessed is always in the form of action instructions. These may be concerned with guiding arm, leg or other body movement or they may direct the movements of eye, head or body that enable us to target aspects of appearances that require special attention. It is only at this analytic-looking stage that consciousness has a role in visual perception.
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But how does the eye/brain know where to target attention? It may help when seeking an answer to this question to remember that analytic-looking skills, like all other skills, are developed for specific purposes. Some skills, such as the ones learnt when very young, create platforms for more advanced ones. Anybody who sets themselves to learn a totally new skill has no option but to start with existing skills. All of these will be a compound of basic skills learnt as an infant, such as those required for grasping objects or for guiding the direction of crawling, and more advanced ones that have been developed later, such as those required for washing up, for using a computer or for any kind of sport.
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This being the case, it follows that, if we wish to acquire complex visually mediated skills, we will have to learn the action instructions necessary for guiding appropriate ways of looking. Accordingly, although people learning to draw for the first time might have had experiences relating to other tasks that have allowed them to develop skills that could contribute the acquisition of drawing skills, they will never be enough. No matter how near the fit, they can only be of limited use unless appropriate ways of building upon them are developed.
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If advanced artists assume that all this has no relevance to them, they should think again. The handicap of being saddled with old knowledge when facing new situations does not only apply to learning skills in hitherto untried domains of activity. It also applies to developing any skill at all beyond its present stage, no matter how well honed that may be. When Edgar Degas, one of the most skilled drawers in history, asserted, “I must impress on myself that I know nothing at all, for it is the only way to make progress”, he was making the claim that, no matter what the subject matter, fresh ways of looking will always be required.  In view of the unvarying variability of appearances, there is no alternative but to agree with him.
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A more familiar and general way of expressing the above conclusions is that learning a new visually mediated task requires leaving aside bad, old habits in favour of adopting good, new ones. This book provides comprehensive information concerning how this can be done in the domain of drawing from observation
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Introduction
My son Thomas at a difficult moment in his life, a drawing that owed a great deal to my scientific research
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An artist among scientists

Mutual benefits

During the twelve years I worked among scientists at the University of Stirling in Scotland, a transformation took place in my understanding of just about everything to do with the role of the eye and the brain in the organisation of the  the main perceptual and motor skills used in the making of drawings and paintings. PART 2 of my book “What Scientists can Learn from Artists” tells of experiments done by myself, colleagues and other scientists that made especially significant contributions to this exciting development.

Chapter 7, (accessed by clicking on link below) offers an autobiographical introduction the contents of PART 2 that gives a flavour of what I was up to in those years. A theme that runs through its pages is that the transformative learning was a two way process, offering benefits to all concerned. Time revealed many unexpected advantages in my being a combination of an experienced artist/teacher and a naive beginner in all the scientific disciplines in which I was to participate. My new colleagues found themselves faced with a drip feed of questions coming from unfamiliar perspectives that were to prove their value as catalysts capable of stimulating new ideas for a surprising number of highly expert scientists, working in a variety of disciplines. In return, their often participatory responses enabled me to put together the body of ideas that underpin the originality of my books, my teaching and, to an important extent, my work as an artist.

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CHAPTER 7-AN ARTIST AMONG SCIENTISTS

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artist aong scientists
Two stripy paintings, made while the story above was unfolding.

 

Chapters from “What Scientists can Learn from Artists”

These deal in greater depth with subjects that feature in the other volumes

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More information on my main colleagues

 

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Illusory pictorial space

Illusion in painting

Over the centuries, at least since the Italian Renaissance, artists have sought to represent three dimensional objects and scenes on two dimensional surfaces. By implication, this required them to create an eye-deceiving third dimension (‘trompe-l’œil).

To achieve their objective, they and their successors:  (a) mastered the laws of ‘linear perspective’, (b) delved deeply into the subject of ‘anatomy’, (c) explored the form-making properties of ‘gradation’, (d) recognised the importance of ‘overlap’,  (e) provided explanations for the phenomenon of ‘aerial perspective’, (f) explored whole-field lightness relations (‘chiaroscuro’) and (g) demonstrated the value of existing knowledge of the form of objects and the layout of scenes in influencing how viewers would perceive them (‘cognitive  cues‘).  In other words, over the centuries the artists have pioneered our understanding of just about everything that psychologists of perception needs to know about illusory pictorial space.

However, there was one big absence and it is this that dominates the discussion of illusory pictorial space in two of my books. In “Painting with Light and Colour” the subject is approached from the perspective of artistic practice. In “What Scientists can Learn from Artists”, which contains the chapter that can be obtained by clicking on the link below, its treatment has both scientists and artists in mind.

The chapter also touches briefly on the issue of what they saw as the immorality of deceiving the eye, which was to have both a decisive and long lasting effect on the evolution of painting from the Impressionists until the late 1960s at least. More on this in my other books.

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CHAPTER 6-ILLUSORY PICTORIAL SPACE

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A pictorial history of illusory pictorial space

 

 pictorial depth cues illustrated
Vittore Carpaccio (565-1625) – Lots of depth cues: overlap, shading, linear perspective, etc.

 

 pictorial depth cues illustrated
Claude Loraine (1600-1682) – Using aerial perspective to deceive the eye

 

 pictorial depth cues illustrated
Berth Morisot (1841-1895) – Brush marks made evident to emphasise the picture surface

 

 pictorial depth cues illustrated
Cézanne (1839 – 1906) – Doing his best to hold everything on the picture surface

 

 pictorial depth cues illustrated
Picasso (1882-1973) – Intent on keeping depicted surfaces near the actual picture space

 

 pictorial depth cues illustrated
Peit Mondrian (1872 1944) – Sought to depict a “spiritual space” within the flat picture surface.

 

illusory
Jackson Pollock – The critic Clement Greenberg, described him as creating as “A space within the picture surface”

 

illusory
Ellsworth Kelly (1953-2015) – Failing to eliminate illusory pictorial space

 

illusory
Michael Kidner (1917 – 2009) – Gave priority to keeping colours flat on the picture surface

 

illusory pictorial space illiminated
Ellsworth Kelly (1953-2015): Unambiguous flatness at last. But is it a painting or a sculpture?

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Other Chapters from “What Scientists can Learn from Artists”

These deal in greater depth with subjects that feature in the other volumes

 

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Why read my science book?

A paradigm shift

Back in November 2019 I started posting chapters from “What Scientists can Learn from Artists”, the book which presents the research and the science based ideas that that lie behind much of the contents of my three other books: “Drawing on Both Sides of the Brain”, “Painting with Light and Colour” and ” Fresh Perspectives on Creativity”. I set the ball rolling with with six of the chapters that describe research findings which were in large part responsible for:

  • Overturning almost all the preconceptions I had about the nature of visual perception.
  • Providing the building blocks required for replacing them with the coherent picture presented in these books.

When I first came across the material I have summarised in these chapters, their cumulative effect on me was more than just fascinating. It amounted to a paradigm shift. My hope is that reading them will perform the same service for others, particularly when buttressed by the contents of earlier and later chapters.

Below is an extract from the “Preface” to “What Scientists can Learn from Artists”, which summarises its structure. The chapters so far published in my Posts come from PART 2. In the next weeks I will be posting chapters from PART 1 and in the coming months chapters from PART 3.  I will wait to see the level of interest before I go on to PART 4, which I have reason to believe will be is considerably more demanding on non scientists.

Also below are links to already published Posts.

The structure of the book

Because the context of the knowledge of scientists and artists is so different, it seems prudent to provide a certain amount of background material which, while likely to be familiar to readers from one side of the arts/science divide, may well not be to those from the other. Thus PART 1 contains a number of general ideas both artistic and scientific many of which may well be familiar to one community and not the other, and PART 3 provides a basic introduction for non scientists to the nature of visual perception that emphasises the variety of visual systems involved in different aspects of visual processing. The function of PART 2 is to describe the main experiments used to underpin the theoretical speculations which lead to the general model of perceptual and cognitive processes that provides the subject matter for PART 4. Throughout the attempt has been made to present ideas in such a way that they will be understood by both groups.

Chapters from my book “What Scientists can Learn from Artists”

These deal with subjects that feature in the other volumes in greater depth.

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A reminder

There are still places vacant for the 2020 sessions of the Painting School of Montmiral. Here a three photos to remind you of our idyllic setting and the seriousness of the teaching

book chapters
Castelnau de Montmiral from the South

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book chapters
View from the breakfast balcony

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book chapters
Out on the esplanade

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Me discussing student work

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Constraint in artistic aids and practices

Is constraint necessary for creativity?

The purpose this Post is to provide a link to “Constraint in artistic aids and practices , Chapter 9 in my book “What Scientists can Learn from Artists”. As in several other Posts that publish book chapters, I include a slightly edited reprise of its“introductory”, in the hope it will whet your appetite and encourage you to click on the link below. I am hoping that when you have read all the chapters of all my books, you will realise that the answer to the question posed in the heading to this section is “Yes”. The images below illustrate two methods of constraint favoured by artists in former centuries that foreshadow ones that are widely used today: For example, photographs, slide projections, and computer controlled images. All of these, whether consciously or not, make use of constraints, the possibilities of which have been developed by evolution over the millennia, such as standing still, choosing a viewing distance or closing an eye al of which constrain input to our visual systems and, thereby, enable learning and creativity, its corollary.

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constraint
figure 1 : Illustrates the lengths of which artists were prepared to go to achieve accuracy

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constraint
Figure 2 : Illustrates a “camera obscura”, a simpler solution to the problem of obtaining accuracy than the one illustrated in Figure 1. However, both imply artist’s mistrust of unaided analytic looking

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Introductory

If we want to be creative, we will have to free ourselves from the constraints of old ways of doing things in order to go beyond them into new territory.

In this chapter, we take a step towards the goal of a practical understanding of how this might be done. It starts with my telling how I stumbled on the intuition that constraint may be a necessary condition for exploring the unknown, and provides examples of how the community of artists, whether consciously or not, have made much use of this possibility. Eventually I found myself coming to the seemingly paradoxical conclusion that constraint is necessary if we are to achieve either meaningful freedom or creative self expression. I also came to realise that the use of constraint is one of the guiding principles of our evolution as a species.

My approach to going deeper into the creative powers of constraint, starts with account of how I came to realise their central importance. I use the particularities of my own story because of the insights it furnishes relating to the creative process in general: long periods of gathering data, struggles with the confusion that they seem to engender, a sudden intuition that provides a lead on how order might be found and, finally, doing the work necessary to test its validity.

The inspiration for my breakthrough came when reading a book by J.J. Gibson, one of the most controversial yet influential perceptual psychologists of the day.

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CHAPTER 9-CONSTRAINT IN ARTISTIC PRACTICES

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Other chapters from “What Scientists can Learn from Artists”

These deal in greater depth with subjects that feature in the other volumes

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Movement created information

The title of  the chapter to which this Post is linked is,“Information created by movement”. It comes from my book, “What Scientists can Learn from Artists”, which is divided into four Parts.

  • The “First Part”  introduces ideas (a) to artists, who are not familiar with the science, and (b) to scientists, who lack a background in art.
  • The Second Part is called “The Evidence”.  It includes chapters on (a) traditional artistic practices (b) my “drawing experiments“, (c) the importance of “movement” to visual perception (this Post), (d) “colour” related phenomena (all but one already posted) and (e) other aspects of vision with profound consequences (already posted).
  • The “Third Part” presents images of neural processes and lists relating to regions of the brain that participate in visual perception. Even though these are hugely simplified and very far from complete, they suggest that something amazing and seemingly unimaginable must be going on in our eyes and our brains.
  • The “Fourth and final Part” goes deep into theory with a view to gathering the disparate strands presented in the preceding chapters into a coherent whole

As indicated above, the link provided in this Post gives access to a chapter that focuses on the role of  “movement” in visual perception.  As in other Posts, I include below a slightly edited version of the “Introduction”, in the hope that it will encourage you to click on the link situated below it, which gives access to the chapter as a whole.

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movement
Read the chapter to which this Post is linked to find how a few milliseconds of  movement can catapult these points of light into two outlined figures at play.

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Introduction to Chapter 11

The studies of blind-sight and unilateral neglect discussed in the last chapter show that visual perception is not the kind of thing that can be understood by introspection alone. Rather, it is the fruit of a labyrinthine concatenation of neural processes, involving activity in large variety of locations within the brain. The same message can be derived from the diagrams to be shown later (in chapters 14 and 15). These provide glimpses of a massively complex system containing a wide variety of neural structures, hundreds of millions of neurons and untold billions of connections between them. This chapter is grist to the same mill. It concentrates on the work of James Gibson, Nicholas Bernstein and Gunnar Johansson, three scientists who extended our understanding of the experience of seeing.

Although many might suppose that movement-generated perceptual cues could have little or nothing to do with drawing static objects from observation, they would be wrong, as made clear in my book on drawing. However, their usefulness in drawing practice is far from the only reason for devoting a whole chapter to them. Thus: Gibson created a new interest in the power of movement-generated cues, Bernstein used elegant mathematics to demonstrate the interdependence of top-down and bottom up influences in the control of visually guided movement, and Johansson produced a demonstration that blew away a multitude of misconceptions.

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CHAPTER 11- GIBSON-JOHANNSON – INFORMATION CREATED BY MOVEMENT

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Other chapters from “What Scientists can Learn from Artists”

These deal in greater depth with subjects that feature in the other volumes

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Blindsight & the bakery facade

This Post provides a link to Chapter 9 of “What Scientists can Learn from Artists”, the book that presents the science that supports so many of the ideas and proposals found in my other three books. Its full title is “Blindsight, unilateral neglect and the bakery facade illusion”. It recounts what for me was a particularly exciting adventure into the mysteries of eye/brain function. This had its origins in research I was doing at the University of Stirling, Scotland, and reached its conclusion here in Montmiral, as a result of trying to understand why a student, who was good at drawing accurately, persisted in seeing the slope of a wall top differently from three other people sitting close to him. It turned out to be a question of his being taller than them and, as a result, he was relating the wall top to a slightly different background, with fascinating consequences: Ones which were to provide the substance not only of the chapter to which this Post is linked, but also of a closely related chapter in my book on drawing.*

Blindsight
Piazza del Duomo, Milan, which plays an important role in a fascinating, game changing story told in this chapter.

Two paradoxes

The bringing together information about “blindsight”, “unilateral neglect” and “The bakery facade illusion” provides yet another approach to making  clear that the process of “seeing” is complex. It also presents evidence that lead to two paradoxes, namely that:

  • we can all “see” what we cannot see
  • we can all “imagine” what we cannot imagine”.

Luckily knowledge of eye/brain systems can make sense of these seemingly senseless propositions. Also, it can alert artists to some deep seated problems they cannot avoid facing when drawing or painting from observation.

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As I usually do when presenting book chapters, I am providing below an edited version of the “Introductory” to the chapter in question in the hope that it will whet your appetite for reading the chapter itself.

Introductory

This chapter delves a little deeper into the subject of visual mechanisms and systems. It is one of the most important in the book because it provides information concerning the central problem as to how preconscious, bottom-up processes enable top-down control of the skilled use of eye/hand coordination. The first part takes the form of a detective story. The key to unlocking the mystery lies hidden in two experiments, relating to two visual impairment syndromes, each resulting from damage to a different part of the brain. Though other syndromes can be legitimately given the same names, they will be referred to as “blindsight” and “unilateral-neglect”. The second part of the chapter describes a powerful visual illusion, first noticed in relation to the facade of a building in Castelnau de Montmiral, S.W. France. This is shown to have general implications both for artists trying to depict scenes containing rectangular surfaces and for psychologists of perception, trying to understand the mechanisms underlying analytic-looking.

 

WHAT SCIENTISTS CAN LEARN FROM ARTISTS” CHAPTER 10 – “Blindsight, unilateral neglect and the bakery facade illusion”

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*  “Axes of symmetry, recession and the constancies”: A chapter from my book on drawing that shows some of the ways the theory in this more scientific chapter can be related to practice.

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Other chapters from “What Scientists can Learn from Artists”

Like the chapter to which this Post is linked, the links below can be used to access chapters from the middle section of my  book that elaborates on the science behind subjects that feature in the other volumes:

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The other constancies

My two previous  the Posts provided links to Chapter 12, “Local colour interactions” and Chapter 13, “Colour constancy”, from my book “What Scientists can Learn from Artists”. This Post provides a link to Chapter 15, “The other constancies”. Below the two images you will find an edited version of the “Introduction” to this chapter. As with other Posts, if you find that the subject matter interest you, you can click on the link below to the .PDF version of the chapter as a whole. The images illustrate two of the visual perceptual problems with which artists have had to come to terms.

constancies
Cézanne read Helmholtz and took the view that perceived reality is different from the measured reality that his predecessors sought to depict. When he tipped up landscapes and the tops of pots and vases it was because he believed that he was painting what he saw, even if he had to cheat to do so.

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Introductory to Chapter 15

Colour constancy is by no means the only constancy of visual perception. There are many other constancies and all are fundamental to the ability of the eye-brain to make practical use of visually acquired information. Paradoxically, although their name suggests stability, they are responsible for the veritable “shifting sands of appearance” which, in its various guises, constitutes one of the main problems for artists seeking to obtain accuracy in drawings or paintings from observation. This is because they ensure that, when we look separately at any two similar features of appearances whether they be whole objects, parts of objects, sections of contour or colours, there is a very strong tendency to see them as being more similar to one another than objective measurement would dictate – often a great deal more so. Our visual systems upset the measured parameters of external relationship by relentlessly forcing them towards normative dimensions and values. As a result, the constancies involve enlarging and diminishing, squashing and stretching, revolving, darkening and lightening and modifying colour. Any list of the constancies of particular interest to the artist should certainly include (a) size constancy, (b) shape constancy, (c) orientation constancy (d) lightness constancy and (e) colour constancy.

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CHAPTER 15 – THE OTHER CONSTANCIES

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Related chapters from “What Scientists can Learn from Artists”

Other Posts on colour and light in painting:

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local colour interactions

Introduction to the Post on “local colour interactions”

This Post is the second that offers a link to a .PDF version of a chapter from “What Scientists can Learn from Artists”. The purpose of making this more scientifically oriented information available on this website is to encourage readers to go deeper the ideas presented in my practice-oriented books on drawing, painting and creativity (see “Contents List” on the “Posts Page”). Chapter 11, the chapter featured here, focuses on new and unfamiliar things of potential value to artists that can be said on “local colour interactions”, a subject that has featured widely both in books and in the classroom. Its father figure is Eugene Chevreul, the Chemist at the Goblin tapestry works, who was responsible for the phrase “simultaneous colour contrast”,  and the best known publications on the subject are by Johannes Itten and Joseph Albers, both teachers at the Bauhaus. Of more recent books covering the subject, I can recommend “Colour : A workshop for artists and designers”, by David Hornung.

With so many authoritative writings on the subject, it might be supposed that I would have little to add, particularly since, as a general policy throughout my books, I have done my best to avoid wasting time on subjects that have previously been exhaustively covered in convincing ways. It is for this reason that my chapter on “local colour interactions” concentrates on subjects that do not appear in the publications of Chevreul, Itten, Albers, Hornung or, as far as I know, of anyone else. What I have to say is based on research triggered by the excellent teaching I received at my art school and issues arising in my own paintings. Its novelty comes either from original or less well know scientific research that deals with matters of potential interest to artists.

 

local interactions
Figure 1 : Nine discs contrasted with different coloured backgrounds, based on an Art School project that not only raised many questions but also triggered further investigations in the context of my own painting.

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The link to the .PDF file

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CHAPTER 12-BODY COLOUR AND LOCAL INTERRACTIONS

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colour contrast
Figure 2 : An illustration from a children’s book that led to an interest in colour interactions involving thin lines and over time to a number of surprising discoveries

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Other chapters from “What Scientists can Learn from Artists”

These deal in greater depth with subjects that feature in the volumes on the practice of drawing, painting and creativity.

Published chapters from book 2 of “Painting with Light and Colour”:

That is to say, the one that focuses on issues relating to local colour interactions, as opposed to how reflected-light influences appearances.

Other published Posts on colour and light in painting:

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Colour constancy demonstration

Colour constancy sets the ball rolling

It was unequivocal evidence of “induced colour” and “colour constancy” that triggered the realisation among scientists towards the end of the Eighteenth Century that colour is not a property of surfaces in the external world but phenomenon that is made in the head. Once this idea had been digested, it gained momentum and evidence began to pour in to suggest that all visual experience is a creation of the eye/brain combination. This game-changing paradigm shift was to lead, not only to the birth of the science of “visual perception”, but also to fundamental changes in the practice of artists,  either when drawing or painting from observation or when seeking control of pictorial dynamics. This is why the “constancies” and “simultaneous contrast dynamics” play such an important role in my books on the practice of painting and drawing. It is also an important part of the reason why I have written “What Scientists can Learn from Artists”, the last volume of my four volume series that explains the science behind so many of the ideas elaborated upon in the remaining three volumes. In going more deeply into the subjects that play such an important role in these books about artistic practices, it plunges us deep into the astonishing nature of the working principles of visual perception. Apart from the sheer wonder this must surely generate, knowing about the ways these determine how we “look” and how we “see” should have a significant benefits for artists: The deeper understanding and appreciation of the extraordinary things that are happening in our heads should help artists to:

  • Deal with the many practical problems that invariably face them when drawing or painting from observation
  • Make more creative use of their physical and conceptual tools.

The next Posts I will be chapters from the science volume.

A life changing event

This Post on “colour constancy” is the first from “What Scientists can Learn from Artists”. Its inspiration derives from Edwin Land’s irrefutable demonstration of the phenomenon of “colour constancy”, which proved to be a milestone in the search for an understanding of a subject that turned out to be of key importance to the understanding of how we “perceive surface”, “sense space” and are “aware of of lighting conditions”, all subjects of key importance to the ideas presented in “Painting with Light and Colour”.   

Below are:

  • A photo of the equipment used by Land for his epoch making colour constancy demonstration.
  • A reprise of the “Introduction” to the chapter and a link to a .PDF version of it (no need to read it twice: if you read it below, you can skip it in the chapter)
  • Links to Posts from “Painting with Light and Colour”, all of which (particularly chapters 7 to 11) have a debt to research that grew out of the colour constancy demonstration.

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colour constancy demonstration
Figure 1 : The set up for Edwin Land’s first colour constancy demonstration, comprising a multicoloured “Mondrian”, three light sources, projecting the three light primaries, and a telescopic light meter that could take intensity readings from each patch of colour separately.

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Introduction

As explained earlier, a key event in my life was the encounter with Professor Marian Bohusz-Szyszko. The ideas he shared set me off on a lifelong journey of discovery. My first step was to set about testing his seemingly extravagant assertion that it is only necessary to follow two rules to guarantee a good painting:

    • There must be no repetition of colour on the same picture surface.
    • All the colours used must be mixtures containing at least a trace of complementary.

After four years of experimenting, I proved, at least to my own satisfaction, that there is a special quality in all paintings that abide by these two rules. It is difficult to describe, but it involves the creation of a sense of pictorial space and harmony.

Fortunately, a troubling paradox arose that would eventually have a profound effect on the development of the ideas presented in this book. It concerned the Professor’s physics-based proof of the invariable variability of colours in nature. This asserted that no two parts of any surface will reflect exactly the same wavelength combinations into our eyes due to:

    • The complexity produced by the inter-reflecting surfaces
    • Variations in viewing angles and distances
    • Atmospheric filtering

The paradox is that, if the light reflecting from two parts of a surface can never be characterised by the same wavlength combination, how could artists repeat colours on a picture surface? Even if two regions were painted with exactly the same pigment-colour, how could these appear as the same?

Other people might already have known how to resolve this mystery, but for many years I had no idea how to do so. My first inkling of a solution came after many years, as a result of reading a paper by Edwin Land, the inventor of the Polaroid camera. In it was a powerful demonstration of the phenomenon of “colour constancy” and an attempt to explaining it. What the demonstration showed was a region of colour within a multicoloured display (henceforth referred to as the MCD) being perceived as remaining the same, even when the experimenter changed the combination of wavelengths being reflected from it. I was excited because here were two colours being perceived as the same despite reflecting different wavelength combinations into they eyes? For me it was a eureka moment. However a big problem emerged for it was soon clear to me that the explanation of the colour constancy demonstration suggested by Land was not neurophysiologically plausible. An alternative had to be found. I could never have guessed at the treasure trove of discoveries that would come out of my struggles to provide it. This chapter describes Land’s demonstrations in the context of an earlier attempt at explaining colour constancy. The next chapter introduces our neurophysiologically plausible colour constancy algorithm.

The colour constancy chapter

 

WHAT SCIENTISTS CAN LEARN FROM ARTISTS – CHAPTER 13-COLOUR CONSTANCY

 

Other chapters from “What Scientists can Learn from Artists”.

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Chapters from “Painting with Light and Colour”

Other Posts on colour and light in painting:

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