Saturday, May 15, 2010

The Optical and Conceptual: Components of Perception.

(Update 1/18/12) For a French translation of this post please click here for a downloadable PDF file: 

For this post I thought I would share a bit about a distinction that addresses problem solving for the artist in terms of how they "see." It involves two fundamental components that make up visual perception. I have come to know these components as "conceptual" and "optical." I have seen others allude to the same concepts using terms such as impressionistic (optical) and classical (conceptual).

One of my favorite art books, The Practice and Science of Drawing by Harold Speed, has a statement which I have often felt sums up these components quite well:

"We have seen that there are two extreme points of view from which the representation of form can be approached, that of outline directly related to the mental idea of form with its touch association on the one hand, and that of mass connected directly with the visual picture on the retina on the other."
Harold Speed, The Practice and Science of Drawing (New York: Dover Publications Inc., 1972) 80.
In the same book the author cites work by Michelangelo and Degas to further exemplify the distinction between the two concepts by offering the following (I have supplied an image for each artist although they are not the same images referred to in the book):
"In the Michael Angelo the silhouette is only the result of the overlapping of rich forms considered in the round. Every muscle and bone has been mentally realized as a concrete thing and the drawing made as an expression of this idea. Note the line rhythm also; the sense of energy and movement conveyed by the swinging curves; and compare with what is said later (page 162) about the rhythmic significance of swinging curves."

"Then compare it with the Degas and observe the totally different attitude of mind in which this drawing has been approached. Instead of the outlines being the result of forms felt as concrete things, the silhouette is everywhere considered first, the plastic sense (nowhere so great as in the other) being arrived at from the accurate consideration of the mass shapes."
Harold Speed, The Practice and Science of Drawing (New York: Dover Publications Inc., 1972) 66.

I sometimes like to think of the optical as the data our eye sees. It is compiled of non-representational shapes (masses) of patterns and color. It is associated with the 2-dimensional picture plane or an impression upon the retina. In contrast the conceptual is the mental understanding or visualization of what is being seen. It is the understanding of an object in terms of how the mind comprehends it based off prior experience or knowledge. It is often simplified or idealized to it make it easier to grasp. It is often associated with 3-dimentional, spatial, geometric and structural ways of thinking and problem solving. When this optical data is filtered through our conceptual understanding the result is our perceptional experience.

Ok, so why is all of this important. Well whether they are conscious of it or not it defines for many artists how they look at things and choose what to look for. Although greatly oversimplified, I have previously described impressionistic painters and classical painters thusly:

"The impressionist collects the data they see and presents the data to the viewer, who then draws a conclusion while the classical painter collects the data they see, draws a conclusion, and then presents the conclusion to the viewer."

More particularly when "seeing" how do these concepts define what artist's look for? Do they look for shapes(optical) or forms(conceptual)? Do they focus on the edges between shapes(optical) or the form's morphology between planes(conceptual)? Do they calculate the lightness or darkness of a stroke of paint by relating the values of various shapes(optical), or mentally visualizing the decay of light over a form(conceptual)? When they utilize a plum line, is it visualized structurally inside the object(conceptual) or at the picture plane like a line drawn on a window(optical)? When they start to draw a head do they start with the shapes they see(optical) or with some structural construct such as an egg form(conceptual)?

Realistically I don't think any artist's work is wholly formed conceptually or optically—although philosophically many seem to favor one approach over the other. For myself I think that all of the questions posed above, both optical and conceptual, are useful. I assume that they should lead me to the same conclusion. Yet that conclusion is formed by meeting my conceptually understood experience thus grouping me more as a classical painter as I previously defined it.

There is so much more that could be said on this simple distinction. However for the readers who are artists I hope it may make you more aware of how you see and for the art collector and enthusiast I hope it will give you more insight into the thoughts of the artists whose work you enjoy.

Just a little food for thought.

An Addendum passage from Harold Speed:

I have included a larger passage below from Harold Speed's book that ties into what has already been said. I wanted to add it on because it has been insightful to me but I couldn't see a good way of working it into what I wrote above.

"To sum up this somewhat rambling chapter, I have endeavoured to show that there are two aspects from which the objective world can be apprehended. There is the purely mental perception founded chiefly on knowledge derived from our sense of touch associated with vision, whose primitive instinct is to put an outline round objects as representing their boundaries in space. And secondly, there is the visual perception, which is concerned with the visual aspects of objects as they appear on the retina; an arrangement of colour shapes, a sort of mosaic of colour. And these two aspects give us two different points of view from which the representation of visible things can be approached.

When the representation from either point of view is carried far enough, the result is very similar. Work built up on outline drawing to which has been added light and shade, colour, aerial perspective, &c., may eventually approximate to the perfect visual appearance. And inversely, representations approached from the point of view of pure vision, the mosaic of colour on the retina, if pushed far enough, may satisfy the mental perception of form with its touch associations. And of course the two points of view are intimately connected. You cannot put an accurate outline round an object without observing the shape it occupies in the field of vision. And it is difficult to consider the "mosaic of colour forms" without being very conscious of the objective significance of the colour masses portrayed. But they present two entirely different and opposite points of view from which the representation of objects can be approached. In considering the subject of drawing I think it necessary to make this division of the subject, and both methods of form expression should be studied by the student. Let us call the first method Line Drawing and the second Mass Drawing. Most modern drawing is a mixture of both these points of view, but they should be studied separately if confusion is to be avoided. If the student neglects line drawing, his work will lack the expressive significance of form that only a feeling for lines seems to have the secret of conveying; while, if he neglects mass drawing, he will be poorly equipped when he comes to express form with a brush full of paint to work with."
Harold Speed, The Practice and Science of Drawing (New York: Dover Publications Inc., 1972) 47-49.


  1. cool post!...hey i may have asked u this before (so i apologize for not paying attention), but is this the only artist/documenter who has made this distinction between these two modes of perception? do u think this is kind of a modern convention, that is, from the time of the impressionists and spurred by the advent of photogrpahy. i am wondering not only where the language comes from but also where this optical/conceptual methodology applied to art practice has its historical base.

  2. Hey Carol,

    I don't think Speed is the only one to make the distinction. I think many people have noted this distinction but there are not standardized terms as far as I can tell. They all have slightly different takes but seem to be alluding to the same basic distinction. The terms "optical" and "conceptual" are terms I started using when I begin teaching and can not recall if I heard someone else use them or coined them myself.

    One of the first places I noted that there was some type of distinction was when reading
    Heinrich Wölfflin's (1864 – 1945) book, Principles of Art History. He uses the terms "linear" (conceptual) and "painterly" (optical) and begins to draw contrasts between the two such as "closed form" and "open form" respectively. The terms make sense. In closed form the form of the objects are clearly separated from their surrounding forms (think clearly established contours for an object) whereas in open form the edges are not so clear and there may not be a distinction between two objects (think of the shadow on a face merging with the background so one large shape of color is formed...very picture plane stuff).

    Juliette Aristides seems to make a similar distinction to optical and conceptual in her book Classical Drawing Atelier with the terms "impressionistic" and "classical."

    The neuroscientist David Marr seems to be dealing with something related in the theories he put forth regarding vision as the input moves from 2d to 3d perception. But it is not a topic I know much about.

    I suspect that this distinction becomes more clear historically with advances in optics and linear perspective but I really don't know. I would welcome anyone who knows more about the subject to please comment.

  3. Very nicely written Douglas.

  4. Douglas,
    Darren Rousar pointed me to your blog. I am trying to get into a discussion with “classical realists” or “academic revivalists”, about something related to the issue you are bringing up here.

    You wrote: “I don't think any artist's work is wholly formed conceptually or optically”.

    The dichotomy ‘optical / conceptual’ seems to correspond to a debate within classical realism, which I have called ‘optical / constructivist’. It is not exactly the same thing, because it does not correspond to Speed’s ‘outline - form’ distinction, but to way of approaching representation: strict observation on the one hand, versus observation followed by a degree of interpretation on the other, or a certain consciousness of building the form with the tools of representation rather than simply reproducing or copying what is seen.

    This, like the Munsell system, suggests a problem with respect to traditional painting practice, which I have tried to address in several places, including here:

    and, more thoroughly, here:

    As I once asked Graydon Parish; what is the place of “composition” in this approach to painting - assuming that “composition” is more than an mere arrangement of objects to be represented? What, in other words, is painting beyond a more or less charming optical illusion? What about painting which, though highly representative, is as far from optical illusion as possible, such as Manet, Whistler, Turner or, for example, Hogarth’s Shrimp Girl:

    …long considered one of the greatest masterpieces of all time - though largely neglected today?