About Art

An attempt to integrate cognitive sciences with art making.

Thursday, September 4, 2008

How To Draw What You See

It is commonplace for beginning artists to be advised to paint "not what they know but what they see. " The problem is understood to be that the novice has a "literal" approach versus the "visual" approach of the advanced artist. The argument goes that we "think", for example, that trees are round green forms, and therefore the beginner paints them the color and shape he thinks them to be: the tree is portrayed as something that resembles a green lollipop. This misperception of the object in spite of visual evidence to the contrary so impressed psychologists Cohen and Bennet in their article "Why Can't Most People Draw What They See?" that they suggested that it was delusional in nature. (footnote 1) What's equally as delusional is the explanation put forth by current day art instruction which I just summarized.

Paradoxically the advice to "draw what you see" is hard to follow. Beginners struggle with it assuming that they are just so accustomed to relying on words, a "literate approach", rather than vision, a "visual approach", that they can't abandon their old habits. It is hard to understand why anyone would believe that the word "tree" should influence the beginning artist to draw a green lolipop. However, like a great deal of theory taught in art school this notion of the literate versus the visual is, at best, based on obsolete19th century ideas. For unknown reasons the art world and the world of scientific studies of vision and cognition have remained isolated from each other. Much could be gained in both fields by more discussion between them.

To begin with, identifying the problem as one of "seeing" or not seeing as the case may be, just isn't accurate. What an artist making representation art is doing is looking at the subject, turning away and looking at the canvas, and then making a mark. This is not about a visual task or for that matter a verbal task. It is a memory task. It involves what is called visual memory as opposed, for example, to verbal memory. Hence my somewhat reversed title: " how to draw what you see" is wrongly put. "How to remember what you see in order to draw it" is more to the point.

But what's so hard about remembering what you see for the minute or two it takes to "attack" the canvas with brush and paint? The hitch is that there are two types of visual memory, short-term visual memory and long-term visual memory, and here's where the contribution of cognitive comes in. It is only in short-term visual memory that an accurate, specific, and particular visual image of the subject is held. In contrast, long-term visual memory stores simplifications and interpretations of images like the lollipop tree that are not appropriate for making realistic representations. Unfortunately short-term visual memory is really short and limited, so short that the image is lost soon after one turns to the canvas and so limited that it can hold only a small bit of the subject. So it is not that art students are substituting what they know, "verbal memory", for visual memory. They are substituting long-term visual memory simplifications and interpretations for short-term visual memory. To repeat the major task of making a likeness is a short term visual memory one.

The importance of grasping this way of looking at the problem of making representational images lies in the fact that it can explain what beginning artists need to learn to do, why and how certain techniques work, which ones seem to be better than others, and, perhaps, generate new exercises, methods, and research.

Short-term visual memory
Short-term visual memory has three drawbacks. It cannot record all the visual information that bombards us, that which it stores it does so for a second or two, and it is not generally "interested" in the minute detail that an artist needs.

It simply would be impossible to store "photographic quality" images of all the real world scenes that fall on the retina any more than this could be done with a camera. It would not take long for both the brain and the camera to run out of storage capacity. In fact, short-term visual memory is quite limited in what it can hold. It cannot hold the entire image that falls on the retina. It holds a surprisingly small area of the scene in front of us. Drawing an eyebrow in one study involved looking at it three times to refresh short term visual memory. So short-term memory's first drawback is the limited amount of real, accurate visual information it can store long enough to be useful to the artist.

Short-term visual memory's second drawback is obvious from its name: that what it does store deteriorates rapidly, in fractions of a second, and has to be refreshed often.

There is a third drawback to short-term visual memory. When we look at a scene we tend to "scan" it whether it's a landscape, in which case we seem to be scanning to make sure there are no predators lurking about, or a person in which case we are trying to obtain from body language or facial expression as much information as we can about them. Just ask any woman about this. The point here is that, to look three times at an eyebrow or anything else in order to depict it in our art work, we have to resist the tendency to look all over the place. This is much harder to do than it seems.

Long-term Visual Memory
It is in long-term visual memory that the image is stored pretty quickly in such a way that it can be held for a long time and retrieved easily. Unfortunately, to do so the image is transformed from a specific representational image of which an artist would want to make a copy into a generic interpretation sometimes called a "schema". A schema resembles its subject in much the same way that a map resembles a landscape and like a map, although it is very useful, it is not a "picture" of the thing mapped. The satellite image does not resemble the map. This transformed image which we remember "seeing" often resembles what children draw.

"Schematic Pressure"
The problem, of course, can be subtler. Schemas can creep into small parts of drawings, and it is a never-ending task to be alert to them. For example, if short-term visual memory is not constantly refreshed and held focused on particular passages, an artist can easily slip and make the iris of an eye round even in three-quarter view or profile.

Fundamental to making representational art is to realize that there is a constant tendency to use the image (schema) we have in long-term memory rather than the more limited and fleeting one in short-term memory. One way to put it is that there is a kind of pressure from schemas to get out and into our art work. If we look at a tree, we can keep in short-term memory only a fragment of that tree for only a brief moment. If we are drawing a limb, we have to constantly return to each new segment of that limb to refresh short-term memory. If we don't, the "schematic pressure" from long-term memory will substitute a simplified and cartoon-like image of tree limbs in place of the real thing.

Representational artists have learned to use short-term or what is sometimes also called more aptly, "visual working" memory. This would at its most simple form require looking many times at small areas of the subject. They must have also learned to not use the long-term memory schemas. But how do they do it and how did they learn it? Answers can be divided into those that are related to improving short-term memory and its rate of refreshing and those that related to decreasing the power and simplicity of long-term memory schemas. The following is not intended as a comprehensive survey, but merely illustrations of how the paradigm suggested above might be applied.

Refreshing short-term visual memory
There is some evidence to suggest that short-term visual memory can be improved by practice. There is an apocryphal story of a French teacher of painting who posed a model on the ground floor and had students set up their easels four stories above it. They had to run the stairs over and over again trying to hold in short-term memory what they wanted to paint. Whether it was better for their cardiovascular conditioning or their art-making is debatable. The opposite, however, is clearly helpful. The less time there is between the look and the putting of a mark down on the artwork the better. John Singer Sergeant's portrait technique would be a case in point. He put his canvas directly beside the subject, somewhat like we do with the sight-size method, and stepped back quite a ways to get visual information in short- term memory. Then he would rush forward to put a mark on the canvas before the short-term visual image deteriorated.

The admonition of one of my teachers that a brush is not an "automatic weapon" and should be used only once before being "reloaded", also seems apt. Here, by restricting oneself to one mark before looking again and refreshing short-term visual memory, it is easier to prevent substituting long-term memory schemas for short-term memory image fragments. "Three looks, two thinks, and one mark" is how it is sometimes said.

It is not only a question of what to do but, also, what not to do.  With enough practice, the artist learns not to move his pencil if he's going beyond what is or was in short term visual memory and to look again.  When to stop the line and look again is the critical moment of insight in drawing representational images.

In drawing a likeness some teachers suggest drawing what might be called a vector diagram. Even if the aspect of the subject to be drawn is a curve, these teachers suggest drawing from point to point and smoothing out the shape later. Helen Van Eyk's reason for suggesting this approach to students was "They look more often" because they break the image down into multiple segments. We now know that means that they refresh short-term memory more, and it is this that recommends this technique over all others.

Contrary to the standard advice thinking "verbally" about what you are looking at seems to help. People with no artistic training tend to scan with a free-floating attention even when they are specifically instructed to make a realistic image. For example, if they are asked to make a portrait of a face, they still do not look at any one form. Studies of which part of the brain is active do not suggest that they are thinking about anything in particular. Paradoxically the visual part of the brain is most active just as the standard advice suggests. On the other hand when a trained artist is asked to make a portrait, he or she tends to zero in on one particular form, and the thinking part of the brain is quite active. This has been demonstrated by having an artist and several non-artists attempt to draw a portrait while simultaneously having a functional MRI of the brain which can determine what parts of the brain are most active.

It is much easier to keep focused on a specific part of a subject if we can think of questions about it, questions that often come from the canon of proportions. If we can look longer, we can hold the image in short-term memory longer. If you try looking at a small part of an image, you will be able to feel the urge to move your eyes to other parts of the form or subject, to fall into the scanning mode. On the other hand, if you are thinking about a question such as "Is the upper lip half as wide as the lower lip?" (From the canon of proportion) you can focus your attention better.
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Reducing or Improving Long-Term Visual Memory Schema
Knowledge of the canon of proportions whether it is of the figure or the artistic anatomy of trees will enrich long-term memory schemas. It will change the green lollipop into a more complex cliche but not into an image that looks like the tree before us. Just depending upon the canon of proportions, of course, will produce a realistic-looking "academic" image but not a portrait image. The resulting image will look better, but it will suffer from the same problem of schemas replacing realistic images. It is not useful for the purposes of making a representational image by itself.

If, when painting a portrait, we focus on depicting the shadow shapes, the darks, and focus intensely on them, we are not dealing with anything that is stored in long-term memory as a schema. The shadow on the side of the face over the eye socket and down the side of the nose is a one-of-a-kind form. Because we are not drawing the nose or the eye, but the shadow shapes pressure from schemas is greatly diminished. There may be some pressure to make squares and triangles out of the shadow shapes, but this is much less powerful than the schemas in long term visual memory of the eye and nose. In addition we have to look more frequently because there are no prototypes in long-term memory to fall back on, and there are no canon of proportions for shadows. The portrait emerges in the negative spaces. Emphasis on drawing or painting "the light" rather than the forms has the benefit of bypassing the simplifications of long-term visual memory schemas.


Final thoughts
The artist does not employ short-term visual memory in order to make what a photograph or a plaster life cast would display. It is not an exact portrait or what has come to be called a "photographic likeness" that the artist should be after but a "super portrait". The artist is capable of making an image of a person, tree, or landscape that reads to the brain more like the image than the thing itself. Once one has mastered the "how to look", this is the next challenge. And cognitive science has something to contribute to this as well. I discuss it below in another post.



1 Cohen DJ, Bennet S why can't most people draw what they see? J Exp Psychol Hum Percept Perform. 1997 Jun;23(3):609-2

Wednesday, September 3, 2008

of interest in terms of how the mind sees

The following is a message in which the letters of the words are scrambled. Only the first and last letter are correct. Don't worry you will be able to read it. The same principle applies to painting and looking at portraits. Only certain things have to be in the right place.

fi yuo cna raed tihs, yuo hvae a sgtrane mnid too

Cna yuo raed tihs? Olny 55 plepoe out of 100 can.

i cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. The phaonmneal pweor of the hmuan mnid, aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it dseno't mtaetr in waht oerdr the ltteres in a wrod are, the olny iproamt nt tihng is taht the frsit and lsat ltteer be in the rghit pclae. The rset c an be a taotl mses and you can sitll raed it whotuit a pboerlm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Azanmig huh? yaeh and I awlyas tghuhot slpeling was ipmorantt!

quotes about seeing and making art


These quotes about the post just above it in this blog were gleaned from the twice-weekly email newsletter by Robert Glenn at www.painterskeys.com. Some of them support my opinions and some of them are good examples of with what I disagree.


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The painter draws with his eyes, not with his hands. Whatever he sees, if he sees it clear (sic), he can put down. The putting of it down requires, perhaps, much care and labor, but no more muscular agility than it takes for him to write his name. Seeing clear (sic) is the important thing. (Maurice Grosser)

Paint what you see, not what you know. (Charles Hawthorne)

When you paint, try to put down exactly what you see. Whatever else you have to offer will come out anyway. (Winslow Homer)

Fundamentally, art is a way of seeing rather than of doing or making. (Alan Jarvis)

My work isn't about form. It's about seeing. I'm excited about seeing things, and I'm interested in the way I think other people see things. (Roy Lichtenstein)

It takes time to really see. Seeing is in itself an art. Perhaps that is what art is, the crystallization of a vision. (Mary Jean Malleux)

Any fool can learn how to paint. The trick is to learn how to see. (Dorothy MacCarthy

On the face of it, the easiest of all activities should be seeing what we see. In reality, it's the hardest. (Charles Movalli)

If only we could pull out our brain and use only our eyes. (Pablo Picasso)

The thing known and the thing seen are not the same. (Harriet Shor)

The mind stands in the way of the eye. (Arthur Stern)

Tuesday, September 2, 2008

facial recognition

To make a portrait you can benefit from some understanding of how people look at and recognize faces. There are two types of recognition systems: visual and emotional.


visual recognition of faces
Visual facial recognition occurs in a special, dedicated part of the brain: the fusiform gyrus in the right temporal lobe. Recognition of most other things occur elsewhere in the brain. So portraits go to a place in the brain that landscapes, still life paintings, etc do not go.

We have a great deal of information processing ("wetware") in our brains for facial recognition which probably includes facial expressions and body language as well. This is why figure drawing and portrait drawing are such a good exercises. Because we have this area of our brain dedicated to the task, we can tell very easily when there is a mistake. John Singer Sargent said that a portrait is "a likeness with a little something wrong around the mouth". I take this to mean that the brain's facial recognition ability can defeat even the best of us.

It is much harder to spot something a little wrong, for example, with birds or even rainbows. In fact, many of the great artists painted and drew birds very badly. If, however, you happen to be a serious bird watcher, bird identification probably goes to the so-called facial recognition area also (it is obviously not only for faces but for recognition tasks that are important to the person). Consequently, you will probably be able to draw birds better than non bird watchers because you can be more critical of your results using the "facial recognition" part of the brain. Reubens has a rainbow in a painting with the colors going the wrong way.

On the other hand, if you turn a portrait upside-down, the image is not recognized by the brain as a face and does not go to the face recognition area but to the general recognition area. This can be helpful sometimes as all artists know.

Some computer programs searching video tapes for faces do so by looking for the color orange as understood by the computer which includes a dark valued orange which happens to be how the computer sees African American skin color. However, it is thought that the brain recognizes a face as if it were a barcode by looking at the pattern of light bands on the face, just this coarse pattern. This is similar to the artist's understanding of color and value on the face: forehead light, middle of face darker and redder, and lower part of the face gray even in women. This set of three "bars" switches the image as it travels from the eye to the face recognition area.

The interesting thing about facial recognition is that some people are very good at it and some people are terrible at it. There are several tests for how good people are recognizing faces available on the internet (google "face recognition test"). At the very worst end of the spectrum there are people who are "face blind". This normal variation of abilities seems to run in families, appears to be a dominant gene, and more males have it than females. One estimate is that about 1 in 50 people have a significant degree of face blindness.

This can create a problem for an artist if his client has some degree of face blindness. For example, on tests of facial recognition, I do exceptionally well. My wife, on the other hand, is poor at it. The other day, I used what I thought was an "interesting" photograph to do a portrait of a friend. I showed it to my wife who couldn't recognize who it was. Before I got upset it occurred to me to show her the photograph. She couldn't recognize who it was from the photograph either. I have to be careful to make a portrait that the sitter can recognize. In this case a sketch or a photograph could be useful to test if that particular view reads well to the sitter.

There can also be face blindness as a result of disease. In this case it is usually a blood clot in the part of the brain responsible for facial recognition. In medicine it's called "prosopagnosia" from prosopan=face and agnosia = lack of knowledge --from Greek roots. There are thought to have been about 200 known cases with two of them people who were born with it. It is a very profound condition in which people cannot recognize photographs of themselves or their image in a mirror.

emotional recognition

We learn about this other sort of facial recognition from some serious brain problems that some unfortunate people have called "delusional misidentification syndromes.". In Capgras syndrome the person thinks that someone well known to them has been replaced by an identical impostor. In this case the person recognizes the person very well, but doesn't believe that they are who they are. There are several variations of this syndrome. For example in mirror self-misidentication the person believes the image in the mirror is really someone else. In both cases there is no problem with visual facial recognition.

The explanation is that there is an emotional response to familiar faces that appears to be entirely separate from the visual recognition task. People who are totally face blind and who cannot say who a picture is supposed to represent, have a physiological response that can be measured by the type of responses that lie detectors use. For example, they might breath a little faster or their galvonic skin response might change when shown a familiar face.

The people suffering from delusional misidentification syndromes don't seem to have the physiological response to faces that the rest of us have. They recognize the face but it doesn't read right to them hence they have to explain it in peculiar ways like the person is a substitute for the real person, an impostor.

conclusion

E. H. Gombrich , the art historian, has asked whether a portrait is supposed to look like the sitter or, instead, evoke the same response we have to the sitter in real life. It's an interesting question since many of us look at portraits whose subject we never knew and still like them. My wife, who I earlier mentioned is not particularly good at facial visual recognition, is very good at picking up emotional responses to portraits. The other day we were looking at a small Velasquez portrait, and she said, "Boy, I wouldn't want to cross that guy!" I could "see" or should I say feel what she meant.

Gombrich's question can be asked of just about every picture. Some artists are better at communicating the emotional response and some are better at communicating the visual response. Charles Burchfield, for example, clearly tried to paint landscapes that evoked the emotional response. See www.artcyclopedia.com/artists/burchfield_charles.html for a listing and links to specific paintings and drawings. It, obviously, isn't an either or situation, but there can be too much emphasis in what is said on the visual aspect in art instruction and not enough on the emotional response.

I can see a problem with Burchfield's approach. I happen to like his work very much, but I spent a great deal of my childhood in the woods getting the same feelings that Buchfield seems to be portraying. But, if the viewer has no experience of this, he doesn't find a center of interest in Burchfield's work. It's safer to have more visual recognition in a painting.

Monday, September 1, 2008

super portraits

a "superportrait" is an image that is paradoxically more like the person than the person themselves

A GOOD REFERENCE
Superportraits: Caricatures And Recognition (Essays in Cognitive Psychology) by Gillian Rhodes (Hardcover - Feb 1, 1997). It's now out of print and expensive to buy, but it is in many psychology libraries.

morphing software
To understand superportraits you have to be familiar with what is called "morphing" software. This software, about ten different programs are available, some without charge, over the internet, will make a series of images seamlessly transforming one image into another with all the steps in between available to see. One of the classical illustration of morphing is of the transformation of the face of a beautiful woman at one end to the face of a cheetah at the other. In between are images that look somewhat like the cheetah and somewhat like the woman. Below are steps 5 through 16. Step 1, not shown, would just be the picture of face of the woman.


step one: using morphing software to make an average face

There are, of course, many uses for morphing software. In this study the goal is to morph a great many photographic portraits into one. The result will be the average image of all the faces.
Individuals do not have perfectly average faces, but from a large collection of portrait photographs about the same size, you can use morphing software to combine several hundred faces all together. What you get is an image in which every feature you can think of, for example the nose, will be the average shape of everyone's feature, everyone's nose. This average face is not beautiful or striking. It doesn't call attention to itself, but it is a pleasant-looking face.

step two: morphing the average face with the face of the subject sitting for a portrait
If we now use a new specific individual as a portrait subject and the average face we developed above, we can do two types of relevant morphing transformations. We can make the subject's face more average. The result is called an "anti-caricature". Or we can exaggerate the subjects features by moving the image away from the average. This is called, of course, the "caricature". Most people are familiar with extreme caricatures, but in this case we do not overdo the caricature distortion. If the nose is longer than the average, we lengthen it some more but not enough to be recognized as a distorted photograph. We make the nose longer but keep it still within what might reasonably be seen in real life subject. Another example might be making someone slightly more bald than they actually are.
We will now have three photographs of our portrait subject to play with:

the anti-caricature -- a more average face
the caricature -- a less average face than the subject actually has with more exaggeration
the real picture of the subject -- the actual face without any changes


Here is a set of anti-caricatures and caricatures of Rowan Atkinson, the comedian. The image is a little small. The top center is an unaltered photo, on the left the column is increasingly normalized images, and on the right is increasing caricatures.




step three: the critical experiment


This experiment was done by S.E. Brenner for her masters thesis at the MIT Media Lab and published in Leonardo 18, 170-178 in 1985 under the title "Caricature generator: The dynamic exaggeration of faces by computer".

We now take these three pictures and ask the portrait subject and people who know him or her well which of our three photgraphs is most like the subject, which photo is the best likeness. We also test to see how long it takes for the person to be recognized in each of the photographs.

1. The anti-caricatures, the face made more normal than it actually is, is much more difficult to recognize, taking 4 times longer to recognize than the caricatures. I conclude from this that any effort to "pretty up" a portrait there will be a certain recognition cost. If you have an ugly face to make a portrait of, you will loose likeness by toning down the ugliness.

2. But more impressive is that the caricature is recognized twice as fast as the veridical image, the image that was not morphed either way. Even the subjects think the caricatures resembles them better than the real photographs.

We, therefore, have with our caricature what has come to be called a "superportrait", one that we can truly say is "more like the person than the person themselves". I conclude from this that the artist's job is not to make a likeness of anything (portrait, landscape or still life) but a super-likeness.

The immediate question I suppose an artist would ask is whether morphing software would help painters. Well, it probably would given how much we depend on photography, but the problem lies in obtaining the average face from which to create the caricature. We would have to ask with whom our portrait subject is going to be compared. There are a lot of practical problems. The group of face pictures we are going to morph together would have to be adjusted to the group from which the subject comes, that is for age, gender, class and race. It wouldn't work to morph an old man's face to a norm that is made from young faces. On the other hand, there is not an infinite number of groups from which subjects come, so it is possible that someone might do it.

Failing to develop this sort of software, I think the lesson is that, when working from a photograph or a model, there comes a time when you should stop using them and just develop the painting itself with what has been said above in mind.

how do we explain superportraits being better than exact portraits?

I think that exaggeration (which is what is meant by superportrait above) is one of three factors in making a super-likeness.

1. Little detail: too much detail leads to the frozen, expressionless look so often found in realistic portraits. Soft edges, particularly at the periphery, help. Air brush art is all soft edges and works quite well. Some sliding off the exact color up or down the color wheel, pushing green a little yellow at the edges for example, also reduce detail and increase the viewers ability to see the image as real.

2. simplification: recognition works when features are omitted (a portrait without eyes, for example, can be identified as such and such a person) but fails badly if the artist gets a feature wrong.

"From a slight underdetermined drawing, where the ideas of the composition and characters are ... only touched up, the imagination supplies more than the painter himself could possibly produce; and we accordingly often find that the finished work disappoints the expectations that were raised from the sketch." Joshua Reynolds (1723-92)

3. exaggerations: The brain does not identify a face by matching the image in the eye to a photo album of snapshots of faces stored in the brain by, for example, putting one image over the other and seeing if the features line up. What the brain does is use information processing. In an oversimplified example what the brain has is a "program" with questions like "is the nose long?". If it is someone with a long nose, it goes to the section of the program on "people I know with long noses" and asks other questions to narrow down the identification. Such a program uses much less memory than a photo album would. Where exaggerations, less detail, and simplification come in to help is, if the nose is made a little longer than it actually is as well as easier to recognize as a nose because it is simple and does not have extra detail, the program can get through the "Is-this-a-long-nosed-person?" step quicker. From the point of view of the brain, a better likeness is one it can identify quicker and easier. Interestingly Degas always painted his self-portrait with a longer nose than he actually had (we have photographs of him) and it is not clear whether he thought he looked more aristocratic or intuitively knew it was a superportrait.

There are some interesting historical facts. It is not that we have just discovered the useful of exaggerations.

The word "cartoon" is often used today in a way similar to caricature. However, most artists know the word as a preparatory drawing that will be used to transfer a composition to a wall for a fresco. It comes ultimately from the French and Italian, "carte", for paper and the italian "cartone" meaning pasteboard which is thicker than usual paper close to what we call "card stock" now. It's use in the modern sense comes from a humorous drawing from a 1843 Punch Magazine which depicted the House of Parliament fresco competition which was done by judging the cartoons submitted by the artists. But the drawing was itself labeled "cartoon" in Punch. The public apparently didn't know the meaning of the word, and from then on used it to refer to humorous drawings in magazines.

Deliberate exaggeration in an image of a person could only occur after there was a clear separation in people mind between the fate of the likeness of someone and the person themselves. Image magic is still one of the most widespread spells (burning in effigy, for example.) This freeing of the fate of the image from the person it depicted only occurred in the late Renaissance producing mannerism and caricature, a term coined by its first practitioner, Annibale Carracci.

"It [a caricature] is a likeness more true than mere imitation could be. And caricature, showing more of the essential, is truer than reality itself. This paradox is no means only an empty phrase...It reveals a new credo which is characteristic of the century in question". Ernst Kris.


Friday, May 23, 2008

THE COMPOSITE APPROACH VS. THE HOLISTIC APPROACH TO PORTRAITS

Help with portrait painting comes from unusual and surprising places.  Two recent studies give us something to think about.

Everyone is familiar with the witnesses to crimes being asked to describe the perpetrator's face.  Whether it's a police artist or software, the usual approach is to attempt to assemble a remembered likeness feature by feature, what is called the "facial composite" approach.  ("Did he have a mustache?  Was it thick or thin?")

This is, indeed, one of the ways to go about making a portrait.  Here in New York City it is most often seen in street artists many of whom were highly trained in China although one of my early teachers suggested this was the easiest way, and he was trained here.  Usually one begins with one of the eyes.  This distance between the eyes is usually the length of one eye, so it's easy to put the other eye in.  One then measures from there to the other features in hopscotch fashion, and puts in the outline of the head last.  You can get a quick likeness, but there is something stiff about it, something that is just not satisfying.  In the case of the eyes, they sit on the surface rather than in the eye sockets even if after the fact attempts are made to put in lines suggesting it.  One of the things you don't do in this method is squint because it obscures the features.

Well, it turns out that the facial composite approach to trying to get a witness to describe another person simple isn't much better than trying to draw a portrait this way.  While the composite way of drawing a portrait is unsatisfying but recognizable, the facial composite software or artist's drawing of a remembered face is neither recognizable nor satisfying.  When people were asked to make a composite of a well-known celebrity this way, only less than 3% of viewers could identify the person from the composite.  The use of this faulty composite method is a serious problem.  Of the first 180 people exonerated by DNA testing about 80% were falsely convicted based on witness misidentification.

Another approach is now being tried in  police work that is called the "whole face" method.  This one begins by showing people different types of complete faces  -- square, round, heart-shaped, etc .  The witness picks the "parent face" that most resembles the perpetrator from a display of about 5 other faces and then looks at different subspecies of this parent face until they can't get any further.  This is beginning to look more promising for facial memory.  Interestingly overall facial or head types are discussed all the time by hairdressers, and that's where you have to go to get more information about general head shapes.  For example, the heart-shaped face with a small chin can have hair cut at the level of the chin to square up the facial outline a bit whereas the square-faced person with a strong, broad jaw would look terrible with this type of haircut.

Evidence is now accumulating that faces are processed, stored, and retrived at what is called the holistic level not at the level of individual features.  This is probably the way we should draw and paint them.  Artists who used to use a very out of focus slide to block in the head were probably on the right track.  Returning to drawing or painting the eye, Sargent used to say that he painting the eye socket and then slipped the eye in like a poached egg at the end.  In this method the more you squint in the beginning the better.  I think it's a good idea to think of yourself as trying to first get the "parent face" painted.  Instead of trying to draw the features I've been experimenting with (after I get some construction lines down) just drawing a smudge where the eye sockets should be, and if this is correct I might go back after a few other smudges like the shadow on the nose and try to define the eyelids and then the pupil.

(Association for Psychological Science (2007, Feb 11) Facial Composite Systems Falling Short.)

There is another recent study of visual short-term memory which I wrote about in my first post in this blog.  The scientists found that, if people were given a little more time to look at them (4 seconds) they were able to remember more facial images than other things like cars and watches.  On the other hand, if people were given a short amount of time (half a second), they did worse at facial memory.  Once again the assumption is that faces are stored in a complex holistic fashion hence the need for extra time.

Most important and potentially extremely hopeful for us artists is that they think this supports the idea that short-term visual memory can be trained.  That is we seemed to have learned to store faces better in short-term visual memory than other things, so why not other things or more of an individual face.  James Gurney of Dinotopia fame, who has a great bog on art and art making, occasionally mentions that he has trained himself to be able to hold in short-term visual memory more and more of the subject I think by merely looking at the subject and looking away and trying to draw as much as he can.  It's worth trying.

Vanderbilt University (2006, Dec 12)  Why we "Never Forget a Face" Science Daily, May 21, 2008.

Tuesday, April 22, 2008

THE IMPORTANCE OF THREE-DIMENSIONS

MARCUS BLATTERMANN who has a website that translates from the german to, I think, food with sauce (which may be a idiom of some sort) made an interesting experiment with portraits. See http://essenmitsosse.de/likeness-in-portrait/

He first did an outline drawing of a familiar face (President Bush) which was almost unrecognizable although an accurate drawing of the "profiles" of every form on the face.  He then did an outline drawing of the shadow shapes which didn't read either.  The picture that worked best was a rather crude black and white posterized version of the photograph which allowed one to read the three dimensional shapes of the face without much detail.  This was the best likeness.

His conclusion was that what the feature detectors in the brain's facial recognition centers are looking for is three dimensional forms.  For example, a nose is a protuberance from the face with a very particular three dimensional form.

It's a very interesting idea, particularly important when working from photographs which temp one to draw linearly.  In a portrait workshop with Leslie B. Demille he made a point of never drawing a line, but drawing an edge between two forms.  For an extreme example an elderly person with lots of "lines" on his or her face is best done by putting down multiple wide marks on one side of the "line" and other broad marks on the other side of the "line" with a little space between the two series of marks that allows us to see the underdrawing.   The underdrawing peaking through  the edge between the two passages  is, of course, what we call a "line".  In reality a line of the face is a three dimensional fold, and this method represents  them best. 

I think Bitterman is on to something here about how the brain reads portraits and how we should think about what we are doing.  This brings up the question of what it means to "draw three dimensional forms" with lines.  It's not just putting in the form shadows or the cast shadows.  In fact, I think it may have less to do with the shadow shapes than we think.  For some strange reason, when you think about drawing some form in three dimensions, you draw it differently than when you think of drawing the idea of the feature itself (nose, arm, etc). 

 What interests me is that I have seen innumerable didactic figure drawings in which there is, in addition to the figure, an arm or leg off to the side which the teacher has cut in half to show that it is a cylinder.  However, if you really were to draw a cylinder with the sides exactly parallel to each other it would look more like a robots arm than a human arm.   If you put in too much technical shading with the core shadow and the highlights running up and down the arm, it also looks like it's made of metal because that's how very reflective surfaces work, not the way skin works.

 In fact, when you think "the arm I'm drawing is a cylinder-like form", what you do is related the curves of the two outside edges to each other .   They bow out a bit like a soft shape, perhaps like the long thin balloon, not like a metal cylinder.  So, perhaps, what we do is to integrate the lines all over the form more when we think "three dimensions."  Consider how one might draw a nose.  The wrong way would be to draw from point to point down one side, around the bottom, and up the other side even 'though that is the easiest to do and would accurately outline the form.  This is what you would do with tracing paper over a photograph.  It would look like Blattermann's first try. The right way would be to draw both sides of the nose at the same time.  Sounds impossible, but you would come close if you would keep you pencil on the paper and circle it around the biggest nose shape, lets say the overall length of the nose, then add another aspect of the form the same way, the circular bulb at the base of the nose, keeping the lines light. There would be some lines that you will have to take out, for example at the root of the nose because, in keeping your pencil on the paper, you have left a line there, but the end result is more three dimensional and reads like a better likeness.   In doing it this way there are some fairly  faint lines that you would never think to include that help to make it three dimensional.