Vision and Art: The Biology of Seeing by Margaret Livingstone: CLIFF NOTES
Having read this book I’m going to post some of the key things I learned here. This may or may not be helpful but, since the notes would otherwise just be on my computer, I thought I might as well publish them on here. It may be however that my notes are more complicated than the book itself, which you can find on Amazon: https://www.amazon.com/Vision-Art-Biology-Margaret-Livingstone/dp/0810995549
I would definitely recommend this book to art students since it deals with a range of topics that are fundamental to how the human eye perceives things. I will say however, that it can be difficult to read at times.
For example, I often had to re-read paragraphs to try and work out what was being said. I think this is partly to do with the fact that vision science is still very poorly understood, and perhaps partly because the author, a scientist, didn’t want to ‘bore’ art students with long explanations and so kept things concise. Personally however, I would have preferred a bit more prolonging of the explanations, as like I say, the author would often move on and I would have to stop to try and understand all that had been said.
The reason I mention this is not to criticise the book but simply that I don’t want to recommend it to people without giving them advanced warning that it can be a little tricky at times. That said, otherwise it’s very good. All of the topics are very pertinent to art, there are lots of diagrams and pictures so the book is not as long as you might think (its only 200 pages anyway) and I learned a lot about the science of vision from it.
Below I have summarised some of the key take aways from the book.
Chapter 1: About Physics of Light
1) There are huge differences between the wavelengths produced by paints and objects of the same colour.
The idea that you can paint a tomato the same colour red as it actually is is essentially impossible. Tomato coloured pigment paint simply doesn’t and probably cannot exist. Luckily however, as we learn later in the book, the eye is rubbish at precise colour detection, and works largely on a relative and comparative basis. These two facts somewhat ‘cancel each other out’.
2) In the future a new form of painting may emerge where people scratch very small holes onto panels.
However for this to be done successfully, precision technology of the highest calibre will be required, so such an art form would be a digital art.
This technique would take advantage of the phenomena of light interference and diffraction. The beautiful patterns of light seen on the back of a CD are an example of this. As are the colours seen on a butterfly.
Chapter 2: About the Eye
1) Vision Science is made difficult, not by the nature of light, but by the arbitrarily contrived mechanism of the eye.
To give you a metaphor, suppose you watch Vesuvius erupting. Now contrast that with being given an eye witness testimony of the event. Probably the witness can put a picture into your head. However, because of bias, they will tend to highlight certain things and neglect others. They might also confuse certain matters.
The eye essentially gives you an eye witness testimony of reality. But the eye is biased, selective and sometimes confused in its portrayal of reality.
The eye is to light, what humans are to physical reality. Way more complex but highly arbitrary, selective and biased.
2) For heightened realism, perhaps we should all paint on the inside of a soccer ball that has been split in half.
The viewer would stick their head inside the half-sphere, without touching the surface, and thereby have a 3D view, complete with peripheral vision.
3) Important difference between Violet & Purple.
Violet is a pure, spectral colour. In reality it is perhaps bluer than we perceive it, but because it happens to stimulate the red cones of the eye as well as the blue, we see it as a bluey-red.
I’m not sure there is any evolutionary need for the red cones to be stimulated by extreme blue light. Rather it seems like a flaw in the design of the eye, badly contrived due to evolution. The author says that violet pigments are hard to come by.
Purple on the other hand is a mixture of red and blue. According to the author, purple objects and pigments are also rare. This is because to be purple, you must reflect both red and blue light. Or in other words, you must absorb all the light in the narrow middle of the spectrum. This highly specific requirement is difficult to achieve and means that purple is rare in nature.
4) What is so special about primary colours? Nothing really, it’s just that the human eye has arbitrarily evolved to respond to the colours of blue, red and yellow.
When the eye is exposed to these colours, there is a specific cone that gets excited and relays a message to the brain. For any other colour, orange say, the red cone and yellow cone both become excited, and so the brain is sent a message which it interprets as a combination of yellow and red (i.e. orange).
(Infuriatingly, (as with a lot of vision science), the rods are known as blue, red and green (rather than yellow) but I omit that technicality here).
Chapter 3: About Luminance & Night Vision
1) The grayscale you see with your eye is different to grayscales produced by cameras, computers etc.
However the author suggests that the Panatomic X camera produces a grayscale similar to the human eye and that Adobe also produces something similar. (Of course we never see in grayscale but if we could remove colour we would).
2) The importance of capturing both the correct colour and luminosity of an object; or deliberately messing with one of these values.
The author talks of a Monet painting (see below) in which the sun is actually darker (in value) than it should be. She claims this gives a special resonance to the painting. It is therefore an interesting idea to consider messing around making things the right colour but the wrong luminance – or vice versa – to see if any interesting effects can be achieved.
3) Different colours have different luminosities
Red and blue are always darker than green and yellow, which is the lightest colour.
4) Blue objects are lighter at night and darker during the day. Red objects are darker at night and lighter during the day.
If you’re going to paint a blue bowl full of red cherries at night, you must remember that at night you use your rods. The rods capture blue light better than red, so the cherries look darker than the bowl. Conversely, during the day, when you use your cones, the red cherries will be lighter than the darker bowl.
Moral of the story: value relationships change according to the light.
Chapter 4: About how the brain processes what the eye sees
1) VERY IMPORTANT: The eye is only interested in discontinuities in a picture.
Thus a solid region of uniform colour will not be scrutinised. But every single line will be. Also every gradation of colour/value. An art work is completely defined by its transitions.
This suggests that an artist should spend an inordinate amount of time on the transitions and be rather laissez-faire with regions of uniformity.
Also, if you put line discontinuities where there are none, you will attract the eye to regions of the art piece that should be ignored. This happens for example when shading is too choppy, going from dark to light.
Very controlled and subtle value transitions are thus needed when completing a portrait, for example, and rendering the skin tones. They must be subtle so that a) the eye can detect these transitions of light without b) confusing them for rigid changes of form or structure.
2) Local differences are more important than global differences.
First of all, when it comes to conveying colour or luminance with paint, it must be understood that artists have a severely limited set of pigments with which to represent the real world.
Suppose we have a painting with just a bright white sun on the right side, a blue sky of uniform colour and value, and some white clouds on the left side. Now, although the sun is way more luminant than the clouds, an artist only has basically one choice of white to use for both sun and clouds.
To portray the sun as brighter, it would be wise to paint the sky around it very dark. In contrast the sky around the clouds should be painted very light. This is despite the fact that in reality the sky is of a uniform darkness.
To make this all work, the light part of the sky should imperceptibly become darker as you paint across to the side of the sky where the sun is.
The point is that our visual systems are hopeless at registering the global change of the darkness of the sky. But they will hone in on the local differences between sun & sky or the clouds & sky.
Chapter 5: About Central and Peripheral Vision
1) The author suggests that the Mona Lisa’s expression seems to change from smiling to serious because her mouth moves from your peripheral vision to your central vision as you view the painting.
ABOVE: Mona Lisa as seen in peripheral vision (left) and direct gaze (right) and somewhere in between (middle).
As you move your gaze around a portrait, the mouth is at times in the peripheral vision and then at times is at the centre of the gaze. When it is centre of gaze we see all the details – and therefore see it as not smiling. However, as you look at other aspects of the face – the eyes, nose, hair etc – and see the mouth only in your peripheral vision, you then see only it’s larger ‘global’ characteristics.
The author contends that da Vinci, has made these ‘global’ characteristics such that they define a smile. Whilst when one looks at the mouth directly, these ‘global’ characteristics are ignored and the fine details – which show a mouth not smiling – are seen.
2) What is peripheral vision?
An interesting question is what actually is peripheral vision? I mean if you had to paint what you see out the corner of your eye could you do it? The author makes the point that it is not just the same as blurriness.
3) Impressionism is more realistic than traditional painting for highly active scenes.
The author contends that for a painting such as Poussin’s ‘The Rape of the Sabine Women’, there is a problem between the rigidity of the painting and the multiple scenes of rapid action that it depicts (not that it’s not a great artwork).
In contrast impressionistic paintings, where detail is left undefined and incomplete, provides the eye with sensory information similar to that it experiences when jerking around a high action scene.
Chapter 6: About Contrasts between Neighbouring Colours
1) It is important to use Opponent Colours because they most optimally trigger the receptive cells in the eye.
White & Black, Orange and Blue, Purple & Yellow/Green, and Green and Red, seem to be colour combinations that make things ‘pop’. For example if you’re painting an orange and then put in a blue background, you should find that the orange ‘pops’ i.e. seems to stand out.
2) The Colour of Shadows.
In any shadow, sunlight is blocked out. Does this mean the shadow will be black? No, it will have reflected light in it, from secondary sources of light in the scene. E.g. If the sky is blue, there should be blue light in the shadow.
Chapter 8: About Shading and Chiaroscuro
1) Real World Range of Luminosities Vs. Paint Range of Luminosities.
The range of luminosity in the real world is somewhere between a factor of 100 or 1000 going from lightest lights to darkest darks. E.g. consider the difference between a bright hot sun and the shaded interior of a house. But with paints, white is only 20 times more luminous than black.
Fortunately this is maybe not so relevant as once again, the eye works by a process of contrasts and comparisons.
However, could painting on transparent media – something similar to stained glass – get around this problem?
2) Matisse’s Fauvist artwork uses the correct luminance but the wrong colours.
Personally I’m not a fan of the work of Matisse but it’s an interesting idea. Especially when you consider that getting the correct luminance is way more important than getting the correct colour, according to how our visual systems work.
Chapter 9: About Depth Cues & Stereopsis
1) Seeing 3D objects with both eyes provides major depth cues. This process is known as stereopsis. It presents a great barrier to realism.
It’s a complicated business but I think that provided the viewer’s head is kept fixed when viewing the painting, in the same position the artist viewed the subject, it actually shouldn’t be a problem.
The issue is that viewers of art will inevitably move their heads from side to side; and by doing so they essentially shake off the realism of the artwork, when it fails to provide them with the depth cues they would get from a 3D object.
Ways round this would be to perhaps paint small, which might minimise the problem. Da Vinci suggested people should view artworks with one eye. In that spirit I would suggest keeping a viewer’s head in a 1984 style head clamp.
Actually if we’re talking about the issue of ‘how art should be presented and viewed’, why do artists never take advantage of the stereograph phenomena, in the way for example that View Masters did?
2) Blurriness & Impressionism can make a painting look more dimensional.
The author suggests that blurry artworks and Impressionistic paintings fail to provide the eye with stereoscopic depth cues that would indicate that the painting actually lacks dimension. Thus, contrary to intuition, blurry, loose and impressionistic artworks might actually look more real.
3) Repetitive patterns in a painting can induce a viewer to feel a sense of depth.
The explanation is complicated, but I think this idea lies behind the Magic Eye phenomena. I’m interested to know if it can be applied to painting.
Chapter 10: About Perception of Motion
1) Equiluminance can cause an illusion of motion.
Try reading a text, where the background is red say and the letters blue, BUT both have the same value or luminance. This confuses the brain and creates a shaky, jumpy sensation.
2) Illusions such as the McKay illusion can cause a profound sense of motion.
The question however is, can such illusions be easily and successfully incorporated into artwork?
What about the illusion seen here in Fall by Bridget Riley?
Chapter 11: About Colour Mixing & Colour Perception
1) Our perception of colour is coarse.
Colours can run outside their boundaries with little effect. Think about a ‘paint by numbers’ coloured in by a child who scribbles a lot. It can still look effective even if colours overshoot the boundary.
2) Colour is only really defined at its edges.
Again, the eye doesn’t take much interest in interiors of objects done in a uniform colour.
3) Mix two paint colours and the result will only reflect light that is reflected by BOTH the original colours.
Yellow paint and blue paint gives green paint because green is the only colour reflected by both yellow and blue.
Similarly, because blue and red have little in common, in terms of light they reflect, it can often happen that when they are mixed you will end up with a very dark and awful grey.
Chapter 12: About TV and Films
1) TV and Film work on very different principles.
Not directly related to art but interesting. Film works on the same principle as a flick book. The mechanism that makes TV work is incredibly complicated by comparison. Why? I don’t know.