How a Little Known Experiment with Chickens Can Help Artists Master Values

On November 3rd, 1933 the Nazi party, recently come to power, demanded that all professors begin their lectures with the Nazi salute.

Wolfgang Köhler, a professor and director of the Psychological Institute at the University of Berlin, refused.

Then he went one step further, and wrote an article openly criticising the Nazi party. It was the last official article to do so. He found it expedient to leave Germany for the United States not long afterwards.

Kohler contributed to some landmark work on a new, holistic approach to psychology called Gestalt theory. What’s most interesting to us about Köhler is an experiment he did with chickens in order to learn more about the nature of vision.

It’s all relative

Köhler took two pieces of paper, one dark and one light, and trained the chickens to expect their dinner on the lighter of the two. He then replaced the darker piece of paper with one which was now lighter than the one the chickens were used to finding their feed on, which he left the same.

Instead of going back to the same piece of paper that they’d been happily pecking away at, the chickens went to the new, lighter piece of paper and waited to be fed. So it wasn’t the exact lightness of the paper that mattered to them, they just knew to look for their dinner on the lighter one of the two. So they went to the wrong one.

They saw value in terms of relationships. So do we. Which is handy, because without that way of seeing value, we’d be unable to paint anything realistically.

We see with our brains

We think of seeing as something we do with our eyes, as a physical ability. In fact, it’s much more complicated. What we think of as what we see is actually a construct we create in our brains from a combination of a visual impression and our previous experience, through which we infer things about the scene like the direction and strength of the light, the distance of objects from us and from each other, and their size.

Seeing is something we do with our brains. Seeing is psychological. Without the active part our brains take in constructing a meaningful image for us, we’d just have a swirl of sensory information that would mean nothing at all. We’d bump into things all the time. And we wouldn’t be able to create realistic art.

So getting values right isn’t about replicating what you see. The next time you hear someone say “paint what you see, not what you know” be careful. The advice itself is sound. But putting it into practice is a lot more complicated than it sounds.

In fact what we see and what we know are an indivisible whole. What we see is a result of what we know, and understanding that can help us get our values more right. Ignoring it can leave us sitting on the wrong piece of paper, waiting for our dinner and wondering why our paintings don’t look right.

Here’s an example. In the image below, the white square in the centre of each face is exactly the same value: white. But they don’t look the same. Because we’re making inferences about the value relative to the context. We know the white square on the shadow side of the cube is in shadow, so we know it should be darker. The only sense our brains can make of it appearing lighter is if it’s glowing – actually emitting light. So that’s what it looks like to us.

It looks significantly lighter than the corresponding white square in the centre of the other two sides of the cubes. Our brains have constructed a version of what we see that makes sense to us.

What this means for us artists is that if we try to paint what we see, what we know will get in our way whether we want it to or not. You can’t just switch it off. If I asked you to copy that cube in paint, and to paint what you see, you’d be trying to paint the white square in the middle of the shadow side of the cube lighter than the corresponding one on the top – even though they’re exactly the same. Of course you would, because that’s what you see. It’s inextricably linked with what you know.

You’d mess up the value relationships and you wouldn’t get your dinner.

Why values are the key to realism

We have to deal with this because values show light, and light shows form. Form creates depth and the illusion of reality.

To demonstrate this, let’s take a painting, and take out the colour information and see if the realism holds up.

Here’s a painting of an old iron on a cloth I did a little while back:

Let’s see it again the hue and chroma information removed, so we’re just seeing the values:

Still works, right? In fact, none of the feeling of reality, of depth has been lost.

Now, there are times when hue and chroma can convey quite a bit in paintings, but that happens less often than you might think. So it follows that creating a higher degree of realism in your work – painting something that looks more real – means mastering values more than anything else.

Mastering values

Given the above, it would very handy if we could find a way to see values more reliably, especially when we’re learning. I’ve found that the best way to do this is to remove the context information. You can do that quite simply with a small piece of card with a hole in the middle. I call it a colour isolator.

The really useful thing about this little tool is that you can use it to isolate local values as well as perceived values. The first, you can do reliably. The second needs a bit more care in its use.

Here’s a few ideas for value exercises that will help you get a better handle on things:

1. Build sensitivity to value by practising matching local values

This will stretch your ability to judge values and your ability to replicate them at the same time. It’s such a simple exercise, but it’s incredibly powerful, if you do it enough.

You can do it with pencil, charcoal or paint. All you need to do is to choose a value you want to match (preferably a flat surface) and lay your colour isolator on it. That gives you a small, isolated patch of value to try to match.

Then draw out a small square on a piece of sketch pad paper, and try match the value you see, with the two apart. This is important because it’s the guessing, then the feedback that will help build your sensitivity to value.Once you’ve filled your little square with your guess at the value, place it over the colour isolator and see how you did. This is your feedback.

In this pic, you can see that it took me three goes to close to this one, my first guesses were much too light:

2. Remove the context

Do a simple still life painting of a medium value cube. Use the colour isolator to judge small areas of value. Be careful to ensure that you always hold the isolator at the same angle to your subject. You can use the isolator to override the context information and judge the values in isolation:

3. Practise your value relationships

Paint more little value studies of simple still life subjects, of different local values. Start by painting a black, a white and a medium grey cube individually, then paint all three together.

For this exercise, you won’t be able to match the full range of values that you see in the subject. It’s the relationships between the values that matters, not the exact values.

A great further step for this exercise is to place a cube, a sphere and a real world object of the same value in a shadow box and do a value study of them:

In this exercise, the cube is a simplified version of the sphere, which is a simplified version of the lemon. So by painting the cube first, using your colour isolator to carefully judge the values, you can get a good idea of the value range you’ll need for the sphere and the lemon.

Here’s a shot of the set up for this exercise:

There are two little value scales with three values each. With one placed on the painting surface, and one on the subject, you can make sure you have enough light on your painting surface to be able to reach the lighter end of the values in the subject. If you don’t do this, you may find yourself painting the lightest value you can in your study, white, and it still not be light enough to visually match the lightest values in the subject. In practice, I find it helps enormously to make sure you can visually get close to the lights in an exercise like this.

What we see is what we know

With experience and practice, we learn to override what we know and so get closer to what we see. Although actually, I think a more correct explanation may be that we add additional, art specific knowledge to what we already have.  So when we’re looking at a patch of white in shadow, we know to compensate and paint it darker than an untrained person would guess. I believe most accomplished painters do this automatically, and without knowing that they’re doing it. It’s a skill learned through repeated trial and error.

I also think that we can curtail some of that process of trial and error by getting closer to seeing value accurately and minimising the margin of error. That’s what the isolator does.

But it’s certainly not painting by numbers. Many times, as with the three cubes exercise, it will simply show you the limitations of the value range of paint. It will show you the values you can’t match. But that information alone is hugely valuable, since you’ll already know that you have to compensate for it. Instead of hunting and pecking (on the wrong piece of paper, like those unfortunate chickens) you’ll be in a position to make decisions about how to translate what you see into paint more effectively.

You can get better at values through just doing a lot of painting. That’s what most people do. Or you can get better at values through some very focused practice, working only on value for a while. The latter may be less fun, but I’d argue that it is also a lot less frustrating in the long run, because it will get you there more quickly and more reliably. And given the importance of value to creating realism, the effort is justified.

Free webinar

I demonstrated some of these exercises in a free webinar called Mastering Values. Whilst the webinars I do are intended as live events that people can get involved in and ask questions live, here’s a recording of the event. It was a lot of fun:

Despite his contributions to psychology, Wolfgang Köhler’s best known legacy is the phrase “The whole is more than the sum of its parts”. Although, he must turn in his grave every time someone says it, because his actual phrase was, “The whole is different than the sum of its parts”. It’s a central tenet of gestalt theory.

In a sense, when we build up a picture using the isolator as I’ve shown in the exercises above – or indeed, even when we do it through through experience and practice – we translate and combine the values we see into something new, something different that the sum of all those patches of value: an illusion of reality on a two dimensional surface.

The better we understand value, the very real limitations  of our materials and how we can overcome them, the more convincing our illusions will be and the more light, form and depth our pictures will have.

The first step is understanding that value, like so many things in painting, is about relationships, not absolutes. As long as we remember that, we won’t find ourselves sitting on the wrong piece of paper, wondering where our dinner is.

Best wishes and thanks for reading,

Paul