This is the fourth in a series of posts looking at the Five Basic Skills of Drawing.
It could be argued that the perception of light and shadow is the most important skill in drawing and painting.
Often, when you look at a drawing that doesn’t quite look convincing, the problem is an error in the lightness or darkness (the value) of certain areas.
These errors can cause problems because when we look at an object in reality, we see the shape of it as described by the way the light falls upon it. If we draw this light incorrectly, then the shapes will look wrong.
If light is shining on a face from the right, then shadows are formed to the left in areas where the light is blocked. If we make these shadows too dark or too light, it changes the appearance of the surface, making the drawing appear inconsistent with reality.
Drawing accurate values (often referred to as shading) is the key to achieving a convincing three-dimensional illusion in your drawings.
Limitation of media
When we talk about accuracy of values in a drawing, it doesn’t mean that you have to draw the exact values that you see in reality.
In fact it’s almost impossible to do so, because no drawing or painting medium can represent the full range of values that we see in reality.
What we are really talking about is accurate value relationships.
What this means is that we need to focus on the relationships between the values, rather than the values themselves.
For example, if you’re drawing with an HB pencil, and trying to represent something which, in reality, is very dark, almost black. The pencil simply doesn’t allow you to draw such a dark value, so instead, we focus on the value relationships.
Use the darkest value you can get out of your pencil to represent the darkest dark of your subject. And let’s say the lightest light will be represented by the white of the paper (which again is not as light as the lightest light in reality).
Then, if you see a value in reality, which appears to be midway between the darkest dark and the lightest light, then you would draw that value as midway between the your dark pencil tone and the white paper.
All the values of your drawing will be scaled in this way, to keep the value relationships accurate.
By focusing on value relationships, you can draw or paint accurately in any medium, no matter how limited the value range.
Learning to see values
I spend a lot of time just doing value studies, where the only purpose of the drawing is to practice seeing value relationships. Here’s a value study I did as an assignment for Jason Seiler’s Schoolism class (affiliate link). The painting was done in Photoshop over the top of an original sketch by Jason.
The best technique for learning to see values and value relationships accurately is squinting.
By narrowing your eyes, you remove a lot of detail, allowing you to more easily see the values. When I’m blocking in values, I do most of it with my eyes squinted when looking at the subject (make sure you open your eyes when looking at your drawing though!)
As always, let me know in the comments below if you have any questions about the perception of light and shadow, and I will do my best to help.
Next time we’ll wrap up this series, with a look at skill number 5 - the perception of the whole or gestalt. Subscribe to updates below to make sure you don’t miss it.