There are many important ingredients that go into the creation of a successful drawing. The subject, the medium, and the skill of the artist are all important. But perhaps the most important factor is the light that is captured in the drawing.
Clearly, we see objects because of the presence of light. Light reflects off of objects and sends information back to our mind telling us what we are seeing. The manner in which light reflects and behaves on objects is crucial to how we perceive those objects.
For the artist wanting to create the illusion of what is observed in a drawing, capturing the light becomes of upmost importance. Since light is how we see, it only makes sense that understanding the light is where we should begin. Drawing is about seeing, and light is how we see. When you consider this, it becomes clear just how important light should be in our drawings.
How to Create the Illusion of Light in a Drawing
The illusion of light in a drawing rests on the use of value. The positioning of values within a drawing is what informs the viewer of the light within the scene. Its use is critically important to the success of the image. Before we go into the arrangement of values on an object in a drawing, let's first review the concept of value.
What is Value?
Value is one of the seven elements of art - many consider it to be the most important one. Value is the darkness or lightness of a color. It is typically measured using a tool called a value scale.
Values on the value scale have specific names. Lighter values are referred to as tints while darker values are called shades.
When working with color, tints are created by adding pure white to a color and shades are created by adding pure black to the color. (Intensity, although related to value, is slightly different. Intensity of color is adjusted by adding gray to a color, instead of pure black or white.)
How Light Manifests on Objects
We see light and understand the form of objects based on the location of values on the object. These areas of values have specific names. Areas where light is directly hitting the object are called highlights. Highlights are usually indicated in a drawing using the tints of a color. The location of the highlights on a object help to understand the location of the originating light in the drawing.
Midtones are areas of middle value on the drawn object. Often, midtones are the actual hue (color) of the object.
Core shadow is the area on an object where less light is hitting the object. Generally speaking, these areas will exist on the object opposite from the light source. Core shadow is indicated by using the shades (darker values) of the color.
Reflected highlight, most noticeable on rounded objects, is light that is reflected from surrounding objects within a scene back on to the object. This reflected light may result from the surface that the objects are resting or from objects that are in close proximity. For colored drawings, a bit of the color of the surrounding object may be including in the reflected highlight.
Cast shadows are areas where light is blocked because of objects. Light is prevented from reaching these areas. These locations are indicated by darker values.
Here's a look at these areas of value...
The Light Source
The arrangement of theses areas of value all contribute to the illusion of a light source in a scene. The light source is the area(s) where light is originating. There are usually several light sources within a drawing and each should be considered. The location, strength, and color of the light source affects the values and location of values that are needed to create the illusion of the scene. (Video 5 in The Secrets to Drawing Video Course takes a look at how value can be handled when multiple light sources are at play.)
Keeping the light source consistent is important as well. For multiple objects within a scene, the highlights and core shadows must be in consistent their locations for the illusion of light to make sense.
Understanding how to create the illusion of a light source is clearly an important skill for any artist. Practice locating the areas of observed value on objects and be sure to include them in your drawings.