Map Light and Shadow on One Simple Form

A shaded side of an object and the shadow it casts on a table are different parts of a drawing. Separating them makes a lighting plan easier to follow. This exercise uses one ordinary object, a fixed viewpoint and a small number of light and dark values. The result is a labeled observation map you can consult before making color decisions.

The Getty's value-to-form worksheet explains how light and dark values can suggest three-dimensional form and distinguishes a cast shadow from shading on the object. Sun Valley Museum of Art's shadow lesson also emphasizes observing and recording actual shadows. The exercise here uses an original tabletop comparison.

Choose a readable setup

Gather drawing paper and a pencil, or three existing colored pencils that you can distinguish as light, middle and dark. Use a plain, non-fragile object with a simple form. A matte cup or a small box is easier to inspect than a collection of shiny objects. Place it on a stable, uncluttered surface.

Choose existing light that produces a shadow you can see. If using an ordinary adjustable lamp, operate it as designed; no special lighting equipment is required. Keep the object and your viewing position fixed. If several lights create confusing shadows, choose a simpler setup or use your own clear photograph instead.

For help reducing the number of objects and deciding the viewpoint, use the tabletop still-life guide. Keep this exercise to one form so the observation remains manageable.

Make a light-direction map

1. Record the light source. Sketch a small arrow beside the drawing to show where the main light comes from relative to the object. This arrow is a note, not part of the finished picture.
2. Locate the main areas. Look for a relatively light area on the object, a darker area and any useful middle region. Locate the cast shadow on the supporting surface separately. Do not invent a middle band if the object presents only two clear values.
3. Draw the broad shapes. Sketch the object's outer shape and the cast shadow. Add only the major divisions you observed. Leave tiny reflections and surface patterns aside for this study.
4. Assign values. Make a small light, middle and dark key in the margin. Use those values to simplify what you see. Label a shaded area “on object” and the cast shadow “on surface” so the two roles stay clear.

The divisions are a planning approximation. A rounded form may change gradually rather than having a firm line between each value. A flat-sided box may show more abrupt changes. Record that difference instead of making every object use the same pattern.

Change one thing and compare

If practical, change the direction of the movable light while keeping the object and viewpoint in place. Make a second small map beside the first. Alternatively, compare two of your own photographs taken from the same viewpoint under different light directions. Note any other changed conditions so you do not attribute every difference to the light.

Use this record: “Light came from ___; the darkest area on the object was ___; the cast shadow extended toward ___; after the change, ___ moved or changed shape.” For example, a cup may retain the same outline while a lit area shifts and its cast shadow extends in another direction.

Review the observation

Check that the main lit area and cast shadow make sense together in the setup you actually observed. Then check whether the shadow's contact with the object is visible in your drawing. If a shadow edge is unclear, record uncertainty instead of inventing a sharp boundary.

Choose one map for a later painting. The contrast guide helps separate neighboring shapes, while color testing helps assess the materials you actually intend to use. This observation does not prescribe a shadow color or a paint-mixing formula.

Must I include every dark patch?

No. Keep the large divisions that explain the form and its relationship to the surface. Add a small patch only when its role is clear and useful to your chosen painting.