Lime on a Teatowel – highlights and shadows

By learning the names and recognizing shadows and highlights help us tune in to observing them when painting in oils. A well lit subject can have at least 10 nuances of colour!

• When the light changes gradually from light to dark or dark to light it is diffused light.
  The midtone is the average colour or light.
• The core shadow is the darkest interior shadow often just beyond the terminator. It is the darkest shadow within the object.
• Cast shadows can be crisp on the edges like this one, but on a cloudy day may be diffused. Cast shadows often change in intensity as they get further away from the object.
• The occlusion shadow is the darkest shadow between the object and the cast shadow. It is where the object makes contact with the ground.
• The light area indicates the direction that the light comes from e.g. the right.
  The highlight is the brightest area of light and is often a small area. It is painted last in oils.
• The terminator (this sounds like sci-fi) is diffused on a curved surface and crisp on a planed surface. It is where the light changes from light to dark as the 3D plane changes. In realistic painting, this should be blended on a curve, but is crisp on a sharp change of plane e.g. a box .
• Reflected light reflects the colour of the ground – this shows on light or shiny objects. Here you can see a little white shape, reflecting the tea towel.
• If the light source is from the front, both edges will be darker and the centre of the object will be brighter.
• And lastly, if the light source is from the back, you will often find two cast shadows, one lighter than the other. Most of the object has a core shadow and the edges are lit. An extreme is when the object is a silhouette and looks two-dimensional.