Light and shade in the landscape

Arnold Lowrey highlights some of the most common errors to be aware of when painting shadows

Light and shadow create two basic shape patterns within a painting. If they are done well and create interesting shapes, they will enhance your composition, but bad use of light and shadow can have a disastrous effect on any painting.

Form and cast shadows

There are two types of shadows: form shadows and cast shadows. Form shadows appear on the sides of objects that face away from the light, whereas cast shadows are produced by these objects cast onto adjacent objects, such as the ground or other buildings. The latter type change constantly in the sunlight due to the passage of the sun through the sky.

Cast shadows tend to be lighter and softer edged the further away they are from the object that is creating them. This is because the source light (the sky) and light bounce from nearby objects (adjacent walls, for example) lighten them.

Form shadows are nearly always joined to cast shadows on objects connected to the ground. An exception to this would be a cloud casting a shadow.

Direction of shadows

The direction of shadows is dependent on the light source, which in daylight is moving all the time. It is therefore essential to take a ‘snapshot’ of the shadows when you are drawing to ensure that all the shadows follow the same direction at one point in time.

Every art exhibition has paintings where the artist has forgotten this and the shadows painted in the morning are going in a different direction to the ones painted in the afternoon.

The small sketches above illustrate different light sources and the effect that they have on the subject.

The contour of the ground will also have an effect on the cast shadow, such as in the figure (right) which
shows a shadow on uneven ground that then crosses a road.

Tonal value of shadows

The tonal value of shadows depends on the time of day. Early morning shadows are long and dark (see, for example, the paintings of Rembrandt), while midday shadows are lighter because more light bounces into them.

Some artists work on the basis that an object in shadow is approximately 40 per cent darker in tone than the side that is in the light. In other words, assuming a grey scale from zero to nine where zero equals white and nine equals black, a white object with a value of zero will have shadows with a value of four in greyness.

However, this is not a golden rule and you should always paint what you feel is right and not stick to the rules, unless you are aiming specifically to produce an exaggerated effect.

Shadows are also affected by the quality of different sources of light; for example, spotlighting or floodlighting. Spotlighting, such as an early morning sunrise, will produce much sharper and darker edged shadows, while floodlighting, such as a sunny midday, will have lighter, softer shadows caused by the light reflecting or bouncing in from adjacent objects.

Light-toned shadows give a feeling of glare that might leave you reaching for your sunglasses. And it is also important to remember that cast shadows appear darker next to the lightest shapes and are also a little lighter in their centres. But the camera never sees this effect.

Size

The size or length of shadows depends on the position of the light source. Usually, the lower the sun is
in the sky, the longer the shadows that are cast. The angles made by the contours of the ground on
which they are cast will also have a bearing on this.

Colour

The colour of a shadow is generally a tone of grey but it also contains the complementary colour of the light source. So, for example, if the light source is yellowy (the sun), then the shadow will contain a hint of purple. By the same token, in a red light, the shadows will contain a hint of green.

Remember too that the centre of a shadow area is usually a touch lighter than the edges and it contains a hint of the light source colour. For instance, if a house situated in an orange field is lit by a yellow sun, the shadows would be purplish (the complement of yellow) with a shadow centre of orange from the light bounce of the sun. Try looking at various combinations of colours.

But don’t forget that rules are there to be broken and as an artist you can intensify the colours of shadows as much as you like. You only have to look at Van Gogh to see this technique being used.