Last time on Learning to Look we considered direction of light. Light is instrumental in contributing to the mood of a painting so as well as deciding what direction the light will come from, the artist also has to decide what kind of light it will be.

Painted light can be soft and gentle or harsh and sharp. It can cast a glare or glow. Like all aspects of looking at a work of art, light doesn’t work in isolation but blends with colour, style and technique to create an overall effect.

Dim lighting subdues a painting, narrowing the range of tones. In this Winter Landscape (c. 1811) by the German Romantic landscape painter Caspar David Friedrich, there are neither highlights nor noticeable shadows.

In the foreground a crippled man sits against a rock with hands raised in prayer before a crucifix. He has discarded his crutches. Though snow and sky create soft sources of light, fog envelops the landscape and diffuses the light, leaving only subtle tonal variations from light to dark in the painting. The diffused lighting is an apt choice for a painting that explores the idea of hope for salvation through Christian faith. The scene is full of symbols, such as the rocks and evergreens as emblems of faith and the Gothic cathedral coming from the gloaming standing for the promise of life after death.

Coloured lighting creates a definite mood: it affects the painting as a whole just as a tinted filter suffuses a photograph. If the light is coloured, the shadows are too. In Pissarro’s picture of Apple Picking at Eragny-sur-Epte (1888) a sense of the midday sun fills the scene with golden light and creates a radiant and warm feeling.

Bright strong light creates sharp tonal contrasts with brilliant highlights and dark shadows and throws detail into sharper focus. This kind of lighting works best when it comes from an angled source to emphasise the play of opposite ends of the tonal range.

The Italian word chiaroscuro (meaning light-dark) is sometimes used to describe how artists distribute light and shade to depict form. In the Incredulity of St Thomas (1602-3) Caravaggio’s strong lighting creates dramatic tonal contrasts and focuses the eye on the most important part of the story, i.e. Thomas’s contact with Christ’s wounds. Caravaggio’s unflinching realism is heightened through the use of chiaroscuro.

Caravaggio has a sense of cinema about him in his use of light to orchestrate our looking at a scene. Another dramatic way to light a painting is to focus a beam of light on one area. As on a stage, this focusses your attention on the spot-lit section, which is thrown into dramatic relief by the surrounding deep shadow. This approach is used in this painting (1791) by Anne-Louis Girodet:

Here light symbolises the Roman moon goddess Diana and draws attention to the beautiful form and face of Endymion (with whom she fell in love and had 50 daughters…) sent to sleep for ever in return for perpetual youth.

Highlights are used by artists to suggest pinpricks of light. They can make a surface look shiny or show movements on water. Because highlights are the highest tones in a picture they catch the eye. In oil painting artists tend to work from dark to light and add highlights last.

Here is an Old Woman Cooking Eggs (1618) and Velazquez has made a humble earthenware pot sparkle with just a dash of bright white paint.