Artist Paintings

Lore & Background

The use of natural light in architecture, called daylighting, first rose to professional importance during the Roman Empire. The Pantheon, rebuilt during the reign of emperor Hadrian (117 CE – 138 CE), employs an oculus to let in unobstructed but diffused light, much like a modern north-facing window or skylight. In painting, north light was an important feature in studios before the development of electric lights. Italian Renaissance painter Leon Battista Alberti alluded to the lack of dynamic range in paints in 1435, writing that 'no surface should be made so white that you cannot make it [...] whiter still'. Leonardo da Vinci first wrote about studio lighting in detail; by 1492 he had discovered the adaptation of the human pupil to darkness, noting that 'the eye perceives and recognises the objects with greater intensity [when] the pupil is more widely dilated'. He painted in a dimly lit studio and avoided harsh southern light, effects seen in later works such as the Mona Lisa. The use of specifically northern light became more common during the Dutch Golden Age with painters such as Rembrandt and Johannes Vermeer, as seen in Vermeer's The Milkmaid.

In Their Own Story

Because the sun passes to the south of most observers in the northern hemisphere, north light is the light coming from the sky, rather than directly from the sun. This is the reason for its diffused nature, as well as why it casts softer shadows than direct sunlight and remains more consistent in colour than light from the east or west. The colour of diffused daylight is 5500 - 6500K, meaning that north light is cooler (more blue tinted) than light from other directions. The main cause of this is Rayleigh scattering, first mathematically described by British physicist Lord Rayleigh in 1871. Earth's atmosphere contains large proportions of nitrogen and oxygen which, via Rayleigh scattering, scatter short wavelengths of electromagnetic radiation more efficiently than longer wavelengths. Thus, light scattered or diffused away from the main beam of sunlight appears cooler while direct light (especially during sunrise or sunset) appears warmer. North light is also less bright than direct sunlight, as only a portion of incoming white light is scattered. The brightness of north light can be between 10,000 and 30,000 lux, depending on location and season, while direct sunlight can be as bright as 100,000 lux.

Reader's Guide

In architecture, because the sun moves to the south of buildings in the Northern Hemisphere, the northern side of these buildings is always in the shade. For daylighting, this has certain implications: north-facing rooms can feel dark and cool, controlled by painting the room a bright colour such as red, yellow, and orange, finishing with wood, or using larger windows. North light does not change colour throughout the day, so whichever mood is achieved through the room's painted colour, it is likely to remain constant. As north light is more diffuse than direct sunlight, it poses less problems with glare, making it suitable for office spaces, home theatres or reading rooms. Infrequently used rooms such as laundries, hallways and bathrooms can be oriented north, freeing up south-facing floor plan space for rooms used more often. The latitude of a building changes the effect of north light: near the equator, the only difference between north and south light may be seasonal; in temperate regions, the implications apply year-round; in polar areas they may be even more extreme. For example, Anchorage in Alaska receives only five hours of sunlight at winter solstice, with the sun rising only 5.5 degrees above the horizon, making north-facing windows too dark to be of any use during winter. Houses that rely on sunlight, wind and insulation to regulate their temperature are known as passive houses. Because of its lower brightness and lower amount of infrared radiation, north light transmits less warmth to buildings than direct sunlight does. This makes large north-facing windows better suited for passive houses in warm, tropical climates, as it allows living areas to receive ample sunlight without overheating the building. Artists without access to north facing windows have developed alternative solutions: diffusing direct sunlight by adding opaque covers such as sheets, blinds, or tracing or baking paper; painting early or late in the day; or using artificial lighting such as a daylight lamp or continuous, daylight-balanced studio light with softboxes. However, due to the inverse square law, light falling on an object close to its source will decrease in brightness over a shorter distance than light falling on an object further away from its source, meaning any artificial lighting must be fairly powerful and positioned a long distance away from the subject to accurately imitate north light. Photographers use north light for similar reasons as painters but have access to electric lights as well. The use of softboxes and bouncing speedlights against umbrella-shaped diffusers strives to recreate the soft shadows that north light produces, popular in portrait photography. Since the early 20th century, photographers and filmmakers have used Rembrandt lighting to return some dramatic effect to diffused light, both in portraits and cinema. This entails a key light illuminating the subject (such as a north-facing window) and a reflector facing the other side of the subject. Like painters, photographers can modify south light or use artificial lighting as a replacement for north light if needed. They can also employ post production software such as Adobe Lightroom and Photoshop to correct exposure and temperature, and dedicated software such as Robin Myers Imaging EquaLight can adjust for lens and lighting falloff, especially useful for fine art photographers.

Did You Know?

• The colour of diffused daylight is 5500 - 6500K, making north light cooler (more blue tinted) than light from other directions.
• The brightness of north light can be between 10,000 and 30,000 lux, while direct sunlight can be as bright as 100,000 lux.
• Leonardo da Vinci first wrote about studio lighting in detail by 1492, noting that 'the eye perceives and recognises the objects with greater intensity [when] the pupil is more widely dilated'.
• The Pantheon, rebuilt during the reign of emperor Hadrian (117 CE – 138 CE), employs an oculus to let in unobstructed but diffused light, much like a modern north-facing window or skylight.
• A 2004 study found 3600K to be the preferred temperature for art appreciation, while a 2008 study by the Optical Society of America suggested 5100K as the optimal temperature.