Sources of Natural Light; Sunlight
As we mentioned on our previous article to effectively use natural light, first we must try and understand its abilities. Sunlight can be defined as direct-beam light through clear or partially cloudy skies.
Partially cloudy skies are also partially clear. Clear sky and sunlight together act very differently from a diffuse overcast sky. In clear, sunny condition, sun is the brightest source of light, virtually a point source coherent, parallel rays producing sharp shadows.
The light intensity of sun varies with many factors such as latitude,solar altitude and atmospheric conditions. The solar illumination at sea level can exceed to can exceed 100,000 Lux perpendicular to the sun’s rays, the color temperature of sunlight changes also, from 1000 to 1800K at sunrise to approximately 5000K at noon. This is considerably lower than a clear blue sky at greater than 10000K.
Atmosfere of the clear blue sky filters and diffuses light, but provides low illumination. Near the sun the sky is bright, but majority of the blue sky provides less bright illumination than overcast skies. The allure of northern skylight for artists is due to its consistency of intensity and color temperature.
To find out more about Natural light, follow us on our next article “Sources of Natural Light; Reflected Light”.