With the increased focus on the environment and the energy crisis, revisiting and evaluating sources of natural light has gained new importance. It's worthwhile to keep in mind that humans still lived in relative comfort before the advent of electricity, as they took advantage of a range of natural light sources available.
The sun is the most common source of natural lighting and one of the most vital. Even the most well-decorated room, seems dreary without natural light. A sunny room seems naturally cheerful, without relying on light fixtures. The sun provides natural, innate warmth, dry clothes, lightens hair and help plants grow. According to Schneiderkreuznach.com, "The sun radiates at a color temperature of 5800 K ... As observers, we always have the impression that sunlight is yellow or gold. In reality, it is more like the flame from an electric welder." Regardless of its appearance, it is powerful and has a variety of uses and influence.
While many don't give the moon enough credit, it provides a subtle source of illumination. According to Schneiderkreuznach.com, "This light is reflected sunlight striking the moon's surface. It has a color temperature of approximately 4000 K and therefore has a warmer color tone than sunlight." Moonlight prevents the night sky from being completely pitch black.
Fire is another source of light that produces a glow as well as heat. Fire is a natural light source used in a variety of ways. Candlelight gives a room a soft luminance. A bonfire or burning logs in a fireplace provide heat as well as creating a focal point. Torches illuminated people's path in the outdoors at night.