Find a room lit fairly brightly by tungsten lamps. Measure the light level in the room with your camera’s meter.
Tungsten is orange, weaker and gives uneven lighting compared to daylight. This type of light tends to be the standard type of lighting found in houses and in large interiors used by the public.
Tungsten lights act in a similar way to sunlight in that they emit a continuous light (Freeman 2004, p. 13), therefore steadily exposing a photograph. They are incandescent, they shine by burning, and the brightness depends on how much the filament is heated. Tungsten lights have a distinctive yellow/orange glow.
It was whilst reading Freeman’s Light & Lighting that I found out about the inverse square law, which explains the science behind this project.
The Inverse Square Law: “the intensity of light radiating from a point source is inversely proportional to the square of the distance from the source”
The dphoto website offers a visual explanation to this principle, that the further an object is away from a light source the weaker the light. Twice as far from a light source means 4 times less light. The wattage of the bulb will also have an influence over this law. The brightness of a 60 watt tungsten bulb would be very weak at 5 feet from the light source, whereas an 800 watt tungsten halogen lamp would be brighter up to 20 feet away.