The iconic three shade system of the PH series of lighting fixtures was created in 1925/1926 by Poul Henningsen for an exhibition in Paris. The designer was determined to produce glare free lighting that was directed where it was needed most while creating soft shadows. The three shade system creates an even distribution of light as each shade reduces the light equally due to their distance from the light source. This is the first lamp to have been created using the scientific model of the logarithmic spiral as a basis for light distribution. There have been approximately one thousand variations of the original lamp with several floor, table, wall, and pendant versions currently available.