Poul Henningsen designed this three-shade system during 1925/1926 and the PH Series from Louis Poulsen was born. Throughout his life, PH sought to create glare-free lighting; aiming to direct light where it was most needed, and creating soft shadows while using incandescent bulbs as a light source. Approximately one thousand models have been produced over the years and consisted of table, floor and wall lamps, as well as a number of pendants and chandeliers. Henningsen was the first person to pursue a scientific approach to light and use the logarithmic spiral as a basis. By using a design based on the logarithmic spiral, he achieved even distribution of light over the entire curve of the shade.