PH 5-4½ Pendant Light by Louis Poulsen

Poul Henningsen designed the three-shade system as early as 1925–1926. The first lamps to incorporate this system were designed for an exhibition in Paris. His collaboration with Louis Poulsen continued until his death in 1967. Throughout his life, PH strove to create glare-free light, direct light where it was most needed, and produce soft shadows—using incandescent bulbs as the light source. The four-shade system was introduced in 1931 to create a lamp that could be mounted high on the ceiling and serve as an alternative to the chandeliers common at the time. The PH four-shade lamp was designed to increase the amount of light emitted horizontally, thereby illuminating walls and shelves more effectively than was possible with conventional three-shade lamps. In the 1940s, it was removed from Louis Poulsen’s standard lineup, but in 1979 it was redesigned by the two Danish architects Sophus Frandsen and Ebbe Christensen for the Charlottenborg Exhibition Building in Copenhagen—albeit in a larger version: PH 6½/6. To solve the recurring problem of glare, the two architects decided to add a small blue shade to the design. They also introduced a new version with a more matte, white-lacquered shade to achieve a more even, pleasant light—ideal for museums and exhibition spaces or as general lighting in rooms with high ceilings. A smaller version, the 5/4½, was designed in 1984 for the concert hall in Aarhus.