Easy on the eyes. Poul Henningsen sought to create glare-free lighting throughout his career as a designer, and for that we're grateful. This three-shade system was developed in 1925-1926 as entry in design expo in Paris, and it looks a lot simpler than it is. His aim was to direct light where it was most needed, to creating soft shadows while using incandescent bulbs as a light source (sucks to be American, we'll have to settle for LEDs, boo hiss). 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. This even light distribution, together with the diffuse reflection through the glass, made it possible to control glare and shadow. He really was on a mission. 

The PH 2/1 Pendant is a member of Henningsen's three-shade family and is one of 19 versions available today. The PH light model numbers refer to the shade size. Each top shade had a corresponding set of middle and lower shades. In the pure models, such as the 2/2, the top shade has a size of about 20 cm, with corresponding lower shades. The PH 2/1 Pendant consists of an approximately 20 cm top shade, but uses lower shades from the 1/1 model. 

The fixture design is based on the principle of a reflective three-shade system, which directs the majority of the light downwards. The shades are made of hand-blown, opal, three-layer glass, which is glossy on top and sandblasted matte on the underside, giving a soft and uniform light distribution.