Poul Henningsen unveiled his 3-shade design based on the logarithmic spiral in 1925 and the same system animates PH 3/2½ Wall, proving remarkably even and glare-free lighting outdoors. The fixture embodies the principle of reflection in its triple spun stainless steel shades that direct the majority of the light downwards and have a matte-white painted interior surface to soften and diffuse the illumination.