Richard Kelly is a 20th century American lighting designer who has been considered one of the pioneers of architectural lighting design. With a background in stage lighting, Kelly introduced a scenographic perspective for architectural lighting. His principles are self-evident with today's architects but during his career, they were groundbreaking as he broke the engineering dominant mindset found in the early 20th-century architecture.
In his college paper, essay "Light as an Integral Part of Architecture" (1952) he introduced his three principles of lighting design:
Focal Glow - "Focal glow is the follow spot on the modern stage. It is the pool of light at your favourite reading chair. It is the shaft of sunshine that warms the end of the valley. It is candlelight on the face, and a flashlight on a stair... Focal glow draws attention, pulls together diverse parts, sells merchandise, separates the important from the unimportant, helps people see.”
Ambient luminescence - "Ambient luminescence is the uninterrupted light of a snowy morning in the open country. It is foglight at sea in a small boat, it is twilight haze on a wide river where shore and water and sky are indistinguishable. It is in any art gallery with strip-lighted walls, translucent ceiling, and white floor. (...) Ambient light produces shadowless illumination. It minimizes form and bulk.”
Play of brilliants - "Play of brilliants is Times Square at night. It is the eighteenth-century ballroom of crystal chandeliers and many candle flames. It is sunlight on a fountain or a rippling brook. It is a cache of diamonds in an opened cave. It is the rose window of Chartres... Play of brilliants excites the optic nerves, and in turn stimulates the body and spirit, quickens the appetite, awakens curiosity, sharpens the wit...."