Luminous Surfaces Equal Ambient Luminescence
In 1952, Richard Kelly, considered the founder of modern lighting design, defined his "three elemental kinds of light effect", or layers of light, one of which he labelled "ambient luminescence".
Ambient luminescence refers to the comfortable background lighting of life. In its ideal form ambient luminescence from architectural lighting produces “shadowless illumination” and a sense of space in the same way nature’s luminous surface provides, in his words, “the uninterrupted light of a snowy morning in the open country."