Bokeh

The quality of the out-of-focus light in an image. The background rendered as feeling rather than fact.

Bokeh is the personality of a lens's blur: how out-of-focus points of light render, discs or ovals or jittery rings, smooth or nervous falloff. Two lenses at the same settings defocus the same street into different moods; the background becomes texture with a temperament.

Feeling rather than fact is its narrative function, the world softened into atmosphere so the subject owns the plane of truth, city lights melting into warm coins behind a face. The craft is intentionality: bokeh as composed negative space, not as accident. Its shapes are the lens's signature; anamorphic ovals alone can date and place an image.