Halation

Part of speech: noun

Pronunciation: /həˈleɪʃən/

Definitions

1. An optical occurrence where excessive light diffusion creates a glowing edge around subjects in images leads to a softening effect
2. A light-induced phenomenon that manifests as a blurred brightness surrounding an object in visual media, often resulting in a halo appearance
3. An effect in photography where intense light creates a soft glow around objects, resulting in a blurred outline that enhances visual impact

Etymology: Halation is a photographic term, and its story is a matter of how a familiar word was reused. The "halo" in it comes from Ancient Greek "hálōs", which meant a threshing floor or a circle of light around the sun or moon, and passed into Latin as "halōs" before reaching English. The Greek and Latin sense of a luminous ring is still visible in the modern meaning, which describes a glow spreading outward from a bright source. The ending "-ation" is an ordinary suffix that English inherited through Old French from Latin "-ātiō", where it formed nouns of action or result. Adding it to "halo" produced a noun for the process or effect of haloing. Its meaning is therefore less about a ring of light in the sky than about the blurred fringe that appears when light is overexposed or reflected inside a camera or film.

Synonyms: glow, radiance, illumination