Shadow blister effect

{
  "id": "MLC-T-IND-005188",
  "term": "Shadow blister effect",
  "field": "Industrial and trades",
  "definition": "A visual effect in which the shadow of one object bulges toward the shadow of a second object as the two shadows approach each other, so that they appear to join before the objects themselves touch. It occurs when the light source is not a point, because the nearer object blocks part of the light that was illuminating the soft outer edge of the farther object's shadow, enlarging that shadow's darkest region until the two meet.",
  "subject": "Optics and imaging",
  "translations": {
    "de": "Schattenquellungseffekt",
    "es": "efecto de ampolla de sombra",
    "fr": "effet de bulle d'ombre"
  },
  "url": "https://mlchart.com/terminology/industrial/shadow-blister-effect/"
}