"key light" meaning in English

{
  "forms": [
    {
      "form": "key lights",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "key light (plural key lights)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Film",
          "orig": "en:Film",
          "parents": [
            "Entertainment",
            "Mass media",
            "Culture",
            "Media",
            "Society",
            "Communication",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Photography",
          "orig": "en:Photography",
          "parents": [
            "Art",
            "Human activity",
            "Media",
            "Culture",
            "Human behaviour",
            "Communication",
            "Society",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Television",
          "orig": "en:Television",
          "parents": [
            "Broadcasting",
            "Mass media",
            "Media",
            "Telecommunications",
            "Culture",
            "Communication",
            "Technology",
            "Society",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2015, Don Presnell, Marty McGee, A Critical History of Television's The Twilight Zone, 1959-1964, page 57",
          "text": "Age lines were drawn on McCarthy's face in red makeup, and when key lights with red filters were used, the lines were not visible.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "The most important light, used to highlight the form and dimension of the subject."
      ],
      "id": "en-key_light-en-noun-LEBcznr7",
      "links": [
        [
          "photography",
          "photography"
        ],
        [
          "film",
          "film#Noun"
        ],
        [
          "television",
          "television"
        ],
        [
          "form",
          "form"
        ],
        [
          "dimension",
          "dimension"
        ],
        [
          "subject",
          "subject"
        ]
      ],
      "raw_glosses": [
        "(photography, film, television) The most important light, used to highlight the form and dimension of the subject."
      ],
      "synonyms": [
        {
          "word": "keylight"
        }
      ],
      "topics": [
        "arts",
        "broadcasting",
        "film",
        "hobbies",
        "lifestyle",
        "media",
        "photography",
        "television"
      ],
      "wikipedia": [
        "key light"
      ]
    }
  ],
  "word": "key light"
}

{
  "forms": [
    {
      "form": "key lights",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "key light (plural key lights)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Quotation templates to be cleaned",
        "en:Film",
        "en:Photography",
        "en:Television"
      ],
      "examples": [
        {
          "ref": "2015, Don Presnell, Marty McGee, A Critical History of Television's The Twilight Zone, 1959-1964, page 57",
          "text": "Age lines were drawn on McCarthy's face in red makeup, and when key lights with red filters were used, the lines were not visible.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "The most important light, used to highlight the form and dimension of the subject."
      ],
      "links": [
        [
          "photography",
          "photography"
        ],
        [
          "film",
          "film#Noun"
        ],
        [
          "television",
          "television"
        ],
        [
          "form",
          "form"
        ],
        [
          "dimension",
          "dimension"
        ],
        [
          "subject",
          "subject"
        ]
      ],
      "raw_glosses": [
        "(photography, film, television) The most important light, used to highlight the form and dimension of the subject."
      ],
      "topics": [
        "arts",
        "broadcasting",
        "film",
        "hobbies",
        "lifestyle",
        "media",
        "photography",
        "television"
      ],
      "wikipedia": [
        "key light"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "keylight"
    }
  ],
  "word": "key light"
}