"pancake lens" meaning in English

{
  "forms": [
    {
      "form": "pancake lenses",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "pancake lens (plural pancake lenses)",
      "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": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Optics",
          "orig": "en:Optics",
          "parents": [
            "Physics",
            "Sciences",
            "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"
        }
      ],
      "examples": [
        {
          "ref": "2015, Rico Pfirstinger, The Fujifilm X-T10 […] , Rocky Nook, →ISBN:",
          "text": "A particularly fitting choice is the small and flexible XF27mmF2.8 pancake lens. With it, the camera fits in the pocket of almost every coat or jacket.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A type of flat lens design."
      ],
      "id": "en-pancake_lens-en-noun-nkCEKPkW",
      "links": [
        [
          "photography",
          "photography"
        ],
        [
          "optics",
          "optics"
        ],
        [
          "lens",
          "lens"
        ]
      ],
      "raw_glosses": [
        "(photography, optics, informal) A type of flat lens design."
      ],
      "tags": [
        "informal"
      ],
      "topics": [
        "arts",
        "engineering",
        "hobbies",
        "lifestyle",
        "natural-sciences",
        "optics",
        "photography",
        "physical-sciences",
        "physics"
      ]
    }
  ],
  "word": "pancake lens"
}

{
  "forms": [
    {
      "form": "pancake lenses",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "pancake lens (plural pancake lenses)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English informal terms",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Optics",
        "en:Photography"
      ],
      "examples": [
        {
          "ref": "2015, Rico Pfirstinger, The Fujifilm X-T10 […] , Rocky Nook, →ISBN:",
          "text": "A particularly fitting choice is the small and flexible XF27mmF2.8 pancake lens. With it, the camera fits in the pocket of almost every coat or jacket.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A type of flat lens design."
      ],
      "links": [
        [
          "photography",
          "photography"
        ],
        [
          "optics",
          "optics"
        ],
        [
          "lens",
          "lens"
        ]
      ],
      "raw_glosses": [
        "(photography, optics, informal) A type of flat lens design."
      ],
      "tags": [
        "informal"
      ],
      "topics": [
        "arts",
        "engineering",
        "hobbies",
        "lifestyle",
        "natural-sciences",
        "optics",
        "photography",
        "physical-sciences",
        "physics"
      ]
    }
  ],
  "word": "pancake lens"
}