"Petzval lens" meaning in English

{
  "etymology_text": "Developed in 1840 by Joseph Petzval.",
  "forms": [
    {
      "form": "Petzval lenses",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Petzval lens (plural Petzval 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": "English entries with language name categories using raw markup",
          "parents": [
            "Entries with language name categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with topic categories using raw markup",
          "parents": [
            "Entries with topic categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
          ],
          "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"
        }
      ],
      "glosses": [
        "A photographic lens consisting of two doublet lenses with an aperture stop in between."
      ],
      "id": "en-Petzval_lens-en-noun-wpGRkIYH",
      "links": [
        [
          "photographic",
          "photographic"
        ],
        [
          "lens",
          "lens"
        ]
      ],
      "raw_glosses": [
        "(historical) A photographic lens consisting of two doublet lenses with an aperture stop in between."
      ],
      "related": [
        {
          "word": "Petzval condition"
        },
        {
          "word": "Petzval sum"
        }
      ],
      "tags": [
        "historical"
      ]
    }
  ],
  "word": "Petzval lens"
}

{
  "etymology_text": "Developed in 1840 by Joseph Petzval.",
  "forms": [
    {
      "form": "Petzval lenses",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Petzval lens (plural Petzval lenses)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "Petzval condition"
    },
    {
      "word": "Petzval sum"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English entries with language name categories using raw markup",
        "English entries with topic categories using raw markup",
        "English eponyms",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with historical senses",
        "English terms with non-redundant non-automated sortkeys",
        "en:Photography"
      ],
      "glosses": [
        "A photographic lens consisting of two doublet lenses with an aperture stop in between."
      ],
      "links": [
        [
          "photographic",
          "photographic"
        ],
        [
          "lens",
          "lens"
        ]
      ],
      "raw_glosses": [
        "(historical) A photographic lens consisting of two doublet lenses with an aperture stop in between."
      ],
      "tags": [
        "historical"
      ]
    }
  ],
  "word": "Petzval lens"
}