Mount adapter field reference¶

This page is a reference for the fields in canonical mount adapter records and in each product entry in the distribution data. You do not need to read it from beginning to end; use the field names to find the sections you need.

Every canonical mount adapter record uses the same structure. Because the structure does not branch by product type, these records have neither a productType field nor a product-type block.

The JSON shown on this page contains only the parts of actual canonical records needed for each explanation. The examples are not complete records. Some examples also show only part of an array. See the JSON Schema reference for each field's type, whether it is required, and its allowed values.

The main examples use the Mount Adapter FTZ II. The Magic Shift Converter (MSC) provides examples of multiple mount configurations, conversion optics, and additional mechanisms. Fields for lenses and related optical products are documented in the field reference for lenses and related optical products.

Identity and publication information (identity, lifecycle, and officialProductPages)¶

The Mount Adapter FTZ II demonstrates how identity information, the product release announcement date, and official product pages are recorded.

Source: data/records/adapters/nikon/mount-adapter-ftz-ii.json

{
  "id": "mount-adapter-ftz-ii",
  "identity": {
    "manufacturerId": "nikon",
    "brandId": "nikon",
    "productName": "Mount Adapter FTZ II",
    "modelNumberOptions": null,
    "alternateNames": [
      {
        "name": "マウントアダプター FTZ II",
        "region": "JP",
        "language": "ja"
      }
    ],
    "variants": null
  },
  "lifecycle": {
    "announcementDate": "2021-10-28",
    "officialDesignations": []
  },
  "officialProductPages": [
    {
      "url": "https://nij.nikon.com/products/lineup/accessory/body/ftz_2/index.html",
      "pageFamilies": [
        "nikon-imaging-japan"
      ],
      "region": "JP",
      "language": "ja",
      "publisher": {
        "type": "manufacturer-or-brand",
        "name": "Nikon"
      }
    }
  ]
}

identity.manufacturerId records the manufacturing entity ID, while identity.brandId records the ID of the brand displayed on the product. In this example, both IDs are nikon, whose display name is Nikon. In a distribution JSON, display names are available from the root referenceData object. The English official product name is stored in identity.productName, and the official Japanese name is stored in identity.alternateNames.

lifecycle.announcementDate is the official product release announcement date. A development-announcement date is not used as a substitute. An empty lifecycle.officialDesignations array means that no official designation was confirmed; it does not mean that the product is currently sold, in stock, or available. The removal of an official product page alone is not treated as proof that sales have ended. See URLs and sources for the distinction between official product pages and other sources used in research.

Mount configurations (mountConfigurations)¶

mountConfigurations records pairs of the lens-side source mount and the camera-side destination mount.

{
  "mountConfigurations": [
    {
      "lensSideMountSystemId": "nikon-f",
      "cameraSideMountSystemId": "nikon-z",
      "lensRetention": null,
      "lensRearProtrusionLimits": null
    }
  ]
}

{
  "identity": {
    "variants": [
      {
        "variantId": "canon-ef-nikon-z",
        "name": "Canon EF to Nikon Z",
        "modelNumberOptions": null
      },
      {
        "variantId": "nikon-f-nikon-z",
        "name": "Nikon F to Nikon Z",
        "modelNumberOptions": null
      }
    ]
  },
  "mountConfigurations": [
    {
      "lensSideMountSystemId": "canon-ef",
      "cameraSideMountSystemId": "nikon-z",
      "variantId": "canon-ef-nikon-z",
      "lensRetention": null,
      "lensRearProtrusionLimits": null
    },
    {
      "lensSideMountSystemId": "nikon-f",
      "cameraSideMountSystemId": "nikon-z",
      "variantId": "nikon-f-nikon-z",
      "lensRetention": null,
      "lensRearProtrusionLimits": null
    }
  ]
}

See the data model for the relationship between mount-system IDs and the registry.

Electronic functions and connection services (electronics, electronicServices)¶

electronics records whether electronic contacts are present and which electronic functions are available through the adapter.

The Mount Adapter FTZ II demonstrates how electronic functions are recorded.

Source: data/records/adapters/nikon/mount-adapter-ftz-ii.json

{
  "electronics": {
    "electronicContacts": true,
    "autofocus": true,
    "cameraControlledAperture": true,
    "lensStabilizationCommunication": true,
    "manualFocusAssistance": true,
    "metadataTransmission": {
      "present": true,
      "standards": [
        "exif"
      ]
    },
    "lensPowerTransmission": null,
    "recordingTriggerTransmission": null
  },
  "electronicServices": null
}

true means that support was confirmed, while false means that lack of support was confirmed. metadataTransmission.standards is null when transmission is confirmed but its standard is not identified. A field-level null, such as lensPowerTransmission: null, means that accepted published evidence does not establish support for that function. When the entire electronics value is null, no electronic-function information could be confirmed. electronicServices is separate from functions carried through lens contacts, so it can describe firmware updates through USB or a dock. See value states for how these states differ.

Conversion optics and additional mechanisms (conversionOptics, mechanisms)¶

conversionOptics records whether conversion optics are present, their effect on focal length and maximum aperture, their optical construction, and properties such as the supported image circle. mechanisms records each additional mechanism as a typed object. Nominal shift, tilt, and rotation amounts are nested in the corresponding mechanism's movements field.

{
  "conversionOptics": {
    "present": false
  },
  "mechanisms": []
}

{
  "conversionOptics": {
    "present": true,
    "focalLengthMultiplier": 1.4,
    "apertureChange": {
      "direction": "darker",
      "stops": 1,
      "relation": "exact"
    },
    "opticalConstruction": {
      "groups": 4,
      "elements": 5
    },
    "specialElements": null,
    "coatings": null,
    "supportedImageCircleDiameterMm": null,
    "maximumSupportedAperture": null
  },
  "mechanisms": [
    {
      "type": "shift",
      "conditions": {},
      "movements": {
        "shiftMeasurements": [
          {
            "maximumFromNeutralMm": 10,
            "totalRangeMm": null,
            "directionality": null,
            "conditions": {}
          }
        ]
      }
    },
    {
      "type": "rotation",
      "movements": {
        "rotationMeasurements": [
          {
            "scope": "movement-assembly",
            "maximumFromNeutralDegrees": null,
            "totalRangeDegrees": 360,
            "directionality": null,
            "conditions": {}
          }
        ]
      },
      "conditions": {}
    }
  ]
}

apertureChange.direction uses brighter, darker, or unchanged. relation uses exact, approximately, or less-than, preserving wording such as "approximately one stop" and "less than one stop" separately from the numeric value. When conversionOptics.present is false, no optical specification other than present is recorded. conversionOptics: null means that accepted published evidence does not establish whether conversion optics are present. When conversionOptics.present is true, all seven specification fields are present and any value not established by accepted published evidence is null. mechanisms: [] means that the product was checked and confirmed to have no applicable additional mechanisms. mechanisms: null means that the presence of additional mechanisms could not be established. Shift, tilt, and rotation mechanisms require movements; use null when the nominal amount cannot be confirmed. Other mechanism types omit movements. Measurements distinguish the maximum from a neutral position from the total end-to-end range, while preserving published directionality and conditions. See value states for how these states differ.

Dimensions, weight, environmental-protection claims, and tripod support (physical)¶

physical records dimensions, weight, official environmental-protection claims, and tripod support established by accepted published evidence.

The Mount Adapter FTZ II demonstrates how dimensions, weight, environmental-protection claims, and tripod support are recorded.

Source: data/records/adapters/nikon/mount-adapter-ftz-ii.json

{
  "physical": {
    "dimensionMeasurements": [
      {
        "widthMm": 70,
        "heightMm": 70,
        "lengthMm": 36,
        "approximate": true,
        "conditions": {
          "excludesProjections": true
        }
      }
    ],
    "weightMeasurements": [
      {
        "grams": 125,
        "approximate": true,
        "conditions": {}
      }
    ],
    "officialEnvironmentalProtectionClaims": [
      {
        "types": [
          "dust-resistant",
          "drip-resistant"
        ],
        "scope": {
          "kind": "product"
        },
        "conditions": {}
      }
    ],
    "tripodSupport": {
      "present": false
    }
  }
}

In this example, the width and height are approximately 70 mm, the length is approximately 36 mm, and the weight is approximately 125 g. conditions.excludesProjections: true means that the dimensions exclude projections, while an empty conditions object means that the weight has no additional conditions. The environmental claim applies to the product and records both dust and drip resistance. tripodSupport.present: false means that the absence of a tripod support mechanism was confirmed. When tripod support is present, a collar assembly and its foot can be recorded as separate components. Use components: null when support is confirmed but its component breakdown is not established. See the shared definition for component fields.

Related pages¶

• Glossary: terms used by this project
• Value-state rules: meanings of omitted fields, null, empty arrays, and false
• Data model: relationships among research results, canonical records, and distributions
• Field reference for lenses and related optical products: fields for lenses, teleconverters, and pinholes
• JSON Schema reference: types, required fields, and allowed values