{
  "study": "What EXIF data photographs still carry",
  "article": "https://www.viallo.app/blog/what-exif-data-photos-still-carry",
  "measured": "2026-09-10",
  "rows": 3000,
  "scored": 2984,
  "excluded": 16,
  "draw": "Wikimedia Commons file namespace, the platform's own random generator, JPEG files only",
  "columns": {
    "row_id": "sha1 of the file title, first twelve hex characters; the title itself is not published",
    "excluded": "1 when the fetch or the parse failed, and such a row is outside every share",
    "uploader_hash": "sha1 of the uploader name, first twelve hex characters",
    "body_serial_exif": "the standard EXIF field 0xA431",
    "lens_serial_exif": "EXIF 0xA435, a lens serial and not a camera serial",
    "serial_xmp": "an aux:SerialNumber element in the XMP packet",
    "gps_block": "a coordinate block is present",
    "gps_all_zero": "the block is present and holds nothing but zeros",
    "whole_file_read": "1 when the file was also read whole and read by exiftool",
    "exiftool_*": "the narrow reading: the group the serial sits in, per exiftool, asking for two serial tags; -1 when the file was not read whole",
    "exiftool_wide_*": "the wider reading the article reports: the same question with every serial tag asked for by name, which is what lifts the count; -1 when the file was not read whole, and a lens serial is excluded because it is not a camera serial"
  },
  "counts": {
    "files_with_make": 1706,
    "files_with_location": 321,
    "files_with_serial_in_file": 401,
    "files_with_serial_in_platform_field": 342,
    "makes": 87,
    "models": 840
  },
  "instruments": {
    "reader": "census-2 2026-09-10",
    "second_reader": "exiftool 13.55",
    "platform": "MediaWiki action=query prop=imageinfo iiprop=metadata"
  },
  "analysis": "tools/analyze.py in the run directory turns this file into every number the article reports",
  "licence": "CC0 1.0, public domain dedication"
}