The Nadar Express Detective is a French-made detective-style camera associated with the Parisian photographer and studio operator Nadar. As a 19th-century French detective camera, it belongs to a category of discreet, hand-held plate cameras designed for candid use rather than studio work.

Sales data for the Express Detective is extremely thin, with a single UK auction hammer result on record at £2,000 in 2018. Because that figure reflects one wholesale saleroom outcome rather than a retail or dealer asking price, it should be treated as an indicative data point rather than a reliable market value in today's 2026 market; what a comparable example sells for now would depend heavily on condition, completeness and provenance.