Hyalotype (Puhar's photography on glass)
Hialotipia (fotografía sobre vidrio de Puhar)
- Date
- 1841-1842 · confidence medium
- Place
- Kranj, Upper Carniola, Slovenia
- Credited to
- Janez Puhar (Johann Pucher)
- Field
- Communication
⚠️ Disputed: the sources disagree.
What it is
A photographic process by a Slovene priest that produced positive images on glass plates using sulphur, iodine vapour and mercury, without silver salts. Exposure times were comparable to those of the daguerreotype.
Sources give 1841 (a newspaper item in Carniolia) or April 1842 for the invention. The process was never commercialised and has not been reproduced from the published data; the exact place of the experiments (Kranj, Bled, Ljubljana) is uncertain.
What it led to
- recognition by the Paris Academy of Sciences in 1852
- low-cost photography independent of silver chemistry
- surviving puharotypes as a historical curiosity