Calotype and negative-positive process
Calotipo y proceso negativo-positivo
- Date
- 1835-1841 · confidence high
- Place
- Lacock Abbey, Wiltshire, England, United Kingdom
- Credited to
- William Henry Fox Talbot
- People
- 👤 William Fox Talbot1800–1877
- Field
- Communication
⚠️ Disputed: the sources disagree.
What it is
A paper negative sensitised with silver iodide, from which unlimited positive copies could be made. In contrast to the daguerreotype's unique image, it established the reproducible logic that governed photography until the digital era.
Talbot obtained paper negatives in 1835 but did not publish it until January 1839, after Daguerre's announcement; he patented the calotype in 1841. Hippolyte Bayard obtained direct positives in Paris in 1839.
What it led to
- Reproducible photography: albums, illustrated books (The Pencil of Nature, 1844)
- The photographic printing industry
- Patent litigation that held back photography in England until 1855
- Photomechanical processes and image printing
Built on
- Photography (heliography)1826-1827
- Talbot's photogenic drawings (1835)
- Fixing with hyposulphite (John Herschel, 1839)
- Niépce's heliography
Made possible
- Photographic magic lantern (hyalotype) with limelight1849-1860
- Wet collodion process1851
- Gelatin dry plate
- Photoengraving and photogravure