Hippolyte Bayard’s Direct Positive Process: History, Re-creation, and Characterization

ABSTRACT

Hippolyte Bayard is celebrated for his invention of the direct positive process of 1840. A direct positive process captures an image without a negative. In Bayard’s process, a sensitized sheet of paper is placed into the back of a camera, where the typical negative would have been placed. Direct positives are unique images, however they cannot be easily reproduced. One-hundred-and-eighty years have gone by since Bayard shared his first photographic process, yet, his system remains a mystery. The only extant notes are a series of published letters to the Académie des sciences and to editors in photographic journals. This study explores the scant surviving evidence by re-creating his recipes. Characterization was carried out with densitometry, colorimetry, X-ray fluorescence spectroscopy, X-ray diffraction and scanning electron microscopy.

RÉSUMÉ

Hippolyte Bayard est célébré pour son invention du procédé du positif direct, en 1840. Le procédé du positif direct permet de capturer une image sans l'intermédiaire d'un négatif. Dans le procédé de Bayard, une feuille de papier sensibilisé à la lumière est placée à l'arrière de l'appareil photo, à l'endroit où le négatif aurait typiquement été placé. Les positifs directs sont des images uniques, cependant ils ne peuvent pas être reproduits facilement. Cent quatre-vingts années sont passées depuis que Bayard partagea ses premières images, pourtant son système reste mystérieux. Les seules notes existantes sont une série de lettres publiées à l'Académie des sciences et aux rédacteurs en chef de revues photographiques. Cette étude explore les maigres preuves survivantes en recréant ses recettes. La densitométrie, la colorimétrie, la fluorescence à rayon X, la diffraction de rayons X et la microscopie à balayage électronique furent utilisées pour la caractérisation des éléments. Traduit par Anne-Marie Guérin.

RESUMO

Hippolyte Bayard é celebrado por sua invenção, em 1840, do processo positivo direto. Um processo positivo direto captura uma imagem sem um negativo. No processo de Bayard, uma folha de papel sensibilizada é colocada na parte de trás de uma câmara, onde o negativo típico teria sido colocado. Positivos diretos são imagens únicas; no entanto, eles não podem ser facilmente reproduzidos. Cento e oitenta anos se passaram desde que Bayard compartilhou seu primeiro processo fotográfico, mas seu sistema permanece um mistério. As únicas notas de destaque são uma série de cartas publicadas enviadas para a Académie des Sciences e para editores de revistas fotográficas. Este estudo explora as escassas evidências sobreviventes recriando suas receitas. A caracterização foi realizada com densitometria, colorimetria, espectroscopia de fluorescência de raios-X, difração de raios-X e microscopia eletrônica de varredura. Traduzido por Francisco Vieira.

RESUMEN

Hippolyte Bayard es célebre por su invención del proceso positivo directo de 1840. Un proceso positivo directo genera una imagen sin el uso de un negativo. En el proceso de Bayard, una hoja de papel sensibilizada se coloca en la parte posterior de una cámara, donde se habría colocado el negativo tradicional. Los positivos directos son imágenes únicas; sin embargo, no se pueden reproducir fácilmente. Han pasado ciento ochenta años desde que Bayard compartió su primer proceso fotográfico, sin embargo, su sistema sigue siendo un misterio. Las únicas notas que existen son una serie de cartas publicadas que fueron dirigidas a la Académie des sciences y a los editores de revistas fotográficas. Este estudio explora la escasa evidencia sobreviviente recreando sus recetas. La caracterización se realizó con densitometría, colorimetría, espectroscopia de fluorescencia de rayos X, difracción de rayos X y microscopía electrónica de barrido. Traducción: Amparo Rueda; revisión: Diana Díaz.

KEYWORDS:

• Hippolyte Bayard
• early photography
• direct positive
• densitometry
• X-ray fluorescence spectrometry
• scanning electron microscopy
• history of photography
• salted paper

Sources of materials

#171 Cold Cream Paper

Ruscombe Paper Mill

23 Cours de la Marne

33460 Margaux, France

Ammonium Chloride (A661-500)

Fisher Scientific

112 Colonnade Road

Ottawa, ON, Canada, K2E 7L6

Silver Nitrate, Pyrogallic Acid and Potassium Iodide

Nymoc Limited

24 McGee Street

Toronto, ON, Canada M4M 2K9

Sodium thiosulphate (5160320)

Kodak

3500 Eglinton Ave. W

Toronto, ON, Canada, M6M 1V3

Acknowledgements

The authors would like to thank Lee Ann Daffner and Erin Murphy for their encouragement and insights, Céline Daher of the Centre de recherche sur la conservation who performed a portion of the XRF measurements, and Katia Busch and Carole Sandrin for their assistance with translations.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Tania Passafiume, photograph conservator, Independent Bayard Researcher, Canada. Email: [email protected].

Marie-Angélique Languille, is conservation scientist at the Centre de recherche sur la conservation (CRC) Centre national de la recherche scientifique (CNRS). In 2008, she earned her PhD in physical chemistry. Email: [email protected].

Chantal Garnier, Centre de recherche sur la conservation (CRC), Muséum national d'histoire naturelle, Centre national de la recherche scientifique (CNRS), Ministère de la Culture, Paris, France.