Rediscovering Ducos du Hauron's Color Photography through a Review of His Three‐Color Printing Processes and Synchrotron Microanalysis of His Prints

Abstract

Louis Ducos du Huron (1837Huron ( -1920 dedicated his entire life to the elaboration of physical-chemical processes for color photography.This study aimed at highlighting his unique contribution to three-color printing through 1) an in-depth review of the many protocols he published and 2) the synchrotron-based IR and X-raym icroanalysis of fragments sampled in three artworks.D ucos du Hauronsm ethod relied on the preparation and assembly of three monochromes (red, blue,y ellow). This study brings to light complex multistep recipes based on photochemistry (carbon print), organic,a nd inorganic chemistry.T he various ingredients involved (e.g., pigments,dichromate gelatin, collodion, resin) were identified and localized through their spectroscopic signature,c onfirming the relevance of synchrotron spectromicroscopyf or the characterization of historical photographs.T he impressive correlation between texts and chemical analyses calls for aw ider application to the history of photography.