Edmond Becquerel’s First Color Photographs : A Physico-Chemical Approach to the Origin and Stability of Colors - (2015-2018)

Subject and description

Funding : Paris Sciences et Lettres (PSL)

PhD director : Bertrand Lavédrine, CRCC

Supervisor : Marie-Angélique Languille, CRCC

In 1848 Edmond Becquerel developed the very first color photographic process and was able to record the solar spectrum with its own colors. A few prints representing still lifes obtained with the same process are still conserved in the National Museum of Natural History in Paris. The support is a silver plate similar to those used for daguerreotypes that underwent a sensitization step and the positive color image is directly formed onto the sensitized plate. The exposure times were quite long and the resulting photochromatic images could not be fixed which is why this invention was not widely used; however, it was the first response to the problem of colors in photography that some considered crucial in the 1840’s.
Finally, the nature of colors in those plates was not established: it motivated a debate between scientists in the 19th century, and this question is still not solved in the 21th century. The aim of this PhD is to gain insights on the colors of the photochromatic images by studying their sub-microstructures and chemical natures. One of the challenges of this research consists in the high photosensibility of the plates, which implies to develop a specific methodology for studying them.