A group of researchers from EPFL’s Audiovisual Communications Laboratory had a unique opportunity to investigate some of the very first color photographs ever made, which were originally produced by scientist and inventor Gabriel Lippmann.
Gabriel Lippmann won the 1908 Nobel Prize in physics for his method of reproducing colors in photography, and his original photographic plates and images are usually inaccessible to the public and securely locked away in vaults for safekeeping. But as SlashGear reports, in this special case they were shared with a group of researchers to allow them to study his multispectral imaging method.
The Luxembourg-born physicist and inventor is renowned for his invention of a color reproduction method, which is based on the interference phenomenon, where standing waves are produced as a result of the light reflecting back upon itself by a mirror.
Modern photographs are created by taking three measurements for red, green, and blue, which are stacked, however, the researchers “discovered that Lippmann’s historical approach typically captured 26 to 64 spectral samples of information in the visible region.”
Although Lippmann’s technique is practically obsolete today, it did enable “gravitational waves to be detected and which is the foundation of holography and much of modern interferometric imaging.”
EPFL researchers explain that a similar process, albeit more simplistic, can be observed through light reflection on soap bubbles where colorful reflections are visible. The difference is that Lippmann’s plate has multiple layers compared to just two in soap bubbles, which means that the colors produced by Lippmann’s process are more vibrant.
The team of researchers said that Lippmann’s images and plates represent “the earliest multi-spectral light measurements on records,” and they were interested to find out whether it would be possible to accurately recreate the original light of these historical scenes. Additionally, researchers wanted to explore whether it is possible to create digital copies of the original photographs and also to further understand how the technique worked.
After replicating the century-old light by creating an algorithm that retrieved the light captured and comparing it to the original, the team found that some of Lippmann’s images contain distortions, although the colors reproduced appeared accurate.
The team of researchers has already built a prototype of a digital Lippmann camera and believe that revisiting Lippmann’s technique is beneficial for future technological development, and are “intrigued by the possibilities of multi-spectral image synthesis as well as new multi-spectral camera, printing, and display designs.”
The full research article and its findings, titled “Shedding light on 19th-century spectra by analyzing Lippmann photography,” has been published in Proceedings of the National Academy of Sciences website here.