You’ve Probably Never Seen a Full-Spectrum Color Photo

Science educator Steve Mould‘s newest video sheds fascinating light on an oft-forgotten color photography process. Mould’s video has the grabby title, “You’ve Never Seen a Real Photo,” which is closer to the truth than it sounds.

As is often the case, it is best to start at the very beginning. Back in 1891, Luxembourg-born French scientist and inventor Gabriel Lippmann developed an early color photography process, eponymously named the Lippmann process.

The process works based on interference. As Jon Hilty, a preeminent autochromist and all-around exceptional alternative process color photographer explains, “When a panchromatic fine grained black and white emulsion is put in direct contact with a mirror, the reflected light interferes with itself and creates an interference pattern.”

“The maxima of this pattern activate the silver halides in the emulsion. When developed, the silver in the emulsion reconstructs this pattern when exposed to white light, giving us a color image,” Hilty continues.

What makes Lippmann plates so special, aside from the fact that they represent a pioneering color photography technique that won Lippmann the 1908 Nobel Prize in Physics, is that they are “the only known way to permanently reproduce a full spectrum of color.”

To that end, it’s not possible to see the true effect of a Lippmann plate in a video on a screen. Displays show color using combinations of red, green, and blue pixels, just like how a digital image sensor captures color through its color filter. To overcome this, Mould inspects typical photographs and Lippmann plates provided to him by Hilty using a spectrometer. The difference is immediately clear.

When exposing a Lippmann plate, the actual, physical spectral data is essentially encoded in the photosensitive surface, creating an array of teeny-tiny mirrors. The distance between these mirrors is determined by the wavelength of light that strikes the photosensitive materials, and then preserved through chemical development. This is structural color.

Even today, Lippmann’s invention attracts very serious scientific attention and research. Lippmann plates are “the earliest multi-spectral light measurements on record.”

So why isn’t color analog photography done today using Lippmann’s groundbreaking technique?

“Lippmann plates have their drawbacks,” Mould explains. “Reprints are basically impossible. Exposure times run to minutes, the restricted viewing angle is less than ideal, and they can get a bit washed out if you don’t get the process exactly right. Which is probably why pigment-based RGB photography eventually came to dominate.”

Somewhat ironically, the very same photographer who provided Mould with the Lippmann plates for his new video, Jon Hilty, may be the world’s only living photographer to use the autochrome process that spelled the swift end of Lippmann’s photography. The French Lumière brothers invented the autochrome process in 1903 and brought it to market four years later. In nearly every practical way, it was a superior color photography process.

Photographers with some serious time on their hands can try Lippmann plate photography and autochrome photography for themselves, thanks to Jon Hilty’s exhaustive guides linked just above.

Image credits: Steve Mould. Featured Lippmann plates created by photographer Jon Hilty.