Camera obscura concerns a scientific phenomenon that has been observed and written about for centuries. It concerns light, and how reflected light can carry information (reversed) that may be “projected” through an aperture.
The earliest known written record of the camera obscura is to be found in Chinese writings called Mozi, dated to the 4th century BCE. It was widely known in the 1500s, with many artists constructing light-safe tents out in the countryside in order to trace landscapes.
The obvious next step to create “photography” is to somehow freeze, or “fix” this image so that it can be removed from the tent. It still has to be reversed but that can be solved later.
This is when I stumbled on this interesting tidbit…
The early science fiction novel Giphantie (1760) by the French author Tiphaigne de la Roche, described something quite similar to photography, a process that fixes fleeting images formed by rays of light: “They coat a piece of canvas with this material, and place it in front of the object to capture. The first effect of this cloth is similar to that of a mirror, but by means of its viscous nature the prepared canvas, as is not the case with the mirror, retains a facsimile of the image.
The mirror represents images faithfully, but retains none; our canvas reflects them no less faithfully, but retains them all. This impression of the image is instantaneous.
The canvas is then removed and deposited in a dark place. An hour later the impression is dry, and you have a picture the more precious in that no art can imitate its truthfulness.”
De la Roche thus imagined a process that made use of a special substance in combination with the qualities of a mirror, rather than the camera obscura. The hour of drying in a dark place suggests he possibly thought about the light sensitivity of the material, but he attributes the effect to its viscous nature.
Now, I am once again amazed at what science fiction writing can generate. It’s true that De La Roche did not see the difficulty of having a lens to focus the image, but why would he? A mirror doesn’t have a lens! He wisely thinks that some sort of solution on canvas should fix the image after exposure. I couldn’t agree more.