#history  

In 1839, John Herschell was responsible for discovering the means to fix images, immersing them in a bath of sodium hyposulfite, the same essential component of current photographic fixatives.

The advantages of the calotype were mainly based on the ease of handling copies on paper and the possibility of multiple reproduction. In revenge, the definition, limited by the presence of the fibers of the negative paper, could not rival the daguerreotype.

John Herschell the father of still photography