In 1871, another Englishman, Richard Meaddox, resolved this problem by replacing collodion by gelatin, a process perfected by Charles Bennet, who demonstrated that gelatinized plates acquired a high sensitivity when they were kept for a few days at 32°Celsius. Not only the gelatino-bromide plates could then be stored before use, but their sensitivity was such that the exposure time could not exceed a fraction of a second.

The story of the shutter started shortly before 1880, because of the high sensitivity of these plates made it necessary to conceive mecanisms able to let light enter the camera for 1/100th and even 1/1000th of a second.
It became necessary to precisely evaluate light intensity, and the light meter then became a real measuring device.




Richard Meaddox

Georges Eastman
The american George Eastman, Kodak founder, conceived, in 1888 , the idea of the supple base. Glass plates were progressively replaced by celluloid rolls.

Photography was still missing color reproduction. The first tries were due to Edmond Becquerel in 1848, then Niépce de St-Victor in 1851 showed that a silver plate coated with a layer of pure silver chloride reproduced colors directly, but in an unstable manner.

In 1869, Louis Ducos du Hauron, in Agen , made the first color photograph applying the principle demonstrated by Maxwell of light decomposition in three primary colors : red, yellow and blue. He made three photos of the same subject, each one through a different filter : a red, a yellow, and a blue one. He obtained three positives that he dyed with the color corresponding to each filter. By superimposing in register the three images, he got the restitution of the colors .





Gabriel Lippman in 1906


 The physicist Gabriel Lippman received the Nobel prize in 1906 for having found in 1891 a way to obtain photos in direct colors on one plate, by an interferencial process prefiguring Holography. Too complicated, this invention remained only a laboratory feat .







Auguste Lumière

The first monoplate color process practicable by amateurs was created in 1906. The Autochrome plate invented by the Lumiere brothers was based upon the principle of the trichromatic synthesis, realized on only one plate by joining to it a mosaic of microfilters in the primary colors realized with minuscule colored grains of potatoe starch.




The discovery by R. Fisher around 1911 of the chromogene developer gave color photography a new direction. It had been noticed that some developers gave images with one color instead of black and white .
The trichromatic principle was used by Agfa to realize in 1936 Agfacolor films, made of three superimposed layers respectively sensitive to blue, green and red. A developer that colored every layer into a color of its sensitivity was invented.The superimposition gave an image in color. The possibility of color reproduction led to improvements in lens manufacturing to transmit acurately the colors of the subject to the film.

In 1935 two americans, L . Mannes and L . Godowsky, improved this process. Bought by Kodak, it was named Kodachrome. If today color films are so sophisticated, nevertheless they still use silver bromide , gelatin and basic principles from Agfacolor and Kodachrome.