In or about 1840, designer/manufacturer Charles Chevalier of Paris produced Le Photographe, a similar but smaller, collapsible camera modeled after the Daguerre camera. Daguerre’s was soon tagged “whole plate” and Chevalier’s, and others that followed, acquired the labels of half, quarter, and sixth plate. Chevalier’s camera could accommodate full plates when rigid, but with supports removed, the camera was collapsible. In its collapsed state, the camera was 3 3/4 inches high; fully extended, it was 11 inches—a considerable difference (A Century of Cameras From the Collection of the International Museum of Photography at the Eastman House, Ethan Lothrop).

The portability of the Chevalier camera was an asset, and a number of manufacturers adopted the concept. Among them was an “improved folding camera, for tourists, travellers, and others,” produced by Horne & Co. of London. Chevalier was a third generation optician. The family business, founded in 1765, was known for the quality of its lenses, especially the achromatic lenses invented by his father Vincent and the optics for camera obscuras (http://camera-wiki.org/wiki/Charles_Louis_Chevalier).

The Chevaliers, dealing with both Louis Daguerre and Nicephore Niepce, introduced the two in 1825, realizing they were conducting similar experiments to achieve persistent photographs. In a break with his family, Chevalier founded his own company in 1832, rejoining the family business in 1841.

“Chevalier developed a new doublet lens for cameras, with focal lens 29cm and aperture f/5.6, six times faster than the lenses he had made for the first daguerreotype cameras. For his lens, the Photographe a Verres Combinés, he won the prize of the Société d’encouragement for improvement of the photographic lens in 1841.”

A Lomography posting claimed, “some 175+ years ago, two messrs. Charles Chevalier and Louis-Jacques-Mandé Daguerre changed history: they gave the world practical photography” (https://shop.lomography.com/us/daguerreotype-achromat-2-9-64-art-lens/).