Collodion dry plates had been available since 1855, thanks to the work of Désiré van Monckhoven, but it was not until the invention of the gelatin dry plate in 1871 by Richard Leach Maddox that the wet plate process could be rivaled in quality and speed. The 1878 discovery that heat-ripening a gelatin emulsion greatly increased its sensitivity finally made so-called "instantaneous" snapshot exposures practical. For the first time, a tripod or other support was no longer an absolute necessity. With daylight and a fast plate or film, a small camera could be hand-held while taking the picture. The ranks of amateur photographers swelled and informal "candid" portraits became popular. There was a proliferation of camera designs, from single- and twin-lens reflexes to large and bulky field cameras, simple box cameras, and even "detective cameras" disguised as pocket watches, hats, or other objects.
The short exposure times that made candid photography possible also necessitated another innovation, the mechanical shutter. The very first shutters were separate accessories, though built-in shutters were common by the end of the 19th century.