|scanned by Uwe Kulick (Image rights)|
Jumelle cameras (or photo-jumelles) are a style of camera common in the late 19th and early 20th centuries. The first of these was made by Jules Carpentier in about 1892. Jumelle means 'twin', and by extension 'binocular', in French. Some of the cameras from which the term originates are actually disguised as the leather case for a pair of binoculars (see, for example, Wunsche's Photo-Jumelle). Many more are simply rigid-bodied cameras, tapered between the narrow lens board and wider plate holder, giving a shape that only very approximately resembles a pair of binoculars.
Thus the term refers strictly to the shape of the camera; 'jumelle' does not imply a stereo camera: both mono and stereo jumelle cameras were made. Because of the period they were made, most jumelles are plate cameras. Compared to normal field cameras, they are fairly inconspicuous, so they may be thought a type of detective camera.
There are also a few cameras (mostly more modern) which are built into a working binocular viewer, and some of these incorporate the term 'jumelle' in their name.