The EXA 1a is a mechanical SLR camera body with collapsible top-view finder. It's made for lenses with the EXA-bayonet fitting, among them many of the famous old Meyer-Optik Görlitz lenses. One of the standard lenses made for the EXA is the Meyer-Optik Domiplan 1:2.8/50mm . When this lens is mounted on the EXA its aperture release lever is located exactly over the shutter release button which is placed on the camera's front side beside the lens mount. This construction allows depth-of-field preview by pressing the lens's lever half way, and shutter release with aperture release at once by pressing it down fully. The mirror swings back when the film is advanced.