The Duplex 120 is a dual-lens camera for 24 stereo pairs of 24 mm-square images on 120 film. It was made by Industria Scientifica Ottica S.R.L. (ISO) in Milan, Italy, from about 1956. It has a pair of fixed-focus ISO Iperang 25mm f/6.3 lenses (a moderate wide-angle lens for this format) and an everset shutter with three speeds (1/25 - 1/100s), plus 'P' ('posa': 'B' shutter). It has a small reverse-Galilean viewfinder at the top. The exposure is controlled by two small knobs, one below the lenses and on the right of the camera (seen from behind), which sets the shutter speed, and one above left which sets the aperture (f6.3-f16). Below the aperture control is a PC socket for flash synchronisation; there is a cold shoe on the left side. The shutter release is a small lever at the top right (again, from behind the camera) of the lens panel; there is a cable release socket near this, on the side of the camera.
The film runs vertically, with the supply spool at the bottom, advanced by a knob on the side. It has two red windows; each number (1-12) must be wound into the lower window for one exposure, then into the upper window for the next. The camera has a tripod bush.
The Super Duplex 120 is a similar camera with focusing 35 mm lenses and a six speed shutter.
- McKeown, James M. and Joan C. McKeown's Price Guide to Antique and Classic Cameras, 12th Edition, 2005-2006. USA, Centennial Photo Service, 2004. ISBN 0-931838-40-1 (hardcover). ISBN 0-931838-41-X (softcover). p449.