As other cameras of the jumelle type, the body of the camera tapers toward the front. Its construction is unusual because it has an innovative plate-changing method. The body is constructed as two half-boxes, one inside the other (or a box and its lid). The two are hinged together at the front, and the upper part can be lifted up at the back, so the whole thing has something of the appearance of a fire-bellows. The upper part contains a plate magazine, and lifting and lowering it serves to move the most recently exposed plate from the front of the magazine to the back (the camera must be held with the lens uppermost for this operation, as it relies on the weight of the plate). The camera and its plate-changing mechanism are the subject of a patent by Lucien Joux.
The camera appears to have been substantially redesigned in around 1898. Collection Appareils reproduces an extract from l'Annuaire de la Photographie of 1898, in which the Sténo-Jumelle is described as of all-metal construction, and so more compact. Earlier cameras, including some of the examples linked below, have part-wooden bodies.
Examples of the camera have various lenses, mostly by Krauss, including an f/8 Krauss-Zeiss Anastigmat and an f/4.5 Tessar, also made by Krauss under licence, (the Tessar itself was only patented in 1902, so this must be a late example of the camera). One example has a lens by Chevalier. The 1898 information at Collection Appareils lists lenses for the metal-bodied camera as f/8 Zeiss Series IIa anastigmats (110 mm and 136 mm for the 6.5x9 cm and 9x12 cm cameras respectively; these are presumably the Krauss-Zeiss lenses seen on the examples linked here), or Goerz Series III anastigmats (110 mm f/7.7 for the smaller camera, 130 mm f/7.1 for the larger); no examples with these Goerz lenses have been seen.
The 1898 information at Collection Appareils refers to helical focusing on the lens (down to 1.5 metre for the 6.5x9 cm camera, and 2 metre for the 9x12 cm one). This is visible in some of the examples seen; The others have a large lever on the left of the body, behind the shutter unit, which may be for focusing.
The shutter is a guillotine type, behind the lens: Frans Jacobs in his blog The Camera Collector stated that it is a five-speed shutter. The speed selector and I/B/T selector are on the lens board. There is a Newton-type finder on the top, with an aiming pointer in front of the glass.
- 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). p453.
- Sténo-Jumelle at Sylvain Halgand's Collection Appareils, including a substantial extract from l'Annuaire de la Photographie of 1898.
- German patent DE 84894 (C) and Swiss Patent CH 9283 (A) of 1894, describing the Sténo-Jumelle camera and its plate-changing mechanism, at Espacenet, the patent search facility of the European Patent Office.
- US Patent 538736 of 1895 in the name of Lucien Joux and Jules Marchal, describing the same camera, at Google patents.
- Sténo-Jumelle 6.5x9 cm camera serial no. 693 with a 110 mm f/8 Krauss-Zeiss Anastigmat sold at the second/third Westlicht Photographica Auction, on 23 May 2003.
- Sténo-Jumelle 9x12 cm camera with 136 mm f/8 Krauss-Zeiss anastigmat and de luxe brown leather covering, in the '2009 Highlights' page at Auction Team Breker.
- Sténo-Jumelle 6.5x9 cm camera also with Krauss lens sold in May 2006 by Auction Team Breker in Cologne.
- Sténo-Jumelle 6.5x9 cm camera with 112 mm f/4.5 Tessar sold at the tenth Westlicht auction, on 18 November 2006.
- Sténo-Jumelle 6.5x9 cm camera serial 3695, with a Chevalier lens, sold at the fourth Westlicht auction, on 22 November 2003.
- The camera was formerly shown at Frans Jacobs' blog The Camera Collector (http://thecameracollector.skynetblogs.be; not retrieved June 2020). Jacobs' stated that the camera has a five-speed shutter.