The Dallmeyer Dual is a 4.5×6 folding camera, sold in 1931. It has an unusual aspect, with vertically oriented barn doors and a lens plate mounted on scissor struts. The lens and shutter unit is mounted on a focusing helical. The lens is a Dallmeyer Dalmac Anastigmat 3" f/3.5, and the shutter is a rimset Compur (T, B, 1–250, self-timer). The duralumin body is leather covered, there is a folding frame finder and a folding leg with a curved shape.
- s/n D109, lens no.143137
- s/n D125, lens no.143365
- s/n D154, lens no.143852
- s/n D210, lens no.145891
- Christies auction catalogue: "Cameras and Optical Toys" (11 March 1993), lot no.312.
- Channing, Norman and Dunn, Mike. British Camera Makers. An A-Z Guide to Companies and Products. London : Parkland Designs, 1996. ISBN 0-9524630-0-8 P.40.
- 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). P.240.