Kodak Duo Six-20

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Revision as of 19:20, 16 January 2012 by Ektarama (talk | contribs) (revision of rangefinder information)
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The Duo Six-20 is a 4.5×6 horizontal folder made by Kodak AG from 1934 to 1940. As the name implies, it utilized 620 roll film.

The original model has a folding optical finder (though some f/4.5 models had a simple frame finder without optics) and a key for film advance on the left of the top plate. On the right side of the top plate is a depth of field calculator dial. Informally referred to as the "art deco" model, the top plate is painted black and metal parts are nickel plated. Produced from 1934 to 1937, it originally sold for $57.50[1] (app. $900 USD in 2007).

The Duo Six-20 Series II, has modified folding struts, a chromed top plate and metal parts, an advance knob replacing the original key, and an accessory shoe (USA models only). The shutter release was moved from the lens mount (where the cable release socket remained) to the top plate.

The Series II cameras have been found labled as both Duo 620 (an early 1937 example with f/4.5 Kodak lens) and as Kodak Duo Six-20 Series II (a 1938 example with f/3.5 Kodak lens).

Produced from 1937 to 1939, the Series II model also originally sold for $57.50 USD[1].

The non-rangefinder Duo-620 was available in two shutters, the Compur and the Compur Rapid. A number of different lenses were offered:

European models

  • Zeiss Tessar f/3.5 7cm
  • Schneider Xenar f/3.5 7.5cm
  • Schneider Xenar f/4.5 7.5cm.


  • Kodak Anastigmat f/3.5 7.5cm
  • Kodak Anastigmat f/4.5 7.5cm

The f/4.5 lenses utilized front element focusing, while the f/3.5 lenses were unit-focusing.

There is some confusion over the origins of the Kodak Anastigmat lenses on cameras on cameras imported to the United States. There are numerous claims that the lenses are simply re-branded Xenars, while Kodak (in 1938) clearly described the f/3.5 lens as a triplet[2]. To further complicate the issue, the f/4.5 model pictured here has a triplet lens, while the f/3.5 model pictured has a 4 element lens like the Xenar.

Duo Series II with Rangefinder

The last model of the Kodak Duo is the rare rangefinder model with a combined range- and view-finder inside the top housing. With this model the single film counter window was moved to the top left of the back, replacing the two window system of the earlier model that was located at the bottom right of the back. The button that opens the camera front door was moved to the bottom plate of the camera from it's previous location on the camera top. Cast metal strap lugs were placed at the sides of the top housing.

Perhaps the most significant design innovation of the new model was the introduction of automatic indexing film winding, eliminating the need to look at the ruby window after every shot. After frame number 1 was advanced to show in the window, all frames after that would advance to the next frame by turning the winding knob until it stopped. This may have been a first for folding medium format cameras. The Duo's index film advance system is very similar to the indexing system used in the Monitor Six-20. One can speculate whether the design was accomplished in Germany or the U.S., but the earliest Monitors seem to date from 1940, indicating that perhaps the design came from the Nagel engineers.

The new model was introduced in the same month that Germany invaded Poland (September of 1939), which was very unfortunate timing. Few of these cameras were made, as all camera production was halted by Kodak AG for war materials production (including aviation bomb sights) in mid 1940. Examples of the rangefinder Duo Six-20 in the collection of Flickr's Ektarama have backs embossed Kodak Duo 620, printed all on one line (S/N 334140K Xenar f/3.5), Kodak Duo Six-20 Series II, printed on two lines (S/N 332904K Kodak f/3.5), and Kodak Duo Six-20 Series II, printed on two lines with Made in Germany at the very bottom center of the back (S/N 335183K Xenar f/3.5). The serial numbers of these 3 examples span 2279 numbers. If the numbering system was in linear progression, we can be sure that at least 2279 examples of the last Duo model were produced. Sadly, when camera production resumed at Kodak AG Nagelwerk after the war, the Duo Six-20 Series II rangefinder model was discontinued.

The Duo 620 originally sold for $84.50. [1]( app. $1300 USD in 2007).

The rare RF model was sold both in the U.S. and Europe, with a Compur Rapid shutter and a Kodak Anastigmat f/3.5 7.5cm in the U.S., and Xenar 3.5 in Europe. There are Japanese copies of the Duo, including the Semi Prux copying the original model, and the Roavic, Apollo and Mikado, copying the body of the Series II with the addition of a top housing.


  1. 1.0 1.1 History of Kodak Cameras at www.kodak.com
  2. Kodak Lenses and Shutters


  • 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. 491.
  • Brian Coe, Kodak Cameras - The First Hundred Years, Hove Foto Books, 1988


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