International back for Voigtländer Avus 9x12

thingiverse

There are lots of different folding cameras for 9x12 glass plates from the beginning of the 20th century. Popular examples are the Voigtländer Avus or Bergheil cameras as well as Ernemann, Zeiss ICA, Steinheil, but there are lots of different brands and builds which are quite similar. In rare cases you will have a clean and working camera, an intact ground glass and the right metal cassettes and the often missing (and thus quite rare) inlays for sheet film in the 9x12cm format. So you have your camera mechanics working, the lens is clean, the shutter is firing at correct speeds, but you are either missing the ground glass insert or cassettes with sheet film inlays? Read on, because you could switch over to my international back for standard 4x5 inch (or 9x12cm) cassettes, including a fitting ground glass back. Prerequisites: Your camera should have rails of the "Normalfalz" type, typically found at Voigtländer cameras, but IIRC also on AGFA or Zeiss Cameras. Some manufacturers used other rail geometries - in this case you would have to create a customized adapter plate.. Parts to print: 1x adapter plate (this plate slides into the metal rails on the camera's back) 1x cassette holder (glue it to the adapter plate) 1x cassette holder top (this is optional) 1x ground glass frame 2x ground glass holders 3rd party parts: 1x 9x12cm ground glass 4x 3x12mm screws 2x rubber rings some hints: 1. fitting the cassette holder to the adapter plate may require a little bit sanding/filing 2. mount the ground glass with the matte side down; when printed correctly, we have the "official" measurements as for standard cassettes. In comparison to the standard ground glass, my increases the distance to the lens a little bit (about 5-6mm) 3. if you want to work with the focusing scale (on the focusing rails), you will have to adjust it to the new film plane Update 2019-03-02: updated the ground glass holder, the original holder didn't have enough tension to hold down the ground glass.