Voigtlander Dynar 12" (305mm) F6 Lens in Serviced Volute Shutter
Classic vintage Voigtlander lens.
Our best research brought up that the Dynar is the same as the Heliar, but branded for the US market. Your research might turn up more info.
The volute shutter was just returned from service at Flotut's camera repair. The conclusion of the repair was:
All speeds function, however, longer speeds (1/2-3") all fire at 1/2, and the top speed is limited to 1/75. B and T settings work as they should.
The volute shutter is a wondrous device. The F stop setting is created by the aperture blades opening to the selected aperture setting, then closing. There is no separate aperture diaphragm. As a result, the opening is never perfectly round. It has a somewhat of an irregular shape, which adds to the character of this lens.
Covers 8X10 with room for movements, "normal" angle of view.
Includes mounting flange.