Frank Six
The Frank Six (フランクシックス) was a series of 6×6 folding cameras produced at the beginning of the 1950s by the Japanese company Tōsei Kōki. All had an horizontal folding bed and could take both 6×6 and 4.5×6 format pictures when using an inside mask.
The first models
The Frank Six Model I and Frank Six Model 1951 were nearly the same camera. They were roughly similar to the early models of the Olympus Chrome Six, with a tubular optical finder centered on the top plate, an advance knob at the left and an accessory shoe between both. The advance knob was quite high, with a conical base. It had a round leather patch on top on some cameras (Model I?), while it was all metal with an arrow engraved on top indicating the winding direction on other cameras (Model 1951?). There were two red windows in the back, one for each format, protected by a cover sliding under a black plate. These black plates were engraved 4.5 X 6 and 6 X 6 to indicate the picture format. Two red lines in the viewfinder delineated the 4.5×6 picture frame.
The top plate was engraved Frank six in bold handwritten style, and MODEL-I- or MODEL 1951 in square style. At both ends of the body, there was a metal plate marked Frank in handwritten style (Model I?) or FRANK in uppercase square style (Model 1951?). There was a small plate protruding behind the lens and shutter assembly, it was sometimes black with Tōsei Kōki's TK logo filled in white (Model I?), and sometimes chrome with the same logo engraved in black (Model 1951?). The logo was also engraved on the folding struts and embossed in the folding bed's leather.
The lens was a Seriter Anastigmat 75/3.5 with front cell focusing. Its minimal aperture setting was 22, and its maker is unknown. On the Model 1951, it apparently became a C.Seriter, probably because it was now coated.
The shutter had B-1-200 speeds and was marked TKS on the rim, maybe for Tōsei Kōki Shutter (or Seisakusho?). The shutter plate sometimes showed an arrow pattern all around the lens, with no other marking (Model I?) while on other cameras there was simply a thick black circle and a FRANK marking at the bottom (Model 1951?).
McKeown also pictures a very similar version, apparently with MODEL I engraved on the top plate, but with the year 1953 vertically stamped on the folding bed's leather, replacing the TK logo, and Tōsei.O.W 1953 embossed in the back leather. Tōsei.O.W is underlined, and most probably stands for Tōsei Optical Works, a translation of Tōsei Kōki Seisakusho. This model now had a Seriter Anastigmat 80/3.5 lens.
The Frank Six IV
The Frank Six IV had a top housing containing an eye level finder offset to the right and a waist level optical finder offset to the left. The accessory shoe was now at the right end of the top plate, and the shape of the advance knob was different. The rest of the camera is very similar to the Model I. The top housing was engraved Frank.six in handwritten style and MODEL-IV- in red underneath. The shutter was the same TKS with B-1-200 speeds. The lens was now a Tosei Anastigmat 80/3.5, with a red C (certainly for Coated). On the cameras observed, the plate behind the lens was black.
