Diameter is as short as 3 cm, this surprisingly small camera had been recorded on the Guinness Book as the smallest camera in the world. This camera named "Petal" was launched in 1948 by St. Peter Kogaku, Japan and manufactured mainly for the U.S. For that reason, the instruction written in English was provided with Petal.

Loading the round-shaped film magazine in which a cut-out round-shaped sheet film (diameter of 24 mm.) is inserted in Petal enables it to take 6 pictures. (When a new film is needed, you have to cut out a film along with some coin whose diameter is near to 24mm. from a 35mm film and such.)
f5.6/12mm fixed focus lens is located a little upper side in the center on the camera top. And on the upper side of the camera, there is the direct-view finder and the shutter release trigger. Shutter speeds can be changed either B (Bulb) or I (1/50sec.) by turning the shutter speed dial on the camera top. The knurled roller around the camera has the number from 1 to 6 on it and turining it sets the film to the next exposure.

After this model was introduced Sakura (=cherry blossam) Petal whose shape was changed to an octagonal one.

• First introduced in 1948, by St. Peter Kogaku.
• Lens : fixed focus f5.6/12mm, single element lens
• Shutter speeds : B (Bulb) or I (1/50sec.)
• Viewfinder : direct-view finder
• Film : round-shaped sheet film (Diameter = approx. 24mm.)
• Picture size : Diameter = 6mm. (round shape)
• Body dimensions : W 30 x D 17.5 x H 41mm.
• Body weight : Camera body : 60 grams
  Film magazine : 10 grams