Film Cameras

35mm Focal-Plane Shutter Scale Focusing Camera

JS (Popular Model with Slow Speeds)

  • Japan
  • Americas
  • Europe, Asia, Oceania
  • Outline
  • Specifications
Marketed 1939
Original Price

Camera with slow shutter speeds from 1 sec. to 1/20 sec. but no rangefinder. Geared for close-ups, photomicrography, astrophotography and other special applications which required slow shutter speed speeds.

According to Canon records, only 50 were made. Other details and the original price are unknown. Around 1939, Seiki-Kogaku was starting to make its own lenses. It made a prototype, Tessar-type 50mm f/4.5 lens (4 elements in 3 groups) and Sonnar-type 135mm f/4 lens (4 elements in 3 groups) without a rangefinder coupling. “Serenar” was chosen from among in-company suggestions for the name of the lenses. The name is probably based on the name of a sea on the moon.

It was not until 1947 when the company started making usable lenses for its cameras.

Type 35mm focal-plane shutter camera
Picture Size 24 x 36 mm
Normal Lens Nikkor 50mm f/4.5
Lens Mount Threaded (non-universal)
Shutter Two-axis, horizontal-travel focal-plane shutter with cloth curtains. Single-axis rotating dial for 1, 1/2, 1/4, and 1/8 sec., and single-axis rotating dial for Z, 1/20, 1/40, 1/60, 1/100, 1/200, and 1/500 sec.
Viewfinder Reversed Galilean viewfinder. Focusing with distance scale.
Film Loading &
After top plate removal, drop-in bottom loading. Advances with camera-top knob.
Frame Counter Manually set from 0 to 39 at base of camera-top rewind knob.
Film Rewind Camera-top knob
Dimensions &
136.5 x 69 x 30.5 mm, weight unknown