S Lenses


Serenar 135mm f/4 I

  • Specifications
  • Block diagram
Marketed March 1948
Original Price 23,320 yen
Lens Construction (group) 3
Lens Construction (element) 4
No. of Diaphragm Blades
Minimum Aperture 16
Closest Focusing Distance (m) 1.52
Maximum Magnification (x)
Filter Diameter (mm) 40
Maximum Diameter x Length (mm)
Weight (g) 580

The trial production of this lens started in 1941. Canon Inc. started as “Seiki Kogaku (Precision mechanics and optics)”. This was the first interchangeable lens for Seiki Kogaku and it was advertised in the May 1947 issue of the monthly magazine “Kouga”. The focus control system is not coupled to the rangefinder and focus is decided by guess. The original standard bayonet mount was changed to the S mount, before it was marketed as the first interchangeable lens for Seiki Kogaku. This series of lenses were named “Serenar” by a Canon employee in an in-house naming contest. The word “Serenar” was coined from “Serene”, the name of the sea on the moon (the Sea of Serenity) and an adjective meaning of “tranquil”.

Block diagram