Canon Serenar 135mm f/3.5 I

Canon Serenar 135mm f/3.5 I

Introduced in December 1952, the Serenar 135mm f/3.5 I is Canon’s faster successor in the 135mm rangefinder class. It combines a coupled LTM barrel with a four-element, three-group optical design and a 1.5 m minimum focus distance.

Optical qualities

Rendering

The f/3.5 maximum aperture offers more focusing flexibility than Canon’s earlier f/4 models while retaining a compact four-element, three-group construction. Wide-open contrast and edge performance depend on sample condition, with stronger uniformity generally available after stopping down.

Handling

The lens focuses to 1.5 m and accepts 48 mm filters. Canon lists dimensions of 56 mm by 97 mm and a weight of 565 g. Its long barrel benefits from careful support when focusing on a compact screw-mount rangefinder body.

History

Development and Launch

Canon marketed the first Serenar 135mm f/3.5 in December 1952 as a brighter development of its post-war long-focus rangefinder lenses.

Production Evolution

The model retained a four-element, three-group layout while moving to a faster maximum aperture and larger 48 mm filter size. Later Canon-branded 135mm f/3.5 versions used revised barrels and progressively lower weight.

Special Editions/Variants

Cosmetic and engraving variations may exist within the first version, but they do not require a separate optical profile without further evidence.

Collector Notes

The Serenar name, substantial chrome barrel and 565 g listed weight help distinguish this first version from later, lighter Canon-branded models. Coupling accuracy and internal clarity are important checks.