Canon Serenar 135mm f/4 I

Canon Serenar 135mm f/4 I

The Serenar 135mm f/4 I is Canon’s first post-war long-focus lens in this focal length. Its four-element, three-group optical unit is housed in a substantial chrome barrel, with focus set by distance scale rather than rangefinder coupling.

Optical qualities

Rendering

The four-element, three-group construction provides the compressed perspective and selective depth of field expected from a 135mm lens. Contrast and edge definition improve when stopped down, while flare and veiling haze can be significant in examples with deteriorated internal surfaces.

Handling

Minimum focus is 1.52 m and the lens accepts 40 mm filters. Canon listed a weight of 580 g. Because this first version is not rangefinder-coupled, accurate focus depends on the engraved distance scale or an appropriate external focusing aid.

History

Development and Launch

Canon developed the design during the 1940s and marketed it in March 1948. Early examples predate the formal market introduction, reflecting the company’s transition from immediate post-war production to a standardized lens range.

Production Evolution

The initial mounting arrangement was revised before broad marketing into an LTM-compatible version. Canon followed it in June 1948 with the rangefinder-coupled Serenar 135mm f/4 II.

Special Editions/Variants

Early barrel and engraving differences are part of the model’s production history. They do not by themselves change the optical identity recorded in this profile.

Collector Notes

The uncoupled focusing system is the key functional distinction from the Type II. Buyers should also inspect the heavy barrel, focusing action and internal glass for haze.