Canon 28mm f/3.5 II

Canon 28mm f/3.5 II

The Canon 28mm f/3.5 II is a compact rangefinder wide-angle introduced in January 1957. It uses six elements in four groups and focuses to approximately one metre. Canon's standard LTM version measures about 48mm in diameter, 24.7mm in length and 120g, making it one of the smallest lenses in the company's post-war rangefinder system.

In addition to the familiar Leica Thread Mount version, Canon produced an exceptionally rare factory Contax RF variant engraved Canon Lens CT 3.5/28. The CT version uses an original external bayonet focusing barrel rather than an adapted LTM mount. Available documentation and surviving examples do not establish a different optical formula, so both mounts belong to the same lens profile.

The published 48 × 24.7mm dimensions, 120g weight and 40mm filter size come from Canon's standard version. They should not automatically be treated as exact measurements for the rarer CT barrel without a documented physical measurement.

Optical qualities

Rendering

The 28mm f/3.5 II has the moderate contrast and restrained colour saturation associated with coated rangefinder lenses from the 1950s. It is generally regarded as a capable detail-producing lens, particularly when stopped down.

Sharpness

At maximum aperture, central definition is useful while the outer field is less consistent. Stopping down improves contrast and corner performance. Collector comparisons often describe the f/3.5 lens as more even and refined than Canon's faster 28mm f/2.8, although controlled comparative testing is limited.

Vignetting and distortion

Some light fall-off is visible at f/3.5, as expected from such a compact wide-angle design. It decreases after stopping down. Distortion is normally modest and is unlikely to dominate most photographs.

Flare resistance

The coated optics offer better contrast than Canon's earliest uncoated rangefinder lenses, but strong backlighting can still produce veiling and ghosting. A suitable hood can be useful when the light source is close to the frame.

No mount-related optical difference between the LTM and CT versions has been demonstrated. Any visible difference is more likely to result from condition, centring, coating wear or previous servicing.

History

Development and Launch

Canon marketed the 28mm f/3.5 II in January 1957 during the final major period of its interchangeable-lens rangefinder system. It provided a smaller and less expensive alternative to faster 28mm lenses while retaining rangefinder coupling and a one-metre minimum focusing distance.

The regular version was manufactured in Leica Thread Mount for Canon's own screw-mount rangefinder cameras and for compatible Leica bodies.

Canon Lens CT

A very small number of original Contax RF versions are documented with the engraving Canon Lens CT 3.5/28. Specialist references and surviving auction examples identify these as original Contax or Nikon-compatible rangefinder mounts rather than later conversions.

The CT should be treated as a factory mount version of the 28mm f/3.5 II, not as a separate optical model or special edition. Exact production numbers are unknown.

Production Evolution

Documented lenses occur in chrome and darker finishes. Engraving and barrel details vary, but no confirmed optical redesign within the 28mm f/3.5 II family has been established.

Collector Notes

Collectors should check the front engraving carefully because the 28mm f/3.5 can be confused with Canon's more common 28mm f/2.8.

For a purported CT example, the original bayonet construction, focusing assembly and engravings should be examined closely. The high value and rarity of the CT version make later conversions or incorrectly described lenses a particular concern.

As with other Canon rangefinder lenses from this period, haze, coating marks and internal cleaning damage should be checked before purchase.

Special editions

No separately marketed special edition is confirmed. The Canon Lens CT 3.5/28 is a rare factory mount variant and should not be categorised as a commemorative or special edition.