Zunow 5cm f/1.1 Type II

Zunow 5cm f/1.1 Type II

The Zunow 5cm f/1.1 Type II is the redesigned flat-rear version of Zunow's ultrafast rangefinder standard lens. Introduced around 1955, it replaced the original nine-element Type I construction with an eight-element, five-group optical formula.

The flatter rear assembly is the clearest external distinction. The revised design also employed improved hard coatings on air-to-glass surfaces to reduce internal reflections. Original rangefinder-coupled versions are documented in Leica thread and Contax RF mounts.

Optical qualities

Rendering

The Type II retains the shallow depth of field and distinctive character expected from an f/1.1 lens, but it provides better effective brightness and lower flare than the Type I. Wide-open images remain softer toward the edges, with stronger central definition and contrast after stopping down.

The twelve-blade aperture found in documented late barrels preserves rounded out-of-focus highlights over much of the aperture range.

History

Development and Launch

The Type II followed soon after the original lens and addressed the Type I's protruding rear element, flare and wide-open light transmission.

Production Evolution

Later examples carry Zunow Opt. branding and can have black-and-chrome rather than fully chrome barrels.

Special Editions and Variants

Factory conversions exist in which a Type I-style barrel contains Type II optics. Classification should follow the optical construction, so these converted examples belong to Type II.

The Leica screw version is categorized as LTM even when an auction or dealer describes it generically as M39.

Collector Notes

Confirm the flat rear assembly when identifying the version. Aperture blades can be fragile, and internal haze, coating marks and element separation materially affect performance and value.