Duplicate listing of the Voigtlander Nokton 28mm f/1.5 — likely the Type I or unspecified version.
The Voigtlander Nokton 28mm f/1.5 appears to be a variant listing of the Voigtlander Nokton 28mm f/1.5 Aspherical VM, Cosina's ultra-fast 28mm for rangefinder cameras. Without the Type II designation, this may refer to the original Type I version or a generic listing. It offers the same f/1.5 speed at 28mm — the fastest available at this focal length for M-mount cameras.
The Type I version is optically good but shows more aberrations wide open compared to the Type II revision. Sharpness improves rapidly when stopping down and is excellent by f/2.8. Bokeh character differs slightly from the Type II — some users prefer the original's rendering. Vignetting is more pronounced in the Type I than the updated design.
Available in Leica M mount and potentially other mounts depending on the specific version. Filter thread is 46mm. Weight is approximately 240 grams. Build quality is excellent with precision metal construction by Cosina in Japan. Manual focus with rangefinder coupling. The focus throw is smooth and well-suited to street photography and zone focusing.
Available on the used market at lower prices than the Type II. Check for rangefinder coupling accuracy and smooth focus. If given a choice, the Type II is optically superior, but the Type I remains a capable and more affordable ultra-fast 28mm for M-mount shooters who want maximum aperture in a wide-angle lens.