Voigtländer APO-Lanthar 50mm f/3.5 Type I

The Voigtländer APO-Lanthar 50mm f/3.5 Type I is a compact manual focus standard lens with the VM bayonet, compatible with Leica M. It carries the APO-Lanthar name, which Cosina uses for its highest performance apochromatic designs, in a small and slow package. Cosina announced it in February 2024, and it was released later that year. It is one of two versions: Type I, described here, and Type II, which focuses closer and takes a different filter size.

Optical design

The lens has 8 elements in 6 groups, four of which are made of anomalous partial dispersion glass. According to Cosina, the apochromatic design thoroughly eliminates aberrations, including axial chromatic aberration, and aims at the highest resolution and contrast. The aperture range is f/3.5 to f/22 with 10 blades. The image circle covers the full frame format.

Focusing and handling

Focusing is manual through a precisely machined all-metal helicoid. The lens is coupled to the rangefinder and can focus down to 0.45 m. A click marks the end of the rangefinder coupled range at 0.7 m, so you can feel when you leave it, which Cosina points out is helpful on cameras with live view. A screw-in metal hood and a matching metal cap are supplied. Cosina notes that the black lens with a black mount is not recognised by cameras that read a 6-bit code, and that lens detection should then be switched off.

Build and size

Type I comes in two versions. The two-tone black and chrome version uses brass and weighs 245 g. The matte black version uses aluminium and weighs 150 g. Both are 45.0 mm long with a diameter of 52.0 mm and a 34 mm filter thread. The database entry uses the brass weight.

Where it fits

Type II is the other version of the same optical design: it focuses to 0.35 m and uses 39 mm filters, with 250 g and 175 g models. For Leica M, other standard lenses in the database include the Voigtländer APO-Lanthar 50mm f/2 (288 g), the Leica APO-Summicron-M 50mm f/2 ASPH (300 g) and the Zeiss Planar T* 2/50 ZM (230 g). Compared with these, the f/3.5 lens gives up speed in return for size.

Pros and cons

Pros

• Apochromatic design with 4 elements of anomalous partial dispersion glass
• Compact, 45 mm long, and as light as 150 g
• Focuses down to 0.45 m
• Metal hood and cap included
• Choice of brass or aluminium construction

Cons

• f/3.5 is slow for a standard lens
• Manual focus only
• Type II offers closer focusing and 39 mm filters
• Black version with black mount is not read by 6-bit code cameras

Verdict

The APO-Lanthar 50mm f/3.5 Type I suits photographers who put apochromatic correction and a very small package ahead of speed. It is a niche lens for Leica M and VM cameras, and the choice between Type I and Type II mostly comes down to the minimum focus distance and filter size.