Topcor-S 5cm f/2, a standard lens for the Leotax, manufactured by Tokyo Kogaku. It features a Leica screw mount with rangefinder coupling. The optical design consists of 4 groups and 6 elements. The filter diameter is 40.5mm. This is a mid-production model of the Topcor 50mm f/2, distinguished by the black band around the aperture ring and helicoid scale. The barrel is made of brass, giving it a solid, weighty feel.
The aperture click stops follow a standard progression of f/2, f/2.8, and f/4, with intermediate markings for each third stop. The infinity lock knob is particularly well-crafted, showing exceptional attention to detail. Unlike many Japanese Leica copies, this lens exhibits no roughness whatsoever. It is a true testament to Tokyo Kogaku’s precision craftsmanship and dedication to quality.
In terms of rendering, the lens delivers sharp, well-defined images even at full aperture. The in-focus areas are crisp and refined, while the out-of-focus background has a distinctive, slightly coarse character—a hallmark of classic vintage lenses. Color reproduction is excellent as well. It’s an outstanding lens. Even our staff made the test shots were captivated by its texture and rendering quality.
The exterior is in beautiful condition. While there are some minor scuffs and light signs of use, all parts have been well preserved, maintaining their fine texture.
Fully overhauled in February 2025. The aperture and helicoid operate smoothly, and the rangefinder coupling works perfectly.
There are a few very faint hairline cleaning marks on the inner elements, along with slight coating wear on each surface. However, the glass is crystal clear—remarkably well-preserved. The test shots also yielded excellent results, allowing you to fully enjoy the unique rendering characteristic of Topcor lenses.
Sample images have been uploaded to our test gallery. Though an affordable vintage lens, it delivers sharp, high-quality images that truly showcase Tokyo Kogaku’s precision craftsmanship.
