Sankyo-Kohki Komura 135mm f/2.8

Sankyo-Kohki Komura 135mm f/2.8

The Komura 135mm f/2.8 is a medium telephoto made by the Japanese optical firm Sankyo-Kohki for the Leica thread mount (LTM, also called M39 screw mount). It is one of the rangefinder-coupled lenses Komura offered to owners of screw-mount Leica and compatible bodies, sitting at the longer, faster end of the common 135mm class where most contemporaries opened only to f/3.5 or f/4. The faster f/2.8 aperture is the lens's most distinctive trait and is reflected in its relatively substantial size and mass for the focal length.

Optically the lens uses a compact five-element, four-group telephoto arrangement. It is built in black finish with a 55mm front filter thread, and measures roughly 105mm long and 60mm in diameter at a weight of about 482g, which is heavy for a 135mm rangefinder lens and consistent with the larger glass needed for the f/2.8 opening. The aperture uses a 12-blade diaphragm, giving a near-circular opening across the aperture range. Focusing is rangefinder coupled through the screw mount, with a minimum focus distance of 1.5m, typical of long rangefinder lenses whose close focus is limited by the camera's coupling mechanism rather than the optics. On Leica thread bodies it requires the appropriate 135mm bright-line or auxiliary finder for accurate framing.

Optical qualities

Rendering Reliable, source-grade information on the rendering of this specific Komura 135mm f/2.8 could not be verified during preparation of this entry, so no claims about its sharpness, contrast, bokeh, flare resistance, distortion, or digital behavior are made here. As a five-element telephoto of its era, its character would be expected to follow the general traits of mid-century Japanese rangefinder telephoto designs, but this should be treated as background rather than a documented finding.

Collector Notes

Buyers should confirm that the lens is the rangefinder-coupled LTM version rather than a preset or fixed-mount variant, since Komura produced lenses in several mounts. Because few authoritative references on this exact model could be confirmed, originality of finish, coupling cam condition, and the state of the glass and coatings are best checked in person or against the seller's images before purchase.