Voigtländer Nokton 50mm f/1.5 LTM

Voigtländer Nokton 50mm f/1.5 LTM

Among Cosina's revival of the Voigtländer name, the screw-mount Nokton 50mm f/1.5 stands out as a fast standard lens that has often been measured against far more expensive rivals. Reviewers regularly compare it to the Zeiss C-Sonnar and the aspherical Leica Summilux, and many treat it as a high point of the Cosina Voigtländer line rather than a budget alternative [1]. The lens uses a six-element, five-group double-Gauss layout and couples to the rangefinder through its Leica thread mount, so it works directly on screw-mount bodies and on M cameras with a simple LTM-to-M adapter [1][3].

The barrel is built largely from brass, which gives the compact lens a dense, solid feel in the hand despite its modest weight [1]. It is a physically wide lens to accommodate the large front element, though it remains close in length to a 50mm Summilux [1]. Handling centres on a deeply scalloped focusing ring with a focus throw of roughly 100 degrees and firm damping that suits accurate work at full aperture, while the ten-blade aperture ring turns easily and clicks at half stops [1]. The convenient 52mm filter thread allows the use of common filter sizes and snap-on caps rather than scarcer accessories [1][3]. On a 0.72x finder body there is some finder cut-off, which becomes significant if a hood is fitted, so a vented hood is generally preferred [1].

This screw-mount version is the earlier of the two f/1.5 Noktons and is distinct from the later M-mount Vintage Line lens. Collectors note that the LTM lens carries a different optical formula incorporating two aspherical surfaces, and it focuses to a longer minimum distance than the newer barrel [1][2]. It was offered in chrome and in a black paint finish, the latter developing a worn patina over time [1]. When comparing the two designs, owners report that the optics are broadly similar, with the principal practical differences being filter size and close-focus distance, and some discussion of updated coatings on the newer lens [2][3].

Optical qualities

Rendering The lens renders in a thoroughly modern, double-Gauss manner, combining strong central sharpness with a smooth out-of-focus field. Subjects within the plane of focus are recorded crisply, with sharpness easing slightly toward the corners alongside mild vignetting [1].

Bokeh and transitions Out-of-focus areas are generally soft and creamy, best from f/1.5 through about f/2.8, after which highlight discs begin to take on the polygonal shape of the aperture. Backgrounds with fine structure such as grass can show some swirl, which has been linked to slight barrel distortion [1]. On the related design, the use of an aspherical element can produce onion-ring texture and outlining in highlight circles depending on the scene [2].

Flare resistance The lens is described as controlling flare and ghosting well, retaining clean rendering even when pointed toward a bright light source [1].

Focus shift Owners report essentially no focus shift on stopping down, attributed to the double aspherical surfaces and the modified double-Gauss design [1].

History

Development and Launch The screw-mount Nokton 50mm f/1.5 was part of Cosina's reintroduction of fast Voigtländer rangefinder optics built around the Leica thread mount. Its styling deliberately recalls the early Voigtländer and Leica fast fifties, and the lens was positioned as an affordable high-performance alternative to Leica and Zeiss standard lenses [1].

Production Evolution The original L39 lens was later succeeded by an M-mount Vintage Line version with a redesigned barrel based on the 1950s Nokton. Compared with the screw-mount lens, the newer version changes filter diameter and shortens the minimum focusing distance, while the optical character is reported to be closely related; some users also mention possible coating updates on the later lens [2][3].

Collector Notes The screw-mount lens is identified by its 52mm filter thread and scalloped focusing ring, which separates it from the later M-mount design [1][3]. Buyers should confirm the mount, since the lens is frequently used on M bodies via an adapter and can be mislabelled. One reported mechanical issue is a loosely seated optical group behind the front element caused by an improperly tightened retaining ring, so it is worth checking that internal groups are secure [3]. Note that published figures for the older version's filter size vary between sources; the lens as confirmed here uses a 52mm filter [3].

Sources

• [1] 35mmc. Voigtlander f/1.5 50mm Nokton LTM – Review by Hern Tan. https://www.35mmc.com/29/12/2016/voigtlander-f-1-5-50mm-nokton-ltm/
• [2] phillipreeve.net. Review: Voigtländer Nokton 50mm 1.5. https://phillipreeve.net/blog/review-voigtlander-nokton-50mm-1-5/
• [3] Rangefinderforum. Differences between 50mm 1.5 ASPH LTM and II MC M?. https://rangefinderforum.com/threads/differences-between-50mm-1-5-apsh-ltm-and-ii-mc-m.4796045/