Omnar NK35-18

The Omnar NK35-18 is a M-mount lens for Leica rangefinder cameras. Leica price index ↗

Reference maintained by Thomas Boots

Model number(s): NK35-18

Focal Length: 35mm

Aperture: 𝑓/1.8

Release Year (from): 2023

Production Year (to): 2023

Diameter: 51 mm

Length: 29.1 mm

Minimum Focus Distance: 0.35m

Elements in Groups: 7/5

Aperture Blades: 9

Mount: M

Material Weight: Brass, 194g

https://omnarlenses.com/

Omnar NK35-18

The NK35-18 is not a newly computed optic but a rehousing project: Omnar (the lens brand of UK workshop Skyllaney Opto-Mechanics) takes the optical block of Nikon's S-mount W-Nikkor 35mm f/1.8 and rebuilds it into a rangefinder-coupled Leica M-mount barrel [1][2]. The donor lens matters historically, because the W-Nikkor 35mm f/1.8 was the fastest wide-angle of its day when it appeared in the mid-1950s, beating Leica to a sub-f/2 35mm by several years until the 35mm Summilux arrived in 1960 [3]. The conversion keeps that 7-element formula and brings it to modern M bodies with full rangefinder coupling, something the original S-mount glass cannot do without modification because its rear group is too large to clear the M rangefinder mechanism [1][3].

Omnar offers the NK35-18 as a made-to-order conversion rather than a stock product. The customer supplies a clean, working donor lens, and the workshop CNC-machines a slimmer rear optical cell so the block clears the rangefinder swing arm, retaining the original aperture ring and front filter thread; because of these changes the conversion is non-reversible [1]. The lens is designed, machined, hand painted and hand assembled in the UK, and uses an all-brass barrel [1][2]. It is rangefinder coupled from 0.65 m to infinity with a short focus throw, with an optional uncoupled close-focus range continuing down to 0.35 m [1]. Buyers can specify a light or heavy focus feel, several finishes (black matte, semi-gloss black, silver chrome, and gloss black with antique brassing) and custom engraving on the focus ring [1]. The compact result protrudes only about 29 mm from the camera and weighs under 200 g [1].

Because both the original and Nikon's later reissue of the 35mm f/1.8 can be used as donors, individual NK35-18 lenses can differ in their coatings depending on which donor was supplied [1]. The current housing design was developed with cinematographer Jean-Marc Ferriere, who wanted to use his 2005 reissue lens on M-mount cameras with full coupling and assisted with the design and beta testing [1]. The conversion batch tied to the original 2023 release closed in May 2023, with further runs offered on request [1].

Optical qualities

Rendering The underlying W-Nikkor uses a modified double-Gauss design with single-layer blue and amber coatings and lanthanum glass [3]. Reviewers describe it as sharp wide open with a slight softness in the highlights, holding a moderate level of contrast even at maximum aperture and giving solid, well-defined images [3]. Color rendering is noted as vibrant and true to life, with reds and greens reproducing particularly well [3].

Distortion and vignetting The front and rear elements were originally computed for an f/1.4 lens but optimised at f/1.8 to keep vignetting in check, which makes the lens usable wide open with well-controlled corners [3]. Stopped down to about f/2.8 it is reported to reach excellent sharpness with no obvious distortion [3].

Bokeh and transitions The converted lenses are described as having attractive bokeh and pleasing focal transitions alongside their vibrant color, characteristics carried over from the original Nikkor optic [2].

History

Development and Launch The NK35-18 originates from Nikon's W-Nikkor 35mm f/1.8, marketed as the world's first super-speed wide-angle and a premium option for Nikon's 1950s rangefinder cameras, reflecting Nikon's effort to outpace German makers with an optic faster than f/2 [3]. The original LTM version of the W-Nikkor is regarded as scarce, with collector accounts citing roughly 1,500 made for Leica thread mount [3]. Omnar's conversion project, released in 2023, adapts the more common S-mount version into an M-mount, rangefinder-coupled lens, with the housing developed in conjunction with cinematographer Jean-Marc Ferriere [1].

Production Evolution The NK35-18 is built to order rather than mass produced, so units vary by donor lens, coatings, focus feel, finish and engraving [1]. Skyllaney/Omnar machine a new slimmer rear cell to clear the rangefinder mechanism while keeping the original aperture ring and filter mount; the modification is permanent [1].

Collector Notes Because the lens depends on a donor, buyers should verify that the supplied W-Nikkor is haze and fungus free before conversion, as Omnar requires a good working-order lens [1]. The conversion is non-reversible, so a converted example cannot be returned to S-mount, and the original LTM W-Nikkor (distinct from the converted S-mount used here) remains the rarer collector item in its own right [1][3]. Confirm which donor and coating version a given NK35-18 carries, and check the all-brass barrel finish and any custom engraving against the original order specification [1][2].