Omnar Lenses NK35-25 lens product shot on wooden table with dark background

NEWS: Omnar Lenses NK35-25 M-Mount Conversion Available for Nikonos W Nikkor 35mm F2.5

Omnar Lenses has a new lens conversion available for M-mount shooters! Beginning July 2023, the rangefinder coupled m-mount NK35-25 can be yours as long as you have an original Nikonos W Nikkor 35mm F2.5 lens available for rehousing. This will be a limited run and the lenses supplied will have to be in working order with no fungus or haze.

The finished 35mm F2.5 lens design is made up of 6 elements in 4 groups with coatings depending on the version of the lens supplied. Elements rehoused into the Omnar platform include the original optical block and iris from the Nikonos lens. This process removes the optical flat that was added for water-proofing and improves the already stellar performance of the well-loved lens.

Omnar Lenses NK35-25 lens attached to a Leica M camera shot on wooden table with dark background
Image used with permission of Omnar Lenses
Omnar Lenses NK35-25 lens attached to a Leica M camera shot on wooden table with dark background
Image used with permission of Omnar Lenses

The W Nikkor 35mm F2.5 was the standard lens for the Nikonos series of cameras created in 1963 and has had a long run of popularity thanks to its design that corrects spherical and chromatic aberrations despite the relatively wide angle and small size. Because of this and the multi-layered coatings applied to later versions, the lens has excellent colour reproduction and clarity. Unlike the UW Nikonos lenses, the W version can function both underwater and on dry land, making it an excellent candidate for conversion.

Omnar Lenses NK35-25 lens with hood attached product shot on wooden table with dark background
Image used with permission of Omnar Lenses

Quite a few customization options for the Omnar NK35-25 are available. All lenses will be rangefinder coupled from 0.65m to infinity with a short focus throw, but there is an option to add an uncoupled close focus down to 0.35m. Additionally, opt for a light or heavy-focus feel.

Lenses can be finished in black matte, gloss black lacquer, or gloss black with antique brassing. Clients can even add three lines of a small custom engraving on the focus ring.

Lastly, an E46 filter thread can be added to the rehousing as well, however, this does increase the size of the lens.

The NK35-25 conversion price is £1,400 (excluding VAT). For more information about the conversion, see additional sample images, or to get in touch with any questions, head over to the Omnar Lenses webpage here.

Bench in meadow photographed on the M11 with the Omnar NK35-25
Taken on the M11 with the Omnar NK35-25. Image used with permission of Omnar Lenses
Postbox photographed on the Sony A7Riii with the Omnar NK35-25.
Taken on the Sony A7Riii with the Omnar NK35-25. Image used with permission of Omnar Lenses
Flowers next to a white post photographed on the M11 with the Omnar NK35-25
Taken on the M11 with the Omnar NK35-25. Image used with permission of Omnar Lenses

Each conversion project enables the grander vision of expanding on the number of rehousings that can be done as well as introducing more original Omnar brand lenses to market.

Being a curious news hound and not too familiar with building optics, I asked Hamish how the NK35-25 project moves this vision forward a step. (If you are new to Omnar or 35mmc, they are one-half in the same. Hamish founded and is partnered with Chris from Skyllaney Opto-Mechanics in Omnar Lenses)

He replied to my question by explaining:

Every lens Chris works on is part of the development of a future project. We have a bit of a timeline planned – not for specific lenses as such – but more for solutions to particular problems. The Omnar platform was the first piece of the puzzle, but along the way forward there are milestones to make. So for eg, the NK35-25 solves the issue of the rangefinder cam translation for all 35mm lenses (provided they have an actual focal length close enough to 35mm that is). This lens also solved, or at least helped solve the issue of controlling the iris within optical blocks when the iris is built in. This helped the Contax T2 conversion prototypes which has a similar iris control mechanism to the NK35-28.

Going on to describe the next part of the plan, he says:

The next step on from this are optics that don’t come with an iris such as the optic out of the various Yashica cameras. But now we have the control mechanism, it’s just a case of linking this to our own iris instead of one the optic comes with. There are similar developmental milestones tied up in the NK35-18 which are becoming part of the roadmap towards a couple of the Contax G series lens conversions as well as a more simple (cost effective) design for the Bertele 50mm f/2.

Developments do take some time with projects being worked on by Chris (Skyllaney) himself. However, with each conversion project, the program builds for more exciting m-mount lens options in the future.

For more information about Omnar Lenses, the NK35-25 conversion, or any other questions, head over to their website here.

Sources: Nikon Imaging’s Nikonos History

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6 thoughts on “NEWS: Omnar Lenses NK35-25 M-Mount Conversion Available for Nikonos W Nikkor 35mm F2.5”

  1. The Nikonos 35/2.5 lens is amphibious, working quite well in water or air. What advantage or effect will result from removal of the flat element?


  2. Markus Larjomaa

    There’s one thing I don’t quite understand… since adapting LTM lenses to M bodies is super simple, why not make Omnars in thread mount for wider compatibility? Is there a technical reason they have to be M? Or is it more like… ”our customers use the latest digital Leicas and at this price point they’ll only accept lenses in native M mount” or something?My 35mm Summicron is all the wide angle I’ll ever need for my M’s, but I’m still lacking anything wider than 50 for my Barnacks 😉

    Not that I’d necessarily be ready to invest €2k for an LTM 35mm… but I don’t like too modern glass (Cosina/Voigtländer) on my oldest cameras, LTM Nikkors seem to be super rare and priced accordingly, and… oh well, is Canon’s 35/2 my only hope?

    Anyway, keep up the good work! If I had the money I would let Skyllaney overhaul all my current lenses and buy ALL Omnar has to offer. Well, at least one of each 🙂

    1. Ok, so the short answer is the ltm lenses that aren’t 50mm (51.6mm to be precise) are harder to make. The benefit of the m-mount is that it always clocks the lens perfectly to the camera. ltm lenses don’t always clock perfectly. That is to say, the top of the lens don’t always face the top of the camera perfectly. Because of this, it is not possible to use a sloped rangefinder cam – even a fraction of a degree off angle with a sloped cam and the rangefinder will be out of whack. LTM lenses get around this by using dual helicoids with a translation built into them to adjust the speed of a flat cam in relation to the movement of the optics.
      Have a watch of this video, that should help explain what I mean by some of what I have said here.

      1. Markus Larjomaa

        Thanks for the explanation, and the video, Hamish! Once again I learn something completely new about rangefinders! I knew there had to be a techincal reason. Or at least, very few people would swallow the price tag of that much more complex LTM Omnar design 🙂

  3. This Nikon 35 2.5 is a fantastic lens. I have two of them for my Nikonosososos (Nikonosi?), one that I bought to intentionally remove the thick protective glass plate for pure land use. To remove it all you do is remove the big o-ring on the front and it drops out. Be aware that the o-ring also keeps the focus/aperture scale in place so make sure to keep that captured.
    I just use two small pieces of electrical tape because I am lazy and it works…

    Works great, of course, on my Nikonos V – which quite possibly is the greatest street photog camera ever as nothing is built tougher, the heavy steel case muffles all sounds, it has AE as well as manual exposure modes, and it has a huuuuuge VF.

    The camera/lens combo cost me $180 and works perfectly. While I like the idea of re-housing it, the USD $1800 is a record scratch moment. Just looking at B&H filtering for 35mm lenses, there are 24 under $1500, including the Biogon f2 and f2.8, the Voigtlander APO-Lanthar f2, the Nokton 35 1.2 v3, the Nokton 35 1.4 v2 etc.

    With those options, you really have to want this Nikonos lens converted! I’d just use it on a Nikonos, but that’s just me. 🙂

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