Leica Lens Adapter for NX10?
January 16, 2010
When Samsung introduced its new NX10 “EVIL” camera, it also created a new NX lensmount standard. (Samsung couldn’t use Micro Four-Thirds lenses, since the NX10’s APS-C sensor requires an image circle 6.5mm larger.)
One of my immediate questions was, could Leica lenses be adapted to the NX mount?
First, a little background:
The Micro Four-Thirds standard set itself the goal of producing DSLR-quality cameras, but in a smaller body.
Thus, µ4/3 is based on a lensmount with an unusually short flange focal distance (aka “register”) of only about 20mm. Because virtually all other camera mounts use longer flange distances, it’s possible to mount a huge variety of lenses to a µ4/3 body, using an appropriate adapter.
Adapters won’t communicate aperture or stop down the lens (except in the case of “original” Four-Thirds lenses). So everything must be done in manual mode. But otherwise, the only limitation is whether some clever machinist has decided there’s enough of a market to crank out a few adapters for some really obscure mount (Alpa, anyone?)
Some of the most revered lenses ever made are ones using Leica’s bayonet M mount—or its predecessor, the 39mm Leica thread mount (“LTM” to its friends). Over the decades, many other interesting Japanese and Russian lens brands have adopted the same mount standards.
Like µ4/3, rangefinder film cameras also have a mirrorless body, and a shallow lens register. But even in the case of LTM or M bayonet lenses, a µ4/3 mount leaves plenty of room for an adapter that maintains infinity focus.With Leica’s own digital camera offerings costing a bit of money, many Leica-mount lens owners are grateful to have another digital alternative—even one with a limiting 2x crop factor.
So could rangefinder lenses work on an NX?
What I’ve attempted to do above (click to enlarge) is to estimate the diameter of the lens throat, scaling from the stated dimensions of the NX10 sensor. With the unknown perspective distortion here, 39.8mm is the maximum possible diameter—it might be smaller.
The quoted flange distance of the new NX mount is 25.5mm. The Leica M bayonet is 27.8mm. That sounds like good news, right? A whole 2.3mm to spare?
Unfortunately, No. The tabs of the M bayonet extend behind the flange by almost 7mm, and are 43.5mm in diameter. Thus they would collide with the inner throat of the NX mount. Doesn’t look like an M-mount adapter is going to happen. (Or, not one that can focus at infinity, anyway.)
Okay, what about 39mm LTM lenses?
The flange distance of LTM is 28.8mm, so we’re safe there. And the threads of an LTM lens truly are 39mm in diameter—maybe more like 38.8mm. They extend about 4.1mm behind the flange.
With the uncertainty of my NX diameter estimate, this is cutting it awfully close—but it’s just possible LTM lenses could squeak into the NX mount.
At the back of an LTM lens, there’s also a protruding inner barrel. On a film body this makes contact with the rangefinder cam, and extends about 7.5mm behind the flange (when the lens is focused to infinity). Will this run afoul of the electrical contacts in the NX mount? Hard to say, until someone can get their hands on a body to try it.
So, sorry to all you Leica M fans. With its 1.5x crop factor, the Samsung sensor could have been an appealing alternative to µ4/3. But it ain’t happening.
I don’t own any M-mount lenses. But I do have some interesting LTM ones I’d enjoy trying on digital. How about that Jupiter-9, which becomes 130e at f/2.0?
I’ve already taken a few swipes at this first Samsung NX model. And if the lens mount really can’t accept LTM adapters, it’ll be very hard to win me back.