The NiSi NM-180 focusing rail - a new standard for manual stacking precision
/The affordable rail that changes everything…
… is the amazing NM-180 Macro Focusing Rail from NiSi. Despite the addition of a couple of fairly useless features, like the legs and fold away handle, this rail is way out in front of the competition when it comes to accurate, repeatable focus stacking.
Please note that some of the links in this article are paid links, meaning that I, as a member of the Amazon Affiliate program, may earn from qualified purchases made using one of these links.
If after reading this post and viewing the video review, you decide to add this precision rail to your macro setup, you can find it right here:
So, what makes this rail so special? There are dozens of other rails available in this price range, and I have owned or test-driven most of them over the years, but the NiSi NM-180 is in a class of its own. And the reason is found in the rail’s precision.
4:1 magnification using 100 micron steps, with the manual NiSi focus rail
As I discuss in the accompanying video, there are several features of this rail that are cool to look at, but of absolutely no use in actual focus stacking. The legs, which make the device unstable by raising the center of gravity to a dangerous height, have no role in high-magnification stacking. Even with a full camera/lens load, the rail will not stay still when trying to stack while the rail is supported by these screw-out legs. Similarly, the fold away handle seems more like a gimmick than a useful feature. The handle requires a large eccentric base which gets in the way when the rail is secured to a solid base, necessitating some kind of raised platform to keep the handle from striking the floor of my macro cage.
The odd handle and odder feet on display
Another negative can be found by flipping the rail on its back - there is only one threaded mounting point on the base. I’m not sure why they went with one instead of at least two, but I am guessing that the designers envisioned this as primarily a tripod mounted rail. I only ever use manual rails that are firmly bolted to my macro cage, to minimize the vibration or accidental repositioning of the rail when mounted on a tripod. After making the video, I realized that the solution to mounting the rail to a base was staring me in the face all along - the dovetails! The full-length Arca Swiss dovetails are a very nice touch for mounting the rail onto another QR clamp, allowing for two rails to work in tandem as an X-Y system - a very useful setup for stacking and stitching projects. But they can also be used to mount the rail in the macro cage, using two or more QR clamps that are attached to the floor of the macro cage.
Where the NiSi rail shines - accuracy
So, after listing several disappointing features, why am I going to purchase one of these rails for my own personal use? The answer lies in how this rail does what you bought it for - focus stacking! it is incredibly precise for a manual rail. The materials and engineering are all top notch, with very tight tolerances throughout. There is little, if any appreciable backlash in the system and the lead screw mechanism is so well made, there is no laxity whatsoever in the camera platform. As a result, with the addition of a single small indexing pin, it is possible to use this rail at step lengths as small as 25 microns - unheard-of in rails in this price range. And that one fact makes up for everything else I have criticized about the rail. It does what it is made to do, and it does it better than any other manual rail I have ever used.
As the subjects get smaller, the NiSi rail shines
The QR plate atop the rail is designed to turn through 360 degrees, which is very handy for mounting your camera quickly and safely. It also comes with a very handy bag for keeping dirt out of the delicate mechanism of the rail - another nice touch!
this guy was absolutely tiny, but the rail handled the small steps with no trouble
I would encourage you to check out the video (below) to learn more about the way I use the rail and to get the details on how to add an indexing pin to make precision micro-stepping a piece of cake.
Let me know if you have any questions, and get one of these rails - you will be glad you did (especially when your Stackshot breaks down!).