• Line art displaying a nrStellar customized ring kit
  • A nrStellar customized ring kit holding a lens. There is a finderscope shoe and a ZWO electronic autofocuser attachment.
  • nrStellar Ring System with a ZWO EAF turning the focus ring on a camera lens
  • A nrStellar customized ring kit holding a lens. There is a finderscope shoe, ZWO electronic autofocuser attachment, and an accessory plate holding a powerbox or mini PC. The rings are black with white text reading "nrStellar"
  • Technical diagram showing some of the necessary measurements to order a nrStellar customized ring kit. The measurements are: 1. Front Ring Diameter 2. Rear Ring Diameter 3. Distance Between Ring Centers and 4. Ring Thickness
  • Technical diagram showing some of the necessary measurements to order a nrStellar customized ring kit. The measurements are: 1. Distance from the Front Ring to the Helical Focuser Gear 2. Diameter of the Helical Focuser
  • Two hexagonal nrStellar lens rings side-by-side. The left one is skinnier than the right one. The left one is labeled "Thin" and the right one is labeled "Extra Thick". The rings are black with white text that reads "nrStellar". An arrow and text that reads "Foam Lined" points at the foam lining on the inside of the rings.
  • Findershoe bracket for the nrStellar Rokinon Ring System. One arrow with text reads "Fits Your Guidescope, Red Dot Finders, and Other Synta-Style Accessories". Another arrow with text points to the embedded nuts, noting that they cannot be pulled out.
  • ZWO EAF adapter kit for the nrStellar Rokinon Ring System. Text with arrows points out the "18-8 Stainless Steel Hardware" and the "Geared Autofocus Allows Easy Rotation"
  • an nrStellar Camera Ring standing up against a white background. It is black. Text reads "Stainless Steel Embedded Nuts", with an arrow pointing to a nut embedded in the 3D printed ring.
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Customized Ring Kit for Any Lens

Customized Ring Kit for Any Lens

$58.99
$58.99
Sale Sold out

We've taken our experience with rings for the Rokinon/Samyang 135 f/2 lens and created a system that can be adapted to just about any camera lens or small/medium telescope. With the same modular design, you can attach a ZWO electronic autofocuser, guidescope, mini PC, ASIAir, and other accessories. 

Features:

  • Material: Thick-walled, carbon fiber-infused PETG with stainless steel fasteners. Our custom blend of carbon fiber PETG performs better than commercially available PETG-CF blends. 
  • Modularity: Interchangeable accessory plates allow you to mix, match, and rearrange gear to suit your setup.
  • Lens Grip: Weather-resistant EPDM foam lining securely grips your lens.
  • Geared ZWO Electronic Autofocuser Adapter: Allows for easy lens rotation and precise, backlash-free autofocus. 
    • Comes with gears for both the old ZWO EAF and the new ZWO EAF-N and EAF Pro.
  • Accessory Mounting:
    • Universal Findershoe Saddle: Holds a guidescope, ASIAir, and other items with a finderscope dovetail.
    • General-Purpose Accessory Rail: Allows you to bolt on accessories like a powerbox or mini PC. Also serves as a flat surface to apply adhesive-backed Velcro to, should you wish to attach components that can't be bolted on.
  • Ring Sizes:
    • Standard Width: 15mm (for most lenses).
    • Extra Thick: 30mm (for heavy lenses and added rigidity).
  • Robust Hinge: Double-shear hinge design prevents bolts from backing out over time.
  • Compatibility: Fits most lenses and small/medium telescopes from all brands -- Canon, Nikon, Sigma, Rokinon/Samyang, Askar, SVBONY, and more.

We highly recommend using a pair of calipers to measure your lens. A cheap pair of calipers is a great tool to have in this hobby. Do not round the numbers you measure with your calipers.

All nrStellar products come with a 2 year warranty. If you experience any issues, just shoot us an email and we’ll sort you out.
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Customer Reviews

Based on 1 review
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Norman Hey
Rings available for Canon EF 100-400mm f/4.5 L IS II lens!

Custom mounting rings for Canon EF 100-400mm f/4.5-5.6 L IS II USM lens

TLDR: if you have this lens and want to use it for astrophotography, get this ring set and EAF bracket and gear set. Best thing you can do!

I have been using this lens coupled to a QHY168c for a year or so. Originally purchased for bird photography, I was very pleasantly surprised by how well it works as an astrophotography tool. My AstroBin gallery has several examples. The variable focal length makes framing targets just the way you want them very simple and even used wide open at f/4.5 the stars are not horribly distorted. A pass through BlurXterminator on correct-only mode makes them just about perfect! The lens holds focus well at all focal lengths, but needing to focus with a Bahtinov mask is a significant drawback, once you have enjoyed electronically assisted focusing. The biggest attraction of this ring system is the incorporation of an EAF bracket and gear system. I contacted Noah at nrStellar about making rings for this lens. After sending in measurements and photos, Noah created a cutout to accomodate the foot pad and the rotating collar lick knob as well as customizing the ring spacing and focusing ring gear system. Once we confirmed all the measurements, he printed and shipped it all and I had it in hand in days.

Assembly was simple and straightforward and the fit was perfect for the rotating collar in terms of spacing, but I needed to put a thin shim of material under the upper part of that ring to ensure a completely rigid mount. I don't think that there would be any movement without the shim, but there is definitely no movement with it in place. Noah has printed a new upper rear ring that reduces this space, but a small shim is still required as before. I suspect that I could easily get away without it, but it is such a simple fix, I will keep it. The attached image shows the cutout for the collar foot and rotation lock knob. Two accessory mounting plates are in use, one for the Quieter3c and one for the SV210 power distribution box. Gude scope mounting shoe and the EAF mounting bracket can be seen, but the focus ring gear is not seen in this view.

Using a ZWO EAF, the mounting bracket and gear system works just as expected. Wrapping the focus ring gear onto the lens' focus ring is simple and secure and the gears mesh easily and securely. I tested it with the manual controller in daylight and it worked perfectly. Under the stars, I was able to work out a step size quite quickly using NINA. The critical focus zone of my version of this lens is fairly broad, making selecting a step size that works well a bit of a challenge, especially for dualband filters and their longer exposures, and using autofocus is therefore still a work in progress. However, it is easy to get to optimum focus with a few iterations and because the lens holds focus so well, with little noticeable effect of changing temperature so far, this doesn't seem to be a big issue.

With its wide range of focal lenght choices, it will make your widefield imaging of just about any target easier than you could ever hope for. You will read lots of opinions claiming zooms can't hold a candle to prime lenses when used for astrophotography. Well, this is an awfully good zoom right off the hop, and even without using RC AStro's BlurXterminator it captures very good images. Just about everyone uses BXT now anyway even with premium imaging setups--it's a no-brainer. Adding the capability of focusing from a remote connection is also a no-brainer. See my AstroBin page for some examples of images created with this lens using nrStellar mounting ring system!

At the price and with the quality of the product and customer service, I highly recommend this mounting system for the Canon EF 100-400mm L IS II lens.

Norman Hey
Sudbury, ON
Canada

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Total Price:
$58.99