Questions about the Astrodymium Ring System

No, sorry.

It takes significant time to design, prototype, validate, and manufacture a ring system for a new scope/lens (at minimum dozens of hours).
It also would require me to have a copy of the lens on hand to make sure everything works as intended.

The reasons above make it not possible for custom ring systems to be made.

Officially the ring system is only supported with the Rokinon/Samyang 135mm F/2 lens (and the T2.2 cine version).

However, if your lens has diameters smaller than 70mm, then it may be possible to modify it to fit the rings that clamp onto the lens.

It may be possible to wrap tape or any kind of padding to fit the diameter of the front and rear ring.

Front ring inner diameter: 80mm
Rear ring inner diameter: 70mm
Center to center distance between front and rear rings: 83mm

Yes, the ring system is compatible with the CINE version of the Rokinon/Samyang 135mm.

However, if you are purchasing the ZWO EAF mount then you will need a slightly different part for it to work with the CINE version.

After you place your order, please contact me (you can reply to the order confirmation email) and say that you are purchasing for the CINE lens, so I can make sure that I send you the correct part.


Many lenses do not work with the ring system idea, due to geometry reasons (focusing changes the length, shape is too short for the rings, etc).

Any dovetail bar that is flat on top, and has slots for the holes will work with the ring system.

M6 screws for connecting the rings to a dovetail bar are included with all configurations.


- Astrodymium Vixen & Arca-Swiss Dovetail Bar for Ring System
- William Optics DSD 210 Plate
- Astro Essentials Short (18cm) Dovetail
- Askar Vixen-Style Universal Dovetail Plate

No. The ZWO EAF (12/5v) is the only compatible autofocuser that will work with the ring system.

The EAF adapter will also not work with other mounting systems (like the RedCat 51 ring). You must purchase the entire ring system to get autofocus.

It is also not possible to make the EAF adapter add-on work by itself with other lenses.

The EAF adapter does not work by itself, and is not a standalone product. It is only designed to be used with the ring system.

It is not possible to modify it to work for other lenses.

Questions about shipping

Visit the shipping policy page:

Canada: Sales tax is collected at checkout

United States: No tax.

International: Import laws vary significantly between countries. You will have to consult reputable sources on whether your country collects taxes/duties when importing goods.

Unfortunately I cannot undervalue the cost of orders.

Please note that UPS will charge a brokerage fee of $10-$15 if they have to collect tax (there is no extra charge if your country does not collect tax on imports such as the U.S).

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