Takahashi Vari-Ring Spacer

Product Overview

The Vari-Ring Spacer is a Takahashi M72 x 1.0 ring built for one job on the TOA telescope series: shifting how much reduction the matched reducer actually delivers. Takahashi publishes its light path at 17 mm — add it ahead of a TOA reducer and the effective reduction ratio changes with it.

Who It's For

This is a good match if you're running a TOA-series reducer and want to fine-tune the reduction ratio, or you're matching a published system chart that calls for the Vari-Ring specifically.

Key Features & Design

• M72 x 1.0 thread on both ends: male on one side, female on the other, so it drops straight into the M72 reducer chain.
• 17 mm light path: enough to noticeably shift a TOA reducer's effective ratio without swapping the reducer itself.
• Takahashi part TKA31581 — Takahashi's own "Vari-Ring" designation.

Recommended Uses

Use it between a TOA-series reducer and the rest of the imaging train to shift the effective reduction ratio, per Takahashi's published system chart for your telescope.

Compatibility and Accessory Notes

It fits Takahashi's M72 x 1.0 accessory system used on the TOA series. The 17 mm figure is what it contributes to the optical train, not its physical length end to end — the male and female M72 threads seat differently than a caliper measurement would suggest. The Takahashi Back Focus Guide lists this figure next to the back focus target for each TOA model, so you can check the total spacing before ordering.

Frequently Asked Questions

Is it difficult to set up?

No — it threads into the M72 reducer chain like any other ring in the system.

What is it best used for?

Adjusting the effective reduction of a TOA-series reducer by changing the spacing ahead of it.

Does it work with reducers outside the TOA series?

Takahashi documents it for the TOA series specifically. If you're matching a different M72 reducer, send us your telescope and reducer model and we'll confirm the fit.

Bottom Line

An M72 x 1.0 spacer built to dial in the reduction on a TOA-series reducer, adding 17 mm to the optical train in the process.