Takahashi TOA-150 / TSA-120 0.7x TOA-35 Reducer and Camera Ring

Product Overview

The TOA-35 Reducer 150 Set pairs Takahashi's 0.7x TOA-35 reducer with a CA Ring 150 sized for the TOA-150B and TSA-120/TSA-102, cutting these telescopes to a materially faster focal ratio while holding a flat Φ44mm image circle. The reducer is the same 4-element, 3-group ED glass optic used across the whole TOA-35 line — this kit's CA Ring 150 is what makes it fit the TOA-150 and TSA-120 mounts specifically, and it's the reason a camera ring is called out explicitly in this listing's title.

Who It's For

This kit suits TOA-150B and TSA-120 (and TSA-102) owners who want a faster imaging focal ratio without leaving the ED apochromat optics those telescopes are built around. On the TOA-150B it lands at f/5.2; on the TSA-120 at f/5.3 — both a substantial step down from their native focal ratios.

Key Features & Design

• 4 elements in 3 groups, ED glass: the same optical design used across every TOA-35 reducer kit.
• 0.7x reduction: cuts focal length on each compatible telescope to roughly 0.7x native.
• Φ44mm corrected image circle: flat, sharp field across the reduced focal length.
• Bundled CA Ring 150 ("camera ring"): sized for the TOA-150B and TSA-120/TSA-102 mounts, installed as a matched system rather than sourced separately.

Optical / Mechanical Design

The reducer threads to the included CA Ring 150. Back focus is 62.5mm on both the TOA-150B and the TSA-120. See the Takahashi Back Focus Guide for the full spacing chain.

Recommended Uses

Faster deep-sky imaging on the TOA-150B or TSA-120 where exposure time matters — nebulae, galaxies, and clusters that benefit from the reduced focal ratio; general astrophotography where a shorter focal length better frames larger targets.

Compatibility and Accessory Notes

This is the same 0.7x reducer optic used on the TOA-130, but bundled here with the larger CA Ring 150 for the TOA-150 and TSA-120/TSA-102 mounts. TOA-130NS/NFB owners use the sibling kit, the TOA-35 0.7x Reducer for TOA-130, which bundles the identical reducer with CA Ring 130 instead — the two kits are not interchangeable between telescopes even though the optic inside them is the same.

Good to Know Before You Order

Sold as a matched kit: the CA Ring 150 (the "camera ring" in this listing's title) is bundled with the reducer, so there's nothing separate to source for a TOA-150B or TSA-120.

Frequently Asked Questions

Is it difficult to set up?

No — the reducer threads to the included CA Ring 150, sized to install directly on either telescope's mount.

What is it best used for?

Deep-sky astrophotography on the TOA-150B or TSA-120 at a faster focal ratio than either telescope's native configuration.

Is this the same reducer as the TOA-130 kit?

The optic is identical. What differs is the bundled ring — this kit ships with CA Ring 150 for the TOA-150/TSA-120; the TOA-130 kit ships with CA Ring 130 instead.

What else do I need with it?

Your camera's own T-ring or adapter to complete the connection at the 62.5mm back focus figure.

Bottom Line

A matched TOA-35 reducer kit for the TOA-150B and TSA-120/TSA-102, with the CA Ring 150 camera ring included, delivering a flat Φ44mm image circle at f/5.2-5.3.