Takahashi FC-76DP 0.64x FU Reducer

Product Overview

The FC-76DP 0.64x FU Reducer is Takahashi's dedicated fluorite focal reducer for the FC-76DP refractor. It brings the telescope's native 570mm f/7.5 down to 365mm at f/4.8, using fluorite elements to keep chromatic error under control at this level of reduction.

Who It's For

This reducer suits FC-76DP owners who image both wide fields and tighter deep-sky targets and want a faster focal ratio without giving up the telescope's sharp, high-contrast optics. Takahashi's own spot-radius figures for this combination run about 1.5 microns across APS-C and under 2 microns even at the edge of full frame.

Key Features & Design

• Fluorite reducer elements: hold chromatic error in check through the 0.64x reduction.
• 0.64x reduction: takes the FC-76DP from 570mm f/7.5 to 365mm f/4.8.
• Φ44mm corrected image circle: covers APS-C fully, with strong performance well into full-frame corners.
• M55.9 thread mount: installs directly into the FC-76DP drawtube system.

Optical / Mechanical Design

The reducer pairs with the included CA-35 (FURD) spacing ring, which sets a fixed back focus of 56.0mm measured from the rear of the adapter. That figure — not the telescope's native focal plane — is the one to build an imaging train from. See the Takahashi Back Focus Guide for the full spacing chain.

Recommended Uses

Deep-sky imaging of nebulae, clusters, and galaxies at a fast f/4.8; full-frame astrophotography where the wide, well-corrected image circle counts; general FC-76DP imaging where shorter exposures are worth the reduced focal length.

Compatibility and Accessory Notes

The CA-35 (FURD) spacing ring ships with the reducer and fixes the 56.0mm figure above. Camera-side spacing from there follows your camera's own flange distance — full detail in the Takahashi Back Focus Guide.

Good to Know Before You Order

Built specifically for the FC-76DP: these figures don't carry over to the FC-76DCU or other FC siblings, which use their own reducers.

Frequently Asked Questions

Is it difficult to set up?

No — it threads into the FC-76DP drawtube with the included CA-35 spacing ring, and the 56.0mm back focus figure is fixed by that ring.

What is it best used for?

Deep-sky astrophotography on the FC-76DP at a fast f/4.8, across both APS-C and full-frame sensors.

Does it work for visual observing?

No — it's built for a flat photographic image circle rather than a visual eyepiece path.

What else do I need with it?

The CA-35 (FURD) spacing ring, included with the reducer, and your camera's own T-ring or adapter to complete the 56.0mm back focus.

Bottom Line

A dedicated fluorite reducer that takes the FC-76DP to 365mm at f/4.8 with a flat Φ44mm image circle, set up with the included CA-35 ring at a fixed 56.0mm back focus.