Takahashi Epsilon-180ED 1.5x Extender

Product Overview

The Epsilon Extender 1.5x E-180ED extends the Epsilon-180ED astrograph's native 500mm f/2.8 to 780mm f/4.3, carrying the Epsilon series' coma correction through to the longer focal length. Seven elements in five groups magnify and re-correct the image together, holding the same fully-corrected Φ44mm circle the telescope delivers at prime focus.

Who It's For

This extender suits Epsilon-180ED owners who want more reach for tighter deep-sky targets — galaxies, planetary nebulae, compact clusters — while keeping the fast, coma-corrected imaging the Epsilon-180ED is built for.

Key Features & Design

• 7 elements in 5 groups: a complete optical assembly that maintains coma correction at the extended focal length.
• 1.5x extension: takes the Epsilon-180ED from 500mm f/2.8 to 780mm f/4.3.
• Φ44mm corrected image circle: fully corrected for coma, suited to full-frame sensors.
• M68 input / M54 output threads: installs between the Epsilon-180ED's camera angle adjuster and a standard camera adapter.

Optical / Mechanical Design

Back focus with the extender in place is 56.2mm, the same figure the Epsilon-180ED uses at prime focus, so an existing spacing setup carries over directly. See the Takahashi Back Focus Guide for the full spacing chain.

Recommended Uses

Imaging smaller deep-sky targets that are undersized in the Epsilon-180ED's native 500mm field; narrowband and high-resolution imaging where the extra reach helps frame a target tightly; general astrophotography where 780mm f/4.3 suits the target better than 500mm f/2.8.

Compatibility and Accessory Notes

The extender is specific to the Epsilon-180ED — the Epsilon-130D and Epsilon-160ED each use their own dedicated 1.5x extender, sized for their own thread interfaces.

Good to Know Before You Order

Filters mount at the camera, not on the extender: Takahashi recommends against screw-in 2" filters here, so a filter wheel or camera-side filter mount is the way to add narrowband or broadband filtration.

At 550g, it's a modest addition to the imaging train — worth noting once your camera and filter wheel are attached, but not a figure that will drive your balance point on its own.

Frequently Asked Questions

Is it difficult to set up?

No — it installs between the Epsilon-180ED's camera angle adjuster and your camera on M68 and M54 threads, and the 56.2mm back focus matches the telescope's native prime-focus figure.

What is it best used for?

Imaging deep-sky targets that need more reach than the Epsilon-180ED's native 500mm provides, while keeping the coma correction the Epsilon series is known for.

Does it work for visual observing?

It's built as an imaging accessory — the corrected image circle and mechanical interfaces are designed around camera sensors rather than eyepieces.

What else do I need with it?

Your camera's own T-ring or M54 adapter to complete the connection at the 56.2mm back focus figure.

Bottom Line

A coma-corrected 1.5x extender that takes the Epsilon-180ED to 780mm at f/4.3 across a Φ44mm image circle, at the same 56.2mm back focus the telescope already uses at prime focus.