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Extension tubes

Omegon 2 in extension sleeve, 50 mm optical path (55072)

A 2 in extension sleeve of 50 mm optical path with a spring-ring clamp, a filter thread at the lower end and internal ribbing against reflections.

Omegon 2 inch extension sleeve with spring-ring clamp

Omegon 2 in extension sleeve, 50 mm optical path (55072)

A 2 in extension sleeve of 50 mm optical path with a spring-ring clamp, a filter thread at the lower end and internal ribbing against reflections.

Length
50 mm, as the maker publishes it
Barrel and thread fittings
2 in · 2 in, at the lower end
Internal blackening
Ribbed inside against reflections, black anodised outside
Clamping method
2 in spring-ring clamp, per the maker
Rigidity
Not published by the maker.
Material
Not published by the maker.
Amazon reference
B074FQH48F (same reference on 6 Amazon marketplaces)
EAN
4049467550723
  • Publishes the optical path added, which is the only figure that matters for an extension
  • A spring-ring clamp grips the barrel evenly instead of denting it with a screw
  • Fifty millimetres is a large step; finer adjustment needs a set of thin rings

Best for: A telescope whose focal plane sits too far out for its eyepieces to reach

≈ £36 / €39
Check price on Amazon

Specifications

Length
50 mm, as the maker publishes it
Barrel and thread fittings
2 in · 2 in, at the lower end
Internal blackening
Ribbed inside against reflections, black anodised outside
Clamping method
2 in spring-ring clamp, per the maker
Rigidity
Not published by the maker.
Material
Not published by the maker.
Amazon reference
B074FQH48F (same reference on 6 Amazon marketplaces)
EAN
4049467550723

Fifty millimetres, published

The optical path an extension adds is its whole specification, and Omegon prints it. Without that figure an extension is a guess, and with it the back focus budget can simply be added up.

The problem it exists to solve

Telescopes designed with photography in mind place the focal plane further out. That leaves room for a camera and its adapters — and it can put the focus beyond where an eyepiece can reach. A sleeve of known length restores it without moving anything else.

The clamp and the bore

A spring ring rather than a thumbscrew, and internal ribbing rather than paint. The first keeps the accessory centred and unmarked; the second breaks up light that would otherwise reflect off a smooth bore into the image.

And a filter thread

Two inches, at the lower end. A filter can live in the sleeve instead of being screwed to each eyepiece in turn, which is one fewer thing to do in the dark.

Availability

German, French, Italian and Spanish Amazon stores ran from 39 € to 42 € on the day of the survey.

British Amazon store lists it in local currency, which the euro range above sets aside.

American Amazon catalogue holds a record for it that nobody is selling.

Figures as Keepa reported them on the day this page was last updated. Stock and pricing shift without warning.

Prices quoted in this text were read on 17 September 2026. The live price is at the top of the page.

What this fits

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    Barrel and thread fittings
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    Internal blackening
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    Clamping method
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    Rigidity
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    Material
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    Length
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    Barrel and thread fittings
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    Internal blackening
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    • Brass tips under the thumbscrews prevent an inserted barrel being marked
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    Length
    Not published by the maker.
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    Internal blackening
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The rest of this rack

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    A thread adapter — no optics, and not a filter wheel
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    Power
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    Software support
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    Light sealing
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    Power
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    Software support
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    Software support
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