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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.

Orion Optics UK Truss Shroud for 20″ Telescopes

by Orion Optics UK
SKU OOUK-ODK20TR-MS
$1,400.14 - $1,400.14
$1,400.14
$1,400.14 - $1,400.14
$1,400.14
Price Match Policy!
  • Designed for 20″ open-truss telescopes
  • Blocks stray light to dramatically increase image contrast
  • Specialized breathable material promotes thermal stability
  • Prevents distracting tube currents and heat plumes
  • Flexible fabric fits around focusers, finders, and dovetails
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Truss Shroud for 20″ Telescopes

    The Truss Shroud for 20″ Telescopes is an essential accessory designed to unlock the full contrast potential of your large-aperture instrument by eliminating stray light. Crafted from a specialized black, latex-type material, this shroud creates a completely dark optical path while maintaining the critical airflow needed for thermal equilibrium in a 20″ truss design.

    Maximize Contrast on Your 20″ Scope by Eliminating Stray Light

    An open truss design is excellent for portability and rapid cooling, but it leaves the optical path vulnerable to off-axis light from streetlights, moonlight, or even a bright laptop screen. This stray light reduces contrast, washing out faint details in galaxies and nebulae. This shroud provides a simple, effective solution by completely enclosing the truss poles, ensuring your eye or camera sees only the light from your intended target against a black sky.

    Engineered Airflow for a Thermally Stable 20″ Optical Path

    Unlike simple, non-breathable covers that can trap heat and create damaging tube currents, this shroud is made from a material specifically chosen for astronomy. It is engineered to allow air to flow freely through the fabric, helping your 20″ mirror reach and maintain ambient temperature. This thermal stability results in sharper, steadier views, especially during long imaging sessions or nights with dropping temperatures.

    Flexible Design for Custom Truss Coverage

    Every imaging setup is unique. This shroud's flexible, manipulative material allows you to achieve a custom fit around your specific configuration of accessories. You can easily stretch and position the fabric to cover gaps around dovetail plates, finderscopes, and the focuser assembly, creating a truly dark environment without interfering with your equipment.

  • What is the primary purpose of the Truss Shroud for a 20″ telescope?

    The primary purpose is to block stray light from entering the optical path of an open-truss telescope. This significantly increases image contrast, making it easier to see faint details in deep-sky objects and improving planetary observations.

    How does this Truss Shroud help with thermal management on a 20″ ODK?

    The shroud is made of a breathable, latex-type material that allows air to flow freely. This prevents the buildup of warm air inside the optical tube, which can cause "tube currents" that degrade image sharpness. It helps the 20" primary mirror and entire optical assembly remain at ambient temperature for more stable views.

    Is the material of the 20″ Truss Shroud waterproof?

    This shroud is designed primarily for light control and airflow, not for weatherproofing. While the latex-type material may offer some resistance to dew, it should not be considered waterproof. It is intended to be used during observing sessions, not as a permanent or protective cover against rain.

    Will this 20″ Truss Shroud fit around my focuser and filter wheel setup?

    Yes, the material is described as flexible and manipulative. This allows you to stretch and position it to create a snug fit around most common accessory configurations, including focusers, filter wheels, and finderscopes, ensuring no light leaks into the optical path.

    Why is a breathable shroud better than a solid tube for my 20″ truss Dobsonian?

    A solid tube can trap a column of air, which cools at a different rate than the outside air, creating persistent thermal currents that soften the image. A breathable shroud like this one for your 20" Dobsonian allows the telescope to equalize with the ambient temperature much more effectively, providing sharper and more stable views while still blocking stray light.

    How does using the 20″ Truss Shroud improve views of faint targets like the Horsehead Nebula (Barnard 33)?

    Extremely faint, low-contrast targets like the Horsehead Nebula are easily washed out by even minor light pollution or stray light. By creating a darker background sky, the 20" Truss Shroud increases the contrast between the nebula and its surroundings, making the faint dust lanes significantly easier to detect visually or to capture in an astrophoto.

    • Truss Shroud for 20″ Telescopes

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  • Orion Optics UK 1-Year Warranty