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Optical Tube Assemblies

Optical tube assemblies, commonly abbreviated by astronomers as OTAs are simply the tube of the telescope where the optics are internally located. OTAs can be helpful in a situation in which an observer has a compatible mount and doesn't want to buy a whole new telescope with a mount included. Optical Tube Assemblies can come in the form of Maksutov-Cassegrain, Astrographs, Reflectors, Refractors, Schmidt-Cassegrains and many others! With the right mounting connections and range of mount and tripod payload, OTAs are a great choice for changing optical type without changing the mount.

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  1.  Borg - 77 ED II f/4.3 Astrograph Set (2178 + 7135 + 7835 + 7704)

    Borg - 77 ED II f/4.3 Astrograph Set (2178 + 7135 + 7835 + 7704)

    • BORG 77EDII OTA
    • 0.65x reducer
    • Total of 6 elements
    • 330mm focal length
    • F4.3
    • 35mm full-frame coverage
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    (48 States)
    Model#: B07743
    $2,175.00

  2.  Takahashi - TOA-150B Refractor Optical Tube Assembly - Heavy-Duty 4" Focuser

    Takahashi - TOA-150B Refractor Optical Tube Assembly - Heavy-Duty 4" Focuser

    The TOA-150 is the second Takahashi Ortho Apochromat to be developed by Takahashi. It features a newly designed triplet objective. This new design like its smaller companion the TOA-130 is absolutely color free

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    (48 States)
    Model#: TOK1501
    $11,400.00

  3. AG Optical 12.5" Imaging Harmer Wynne Astrograph

    AG Optical - 12.5" Imaging Harmer Wynne Astrograph

    Imaging Harmer Wynne (iHW) astrographs are high resolution, fast focal ratio instruments with excellent on and off axis performance.

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    (48 States)
    Model#: iHW12.5
    $15,775.00

  4. AG Optical 14" Imaging Harmer Wynne Astrograph

    AG Optical - 14" Imaging Harmer Wynne Astrograph

    Imaging Harmer Wynne (iHW) astrographs are high resolution, fast focal ratio instruments with excellent on and off axis performance.

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    (48 States)
    Model#: iHW14
    $23,975.00

  5. AG Optical 16" Imaging Harmer Wynne Astrograph

    AG Optical - 16" Imaging Harmer Wynne Astrograph

    Imaging Harmer Wynne (iHW) astrographs are high resolution, fast focal ratio instruments with excellent on and off axis performance.

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    (48 States)
    Model#: iHW16
    $27,595.00

  6. ASA - 200mm Hyperbolic Astrograph

    ASA - 200mm Hyperbolic Astrograph

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    Model#: 8HSOK3ZK
    $11,235.00

  7. Astro-Tech Black 72mm f/6 ED Doublet Refractor OTA

    Astro-Tech - Black 72mm f/6 ED Doublet Refractor OTA

    Astro-Tech has built this optical tube by increasing their previous aperture of 66mm to a now 72mm. This allows 9% higher resolution and 19% better light gathering. In addition, a new and updated focuser has been supplied with this telescope.

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    (48 States)
    Model#: AT72BK
    $379.00

  8. Astro-Tech - Blue 72mm f/6 ED Doublet Refractor Optical Tube Assembly

    Astro-Tech - Blue 72mm f/6 ED Doublet Refractor Optical Tube Assembly

    Astronomy magazine called this scope’s predecessor, the 66mm Astro-Tech AT66ED, “a product everyone should own.”

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    (48 States)
    Model#: AT72BL
    $379.00

  9. Astro-Tech Green 72mm f/6 ED Doublet Refractor Optical Tube Assembly

    Astro-Tech - Green 72mm f/6 ED Doublet Refractor Optical Tube Assembly

    This green optical tube from Astro-Tech is a piece of equipment every advanced serious astronomer should consider. With high quality refractive optics, fabulous accessories, it is pretty amazing.

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    (48 States)
    Model#: AT72GR
    $379.00

  10. Astro-Tech - Red 72mm f/6 ED Doublet Refractor Optical Tube Assembly

    DISCONTINUED: Astro-Tech - Red 72mm f/6 ED Doublet Refractor Optical Tube Assembly

    This is a discontinued item. We recommend the Astro-Tech White 72mm Refractor or Black 72mm Refractor as replacements.

    Astronomy magazine called this scope’s predecessor, the 66mm Astro-Tech AT66ED, “a product everyone should own.”

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    (48 States)
    Model#: AT72R
  11. Astro-Tech - White 72mm f/6 ED Doublet Refractor Optical Tube Assembly

    Astro-Tech - White 72mm f/6 ED Doublet Refractor Optical Tube Assembly

    Astronomy magazine called this scope’s predecessor, the 66mm Astro-Tech AT66ED, “a product everyone should own.”

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    (48 States)
    Model#: AT72WH
    $379.00

  12. Borg - 125 SD f/3.9 Astrograph Set (9125S + 7835 + 7704)
  13. Borg - 125 SD f/6.5 Astrograph Set (9125 + 7835 + 7108)
  14. Borg 125SD 125mm f/6 Optical Tube Assembly

    DISCONTINUED: Borg - 125SD 125mm f/6 Optical Tube Assembly

    This is a discontinued item. We recommend the Explore Scientific ED127 Classic White "Essential Series" Air Triplet Apochromatic Telescope as a replacement.

    Featuring a collaboration between Borg and Pentax on a new objective design.

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    (48 States)
    Model#: 9125
  15. Borg - 45 ED II f/5 Astrograph Set (6045 + 7857 + 7885)

    Borg - 45 ED II f/5 Astrograph Set (6045 + 7857 + 7885)

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    FREE SHIPPING
    (48 States)
    Model#: B04561
    $850.00

  16. Borg 50mm F5 Achromat

    Borg - 50mm F5 Achromat

    Mini Borg scopes may be mounted directly with a 1/4"-20 threaded screw into the standard mounting block (left), or in an available finder bracket.

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    (48 States)
    Model#: 6150
    $215.00

  17. Borg - 60mm ED f/5.4 (325mm FL) Achromat

    Borg - 60mm ED f/5.4 (325mm FL) Achromat

    Mini Borg scopes may be mounted directly with a 1/4"-20 threaded screw into the standard mounting block (left), or in an available finder bracket.

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    (48 States)
    Model#: 6161
    $299.00

  18. Borg - 60mm ED f/5.8 (350mm FL) Optical Tube

    Borg - 60mm ED f/5.8 (350mm FL) Optical Tube

    Mini Borg scopes may be mounted directly with a 1/4"-20 threaded screw into the standard mounting block (left), or in an available finder bracket.

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    (48 States)
    Model#: 6260
    $575.00

  19. Tripod is NOT included!!!!

    Borg - 71FL Fluorite Optical Tube - Astro Visual Set

    Astro Visual set for the Borg 71FL Fluorite Optical Tube.

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    (48 States)
    Model#: 6272
    $1,175.00

  20. Camera is NOT Included!!!

    Borg - 71FL Fluorite Optical Tube - Basic Set

    Basic set for the Borg 71FL Fluorite Optical Tube.

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    (48 States)
    Model#: 6071
    $1,150.00

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