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All-Star Telescope is your source for all things astro from telescopes to astrophotography cameras. Have a question? We'd love to help. Email: Call Us: (587) 336-6621 Toll Free: 1 (866) 310-8844
Have a question? We'd love to help. Email: Call Us: (587) 336-6621 Toll Free: 1 (866) 310-8844

Orion EON 115mm ED Triplet Apochromatic Refractor Telescope (10285)

SKU 10285
Original price $2,209.99 - Original price $2,209.99
Original price
$2,209.99 - $2,209.99
Current price $2,209.99

Product is not in stock at the moment but we expect it to arrive soon.

New stock is arriving all the time. We will let you know an estimated timeline for when your reserved item will arrive.

With exceptional optics, top-notch features and beautiful fit and finish, the Orion EON 115mm ED Triplet refractor telescope offers wide-field observers and astrophotographers an impeccably crafted, true-colour instrument at a great price. We've updated the previous award-winning design with an even more robust focuser, and streamlined the tube rings and dovetail bar. From front to back, this is a beautifully well-crafted and rock solid design.


This premium refractor telescope's generous, 115mm (4.5") aperture collects ample light from faint deep-sky objects to provide crisp images with excellent colour correction by virtue of the element of FK-61 extra-low dispersion ("ED") optical glass in its air-spaced triplet objective lens. The apochromatic refractor's medium 805mm focal length gives it a fairly fast, f/7.0 f-ratio which performs exceptionally well for wide-field visual use or deep-sky astrophotography. Multilayer anti-reflection coatings on every air-to-glass lens surface maximizes light transmission; while an extendable dew shield, blackened lens edges, and multiple internal knife-edge baffles eliminate off-axis reflections and glare to ensure excellent contrast.

At the back end of the EON 115mm Triplet ED, you'll find a new heavy-duty 2.5" dual-speed Rack-and-pinion focuser with precise 10:1 fine focus control. The focuser features an Orion finder scope base for attachment of any Orion reflex sight or finder scope, if desired. The big focuser's 2.5" drawtube sports an engraved millimetre scale to aid in focus point repeatability, and features a focus-lock thumbscrew, both of which are especially useful for astrophotography. Both the 2" accessory collar on the focuser drawtube and the 1.25" adapter feature non-marring brass compression rings, and a robust "twist-lock" style mechanism for securely clamping down onto the diagonal or camera nosepiece.

Not only is the EON 115mm ED Refractor a great wide-field performer, it's also conveniently compact and measures just 28" with its sliding dew shield retracted for easy transport and storage in the included foam-lined hard carry case. Unlike heavier, bulkier astrophotography telescopes, the relatively lightweight, 15 lb. EON 115mm optical tube needs only a medium-sized equatorial mount to support it.

The EON 115mm refractor's finder dovetail base can also be used for optional guide scopes such as one of our Mini Guide Scopes. A slip-fit metal objective lens cap, a narrow "Vixen-style" dovetail mounting bar and two heavy-duty hinged tube rings with multiple, pre-drilled and tapped holes along the top and bottom are included.

If you're looking for an exquisitely constructed "apo" refractor that can achieve amazing results for both astrophotography and serious visual observing, the versatile Orion EON 115mm ED Triplet is an ideal choice.

Quick Overview

  • A beautifully constructed, 115mm (4.5") aperture triplet ED apochromat ideal for both astrophotography and serious visual observations
  • Fully multi-coated, three-lens ED optics and versatile f/7.0 focal ratio yields high-contrast images with excellent colour correction and sharpness
  • New and improved 2.5" dual-speed (10:1) Rack-and-pinion focuser provides precise focus control as well as strong lifting capability for heavy cameras and accessories
  • Includes two split-clamp tube rings and a triple-latch hard case for protection during transport and storage
  • Relatively lightweight 15 lb. optical tube can be stably supported by medium-size equatorial mounts

What's in the Box

  • 115mm ED Triplet optical tube assembly
  • Finder scope base (installed)
  • Narrow style dovetail mounting bar
  • Heavy-duty hinged tube rings (x2)
  • Foam-lined hard carry case
  • Dust caps


Best for viewing  Lunar & bright deep sky
Best for imaging Deep sky
User level Advanced
Optical design Refractor
Optical diameter 115mm
Focal length 805mm
Focal ratio f/7.0
Coatings Fully multi-coated
Optics type Air-spaced triplet
Glass material Extra low dispersion
Resolving power 1.00arc*sec
Lowest useful magnification 19x
Highest useful magnification 230x
Highest theoretical magnification 230x
Limiting stellar magnitude 13.0
Optical quality Diffraction limited
Finder scope 5x24
Focuser 2.5" dual-speed Rack-and-pinion
Mount type Optical Tube without Mount
Astro-imaging capability Lunar, planetary & terrestrial
Backfocus distance 158.0mm
Tube material Aluminum
Length of optical tube 28.0 in.
Weight, optical tube 15.0 lbs.
Additional included accessories Aluminum-clad hard case, Tube rings, Aluminum, slip-on objective lens cap
Other features Retractable dew shield, , Compression ring eyepiece clamp
Warranty One year