Explore Scientific AR127mm Achromatic Refractor OTA

Explore Scientific AR127mm Achromatic Refractor OTA

Due to high demand and global product shortages due to the pandemic, please call for availability.

The AR127 (five-inch) model, is a classic air-spaced, crown-and-flint doublet achromatic refractor. Our goal was to provide an extreme value by providing true diffraction-limited optics at a price that will allow more people to explore the sky with a wide-field (f/6.5) large aperture refractor. Images of deep sky objects are stunning at low to moderate magnification, and all at a small fraction of the price you would pay for a similar aperture apochromat refractor.

The dual speed 2" focuser featuring compression rings make focusing easy without blemishing the eyepiece tubes. The 2" 99% dielectric diagonal also ensures minimal contrast lost, maintaining the telescope's bright and crisp images.

Constructed using heavy-duty, high-quality parts, this telescope is well suited for the demands of public outreach. The cradle ring assembly with a built-on Vixen style dovetail and carry handle simplify transportation and ensure the telescope will be solidly mounted.


  • Air-spaced doubled
  • 2" 10:1 dual-speed focuser
  • 2" dielectric star diagonal
  • Compression rings throughout
  • Vixen style dovetail mount


  • Aperture: 127mm (5")
  • Focal Length: 826mm
  • Focal Ratio: f/6.5
  • Lens Construction: Achromatic Air Spaced Doublet
  • Focuser: 2" dual-speed focuser w/ compression rings
  • Diagonal: 2" dielectric 99% star diagonal w/ 1.25" reducer adapter, both w/ compression rings
  • Finderscope: 8x50mm straight-through
  • Eyepieces: sold separately, accepts 1.25" and 2" format
  • Camera Capable:
    • USB imagers
    • All-in-one cameras via universal digital camera adapter
    • DSLR/SLR (Requires T2 ring, 2" prime focus adapter)
    • Above cameras and adapters sold separately
  • Length (w/ dew shield): 863mm (34")
  • Diameter: 130mm (5.1")
  • Weight: 7.1kg (15.6lb)
  • Colour: white
  • Warranty: limited one year, upgradable to an extended warranty with registration