Explore Scientific ED127 127mm f/7.5 Triplet APO Refractor Telescope

Explore Scientific ED127 127mm f/7.5 Triplet APO Refractor TelescopeA 5 inch triplet APO refractor has traditionally been a $3,000+ investment putting premium refractor performance out of reach for observers who want serious aperture without serious chromatic aberration. The Explore Scientific ED127 Essential Series delivers 127mm of true apochromatic optics at a price point that makes triplet refractor performance accessible to serious observers and astrophotographers who would otherwise need to compromise on

A 5-inch triplet APO refractor has traditionally been a $3,000+ investment — putting premium refractor performance out of reach for observers who want serious aperture without serious chromatic aberration. The Explore Scientific ED127 Essential Series delivers 127mm of true apochromatic optics at a price point that makes triplet refractor performance accessible to serious observers and astrophotographers who would otherwise need to compromise on aperture or glass quality.

Key Features

• 127mm HOYA FCD1 ED glass triplet — air-spaced apochromatic design with EMD enhanced multi-layer coatings virtually eliminates chromatic aberration for true-color views of planets, double stars, and deep-sky objects
• Dual-speed 2" rack-and-pinion focuser — 10:1 fine-focus ratio with heavy-duty locks prevents drift under heavy imaging payloads; drawtube marked in cm and 1mm increments for repeatable focus positions
• Adjustable front lens cell — push-pull collimation screws allow precise optical alignment for pinpoint stars, a feature rarely found at this price point
• 0.91 arcsecond resolution — resolves tight double stars, Jupiter's cloud belt detail, and Saturn's Cassini Division at the theoretical limit for 127mm
• Retractable dew shield — shortens tube from 41.75" to 33.25" for compact transport without removing any components
• Vixen-style dovetail and cradle rings — universally compatible with most equatorial mounts; integrated handle doubles as a 1/4"-20 DSLR piggyback mount for wide-field imaging alongside your main camera
• Two 2" drawtube extensions included — adjust backfocus distance for compatibility with a wide range of eyepieces and camera setups

Ideal For

• Intermediate astrophotographers upgrading from an achromat or reflector — the ED127 eliminates the false color and diffraction spikes that compromise long-exposure images, and the locked dual-speed focuser holds critical focus through multi-hour sessions
• Visual observers who want a refractor that shows planets and double stars with textbook-sharp Airy discs and clean color — the adjustable collimation lets you dial in perfect star shapes
• Portable setups — at 18 lbs the OTA pairs well with mid-range mounts like the Explore Scientific EXOS2-GT PMC-Eight and the retractable dew shield makes it easy to fit in the Explore Scientific Soft-Sided Case

Accessories & Compatibility

The ED127 ships with a 99% reflective 2" dielectric star diagonal, a hybrid 2N1 finder scope base (finder sold separately), dual split cradle rings with Vixen-style dovetail, retractable dew shield with dust covers, and two 2" drawtube extensions for backfocus adjustment.

For astrophotography, pair with the Explore Scientific 3" Field Flattener / 0.7x Focal Reducer to flatten the field across your sensor and reduce the effective focal ratio to f/5.25 for faster imaging. Add an 8x50 Illuminated Right Angle Finder for comfortable target acquisition without straining your neck.