Explore Scientific FCD100 127mm f/7.5 Triplet APO Refractor Telescope

The Explore Scientific FCD100 127mm APO delivers the same premium HOYA FCD100 optics found in refractors costing $3,000–$5,000, in a proven aluminum optical tube at a fraction of the price. This air-spaced triplet design achieves 0.91 arcsecond resolution with virtually zero chromatic aberration — performance that Cloudy Nights reviewers have called "neck and neck" with an Astro-Physics Starfire. At 952mm focal length and f/7.5, it's equally at home on planets and deep-sky targets.

Key Features

• HOYA FCD100 Extra-Low Dispersion Glass – FPL-53 equivalent optics virtually eliminate false color, delivering pinpoint stars and true-to-life colors in both visual and imaging use
• Air-Spaced Triplet APO Design – Three-element optical system achieves diffraction-limited performance with 0.91 arcsecond resolution and high contrast across the field
• Durable Aluminum Optical Tube – Classic white-finish aluminum construction provides a rigid, reliable platform for both permanent observatory setups and field use
• 2.5" Hexagonal Dual-Speed Focuser – Rock-solid rack-and-pinion design with 10:1 fine focus supports up to 10 lbs of imaging gear with zero flex or image shift
• EMD Enhanced Multi-Layer Coatings – Proprietary broadband coatings maximize light transmission and contrast for faint deep-sky targets
• Versatile f/7.5 Focal Ratio – Long enough for high-magnification planetary detail, yet pairs beautifully with the 0.7x reducer for faster deep-sky imaging at f/5.25
• Retractable Dew Shield – Blocks stray light and slows dew formation during extended sessions
• 99% Reflective 2" Diagonal Included – Premium dielectric diagonal maximizes light throughput right out of the box

Ideal For

• Serious visual observers stepping up from doublets or entry-level triplets who want pinpoint stars, jet-black backgrounds, and zero false color on planets and double stars
• Astrophotographers who need tight, round stars across the field and a focuser that won't flex under the weight of a dedicated astronomy camera, filter wheel, and auto-guider
• Observatory and backyard setups where the telescope lives on a permanent or semi-permanent mount — the aluminum tube's added weight is a non-issue when you're not hauling gear, and its rigidity is an asset
• Upgraders from 80–102mm APOs looking for a meaningful jump in aperture and resolution — the 127mm aperture collects 56% more light than a 102mm and delivers noticeably finer detail

Accessories & Compatibility

• Explore Scientific 3" Field Flattener & 0.7x Focal Reducer – Corrects field curvature and reduces focal length to f/5.25 for faster deep-sky imaging with sharp, flat stars edge-to-edge
• Explore Scientific 8x50 Illuminated Right Angle Polar Finder – Accurate polar alignment with an illuminated reticle for precise tracking during long exposures
• Explore Scientific EXOS2-GT Equatorial Mount – GoTo motorized mount with PMC-Eight system for automated object tracking and long-exposure astrophotography
• Explore Scientific Soft-Sided Telescope Case – Padded protection for safe transport to dark-sky sites

Looking for the lightweight option? The FCD100 127mm Carbon Fiber version shares the same optics and focuser in a carbon fiber tube that's 4 pounds lighter with superior thermal stability — ideal for portable setups and travel.

Note: A finder scope and carrying case are not included. The pre-installed 2N1 finder scope base accepts most standard finder scopes and guiding systems.