Explore Scientific ED102-FCD100 102mm f/7 Carbon Fiber Air-Spaced Triplet Refractor with iEXOS-100-2 PMC-Eight GoTo Mount

Product Overview

This package pairs the Explore Scientific ED102-FCD100 with the iEXOS-100-2 PMC-Eight equatorial tracker system. The telescope is a 102 mm f/7 air-spaced apochromatic triplet using HOYA FCD-100 extra-low-dispersion glass in a carbon fibre tube, at 714 mm focal length and 9.5 lb. It arrives with a computerised GoTo mount, tripod, and counterweights.

Who It's For

This is the step up in aperture from the 80 mm triplets while staying genuinely portable — the carbon fibre tube is what makes that possible. It suits an imager who wants more resolution and a longer native focal length for galaxies and planetary nebulae, and a visual observer who wants a 4-inch apochromat that still travels easily.

Key Features & Design

• 102 mm f/7 air-spaced triplet with HOYA FCD-100 ED glass, 714 mm focal length
• Carbon fibre tube, holding weight to 9.5 lb and reducing focus shift as temperature drops
• 45 mm wide Vixen-style dovetail plate with cone-angle adjustments
• iEXOS-100-2 PMC-Eight GoTo equatorial tracker with WiFi and Bluetooth
• Eight-core PMC-Eight motion control, tasks distributed across CPUs for smoother tracking
• Heavy-duty 2.5-inch HEX focuser rated to carry 10 lb of imaging equipment

Optical and Mechanical Design

A true air-spaced triplet with an FCD-100 element delivers diffraction-limited performance with residual colour low enough that bright stars record without a violet halo across the field. Carbon fibre matters for two reasons: it cuts weight, which is what lets a 4-inch triplet sit on a compact mount, and it expands far less than aluminium as the night cools, so focus holds through a long imaging session. The mount head weighs 9.45 lb on a 5.35 lb tripod with 1 kg counterweights, rated at approximately 9 lb of equipment alone and 15 lb photographic once counterweights are counted. Tripod height runs 25.5 inches collapsed to 45 inches extended with the head fitted.

Recommended Uses

• Deep-sky imaging of galaxies, planetary nebulae, and smaller clusters at 714 mm
• High-resolution lunar and planetary observing and imaging
• Double star work, where the extra aperture separates closer pairs
• Travel and dark-site trips needing 4-inch apochromatic performance in a light package

Compatibility and Accessory Notes

The 45 mm dovetail plate is Vixen-style and seats in the mount's saddle as supplied; the cone-angle adjustments let you square the tube to the mount for accurate GoTo pointing. At f/7 the telescope falls inside the range of the Explore Scientific field flattener for f/5 to f/7 refractors, which we stock separately, and a 0.7x reducer-corrector is also available for it. The mount runs over WiFi, Bluetooth, or wired serial with the ExploreStars app or any ASCOM-compatible software; a tablet or computer is not included.

Good to Know Before You Order

The 9.5 lb tube sits close to the mount's 9 lb equipment-only rating, so this pairing is best used with the counterweights fitted as supplied and a modest camera rather than a heavy imaging train — talk to us if you plan to add a filter wheel and off-axis guider. Explore Scientific publishes no packing list for this configuration, so the items above reflect the tube and mount specifications they do publish. Eyepieces, diagonal, camera adapters, and a tablet are separate. Published weights are 9.5 lb tube, 9.45 lb mount head, 5.35 lb tripod, 1 kg per counterweight; the checkout shipping weight is the sum rounded up to the next whole pound.

Frequently Asked Questions

Is it difficult to set up? Mechanically no — the dovetail drops in and the counterweights slide on. Polar alignment and star alignment take a first evening to learn, and Explore Scientific publishes guides for both.

Is the mount big enough for this telescope? It is within rating with the supplied counterweights, and fine for a camera or eyepiece. If you intend to hang a full imaging train off the back, a heavier mount such as the EXOS-2GT is the safer pairing, and we can quote that combination.

Why carbon fibre? Lower weight and far less focus drift as the temperature falls, which matters over a long exposure sequence.

Do I need a flattener? For imaging with a larger sensor, yes — the f/5 to f/7 flattener suits this telescope and we stock it.

Bottom Line

A 4-inch FCD-100 apochromat in a carbon fibre tube with a GoTo mount included, giving longer focal length and more aperture without a heavy setup to carry. Our team in Bolton can advise on the flattener and camera train that suit your sensor.