Explore Scientific ED102-FCD100 Series Air-Spaced Triplet Telescope in Carbon Fiber + iEXOS-100-02 PMC-Eight Equatorial Tracker (Bundle)

HOYA FCD100 Optics: The 102mm Air-Spaced Triplet Design

At the core of the ED102-FCD100 is an apochromatic, air-spaced triplet objective lens that uses HOYA FCD100 ED glass. The result is razor-sharp, high-contrast images with virtually no chromatic aberration, the false color fringing seen in less-corrected designs.

For you, this means stars are rendered as tight points of light with virtually no purple halos, and planetary and lunar detail is shown with high contrast. The 102mm aperture gathers ample light for faint deep-sky objects while remaining compact and manageable.

714mm Focal Length at f/7: Framing Nebulae and Galaxies

The telescope's native 714mm focal length and f/7 focal ratio give a moderate image scale. It frames medium-sized targets such as the Orion Nebula (M42) or the Hercules Cluster (M13) on a typical camera sensor, while very large objects need a mosaic or the optional 0.8x reducer.

Explore Scientific designed the ED102-FCD100 Carbon Fiber for both astrophotography and grab-and-go visual sessions. To work out your own sampling, image scale in arcseconds per pixel is 206.3 times your camera's pixel size in microns divided by the focal length in millimeters.

Imaging Train Planning: Reducers and Back Focus for the ED102

This bundle does not include a field flattener or focal reducer. For a wider field of view and faster imaging, the optional ES-FR0.8x 0.8x Focal Reducer is made for this carbon fiber tube (FCD100-10207-CF-01). This accessory transforms the telescope into a 571mm f/5.6 system, allowing you to capture more sky in a single frame and gather light more quickly.

The reducer has two elements and needs 55 mm (+/-2 mm) of spacing between the device and the camera sensor, with a 42 mm T-ring for the camera. To connect a DSLR or dedicated astronomy camera you will need the T-ring for your camera and any spacers that bring you to that distance.

The 2.5-inch HEX Focuser: Precision Control for Heavy Cameras

The ED102-FCD100 Carbon Fiber is equipped with a 2.5" HEX focuser, which is robust and capable of supporting heavy imaging gear.

There is no load figure for this carbon fiber tube's focuser in the material we have, so check the weight of your camera train before loading it heavily.

iEXOS-100-02 Mount: The 8-CPU PMC-Eight GoTo System

The iEXOS-100-02 is a computerized German equatorial GOTO tracking system designed for portable astronomy and astrophotography. It uses Explore Scientific's PMC-Eight Precision Motion Control system, which uses eight independent CPUs to manage mount functions. This improves responsiveness, reliability, timing precision and tracking accuracy compared to traditional single-processor mounts.

Key features of the iEXOS-100-02 mount include:

• Wireless Control: Built-in WiFi and Bluetooth let you control the mount without cables using the free ExploreStars app for Windows, Android, Amazon Fire and Apple tablets.
• ASCOM Compatibility: The PMC-Eight ASCOM driver and POTH Client allow wired or wireless control from most ASCOM-supported astronomy software.
• Weight Capacity: Explore Scientific's site gives up to 19 lbs total, including the telescope, accessories and counterweights; its 2026 catalog rates the mount at 19 lbs for visual use and 15 lbs for photography.
• Belt-Driven Motors: Quiet dual-axis precision stepper motor belt drives.
• User-Friendly Design: Features like a built-in polar alignment sight hole, bubble level, and glow-in-the-dark markings simplify setup in the dark. The included battery pack mounts to the tripod leg bracket and uses 8 C-cell batteries (not included). Alkaline batteries typically last less than two hours, so use a compatible lithium-ion power bank or AC power adapter for extended use.

Visual Observing with the ED102: From 1.14" Resolution to Wide-Field Views

With a theoretical resolving power of 1.14 arc-seconds, the ED102-FCD100 delivers stunning views for the visual astronomer. Under good seeing this helps with close double stars and with cloud bands on Jupiter and the rings of Saturn.

For deep-sky observing, the telescope's 714mm focal length pairs well with low-power, wide-field 2-inch eyepieces. You can sweep through the rich star fields of the Milky Way, frame entire open clusters like the Pleiades (M45). A star diagonal and eyepieces are required for visual use and are not part of this bundle's box list.

Carbon Fiber Build

The optical tube assembly is made of carbon fiber. The carbon fiber construction significantly reduces weight without sacrificing rigidity, making the telescope easier to handle and improving performance on any mount.

The telescope attaches to the iEXOS-100-02 by a dovetail bar that slides into the mount's mounting platform, as the mount's manual describes. Explore Scientific's material for this carbon fiber tube does not detail its rings or finder base.

First Night Out: A Step-by-Step Guide to Your First Session

Getting started with the ED102 and iEXOS-100 bundle is a straightforward process.

1. Assembly and Balance: Begin by setting up the tripod and attaching the iEXOS-100 mount head. Slide the ED102's dovetail bar into the mounting platform. Attach the two included 1 kg counterweights and carefully balance the telescope in both Right Ascension and Declination axes. Proper balance is key to accurate tracking.
2. Power and Connectivity: Install 8 C-cell batteries in the included power pack and connect it to the mount's 12V DC in port. On your Windows PC or tablet, connect to the mount's WiFi network (SSID: PMC-Eight-xxxx, password "PMC-Eight" per the manual).
3. Polar Alignment: Perform a rough polar alignment by sighting Polaris (in the Northern Hemisphere) through the mount's polar alignment sight hole through the RA axis.
4. GoTo Alignment: Launch the ExploreStars app. The app will guide you through a 2-star or 3-star alignment process. Simply command the mount to slew to a bright star, center it in your eyepiece or camera, and sync. Repeat for a second (or third) star.
5. Explore the Sky: With alignment complete, you are ready to explore. Use the ExploreStars app to select a target from its database of thousands of astronomical targets and command the mount to "Slew to Object." The telescope will automatically move to your target and begin tracking it across the sky.