Explore Scientific FCD100 ED80 Triplet APO with 2" Field Flattener & iEXOS-100 GoTo Mount

Premium Glass, Flat-Field Imaging, Portable Performance

For imagers who want edge-to-edge sharpness without altering focal length, this package combines Explore Scientific’s FCD100 ED80 Air-Spaced Triplet APO Refractor with the 2" Field Flattener and the compact yet capable iEXOS-100-2 PMC-Eight GoTo Equatorial Tracker Mount—including two extra counterweights for proper balance. Together, they form a complete, portable astrophotography and observing system that excels at both deep-sky imaging and visual astronomy.

The Telescope: FCD100 ED80 Triplet APO

The FCD100 edition of the ED80 elevates an already excellent design with premium HOYA FCD100 ED glass, known for its superior color correction, contrast, and light transmission. This glass improves sensitivity to red wavelengths—ideal for capturing emission nebulae—and provides tighter star profiles with virtually no false color.

• 80mm aperture, 480mm focal length (f/6)

• FCD100 ED triplet optics virtually eliminate chromatic aberration

• EMD enhanced multi-layer coatings maximize light throughput and contrast

• 2.5" hexagonal rack-and-pinion focuser supports up to 10 lbs of imaging gear

• Compact 91mm OTA diameter for portability and piggyback use

Visually, it’s an outstanding grab-and-go refractor. For imaging, it delivers the clarity and contrast that serious astrophotographers demand.

The Accessory: 2" Field Flattener

The included 2" Field Flattener is designed for refractors in the f/5 to f/7 range, making it an ideal partner for the ED80. Instead of changing the focal length, it corrects the natural curvature of the field, ensuring stars remain sharp to the very edge of the frame.

• Maintains native focal length (480mm, f/6)

• 38mm clear aperture illuminates large imaging sensors

• 55mm backfocus (+/- 2mm) simplifies DSLR and astro-camera connection

• Standard T-thread interface (just add your camera T-ring)

• Fully multi-coated optics for maximum contrast and transmission

• Premium anodized finish for durability

For imagers, this means pinpoint stars across the entire frame—critical for modern wide-field astrophotography.

The Mount: iEXOS-100-2 PMC-Eight GoTo Tracker

The iEXOS-100-2 is a portable yet powerful German equatorial GoTo mount equipped with Explore Scientific’s advanced PMC-Eight Precision Motion Control system. It’s designed to deliver accurate tracking and versatile wireless control in a lightweight form factor.

• 19 lb payload capacity (scope + accessories + counterweights)

• Wireless control via ExploreStars app (iOS, Android, Windows)

• ASCOM compatibility for astrophotography integration

• German equatorial design ensures precise tracking with no field rotation

• Eight-core processor system provides smooth, responsive performance

• Glow-in-the-dark markers, bubble level, and polar alignment tunnel ease setup

• Mount head weighs only 9.45 lbs, tripod just 5.5 lbs—easy to transport

• Includes four counterweights total (two standard + two extras in this package)

For backyard observers and traveling imagers alike, the iEXOS-100 provides an excellent balance of capability and portability.

Cloudy Nights Insights

On Cloudy Nights, users of the FCD100 ED80 with a field flattener consistently report:

• Tighter star fields across large sensors, with no edge distortion.

• A noticeable improvement in contrast and color balance compared to FCD1 versions.

• That the combination is one of the most cost-effective ways to achieve premium APO imaging performance in a small, travel-friendly package.

• The iEXOS-100 mount is widely appreciated for its portability and wireless GoTo system, though owners emphasize the importance of careful balance and polar alignment for best results.

What’s Included

• Explore Scientific FCD100 80mm Air-Spaced Triplet APO Refractor OTA

• Explore Scientific 2" Field Flattener

• iEXOS-100-2 PMC-Eight Equatorial Tracker Mount with WiFi & Bluetooth

• Travel tripod with accessory tray

• 99% reflective 2" diagonal

• 2.5" hex focuser with two extension tubes

• Hybrid Finder Scope Base (finder not included)

• Built-in dew shield & dust cover

• Four counterweights total (two standard + two extras)

Observing Tip

With the field flattener installed, the FCD100 ED80 is superb for framing large nebulae, clusters, and galaxies while maintaining sharp stars across the frame. For visual observing, swap the flattener for the diagonal and enjoy razor-sharp lunar and planetary views with APO clarity. Many imagers keep this setup as their travel rig of choice, thanks to its portability and premium glass.

Final Thoughts

The Explore Scientific FCD100 ED80 APO with 2" Field Flattener and iEXOS-100 Mount is a complete astrophotography package for those who want premium glass, flat-field imaging, and precision tracking in a compact, affordable setup. Whether you’re upgrading from an entry-level refractor or looking for a portable wide-field APO that won’t compromise on quality, this package checks every box.