Explore Scientific FCD100 ED80 Triplet APO with 2" Field Flattener (OTA Package)

Premium Glass, Flat-Field Imaging in a Compact APO

The Explore Scientific FCD100 ED80 Air-Spaced Triplet Apochromatic Refractor has become one of the most respected small-aperture APOs for astrophotography. In this package, it comes paired with the Explore Scientific 2" Field Flattener, creating a compact astrograph that delivers edge-to-edge sharpness across modern imaging sensors.

This package includes only the OTA (optical tube assembly) and field flattener—ideal for astrophotographers who already own a mount or want to integrate the ED80 into a larger system.

The Telescope: FCD100 ED80 Triplet APO

HOYA’s FCD100 extra-low dispersion glass provides superior chromatic correction, contrast, and transmission, especially in the red portion of the spectrum where emission nebulae shine. Paired with Explore Scientific’s air-spaced triplet design and EMD enhanced multi-layer coatings, the result is brilliant, high-contrast images with virtually no false color.

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

• FCD100 triplet optics for outstanding color correction

• 2.5" hexagonal rack-and-pinion focuser handles heavy cameras and accessories (up to 10 lbs)

• Compact OTA (91mm diameter) for easy transport or piggyback mounting

• Built-in dew shield & dust cap for protection in the field

This is an OTA designed with astrophotographers in mind—small enough to travel, powerful enough to capture deep-sky nebulae and galaxies with clarity.

The Accessory: 2" Field Flattener

The included 2" Field Flattener is designed for refractors with focal ratios between f/5 and f/7, making it a perfect match for the f/6 ED80. It corrects natural field curvature while preserving the scope’s native focal length, delivering pinpoint stars across the frame.

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

• 38mm clear aperture provides strong sensor illumination

• 55mm backfocus (+/- 2mm) for easy DSLR or astro-camera setup

• T-thread connection for simple camera attachment (T-ring required)

• Fully multi-coated optics for maximum transmission

• Premium anodized finish for durability

With this flattener in place, the ED80 becomes a flat-field astrograph, ideal for large nebulae, star clusters, and wide-field galaxy imaging.

Cloudy Nights Insights

On Cloudy Nights, the FCD100 ED80 paired with a field flattener is widely praised for:

• Sharper star fields and improved edge performance on APS-C and full-frame sensors.

• Excellent contrast and color rendering, particularly for emission nebulae.

• A cost-effective way to achieve premium APO performance in a compact, travel-friendly form.

• Its versatility—serving equally well as a dedicated imaging scope or as part of a dual-scope system when piggybacked on a larger instrument.

What’s Included

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

• Explore Scientific 2" Field Flattener (with T-thread interface)

• 99% reflective 2" diagonal

• 2.5" hexagonal focuser with two extension tubes

• Hybrid Finder Scope Base (finder not included)

• Built-in dew shield & dust cover

Observing Tip

Imagers who already own a reliable equatorial mount will find this package the perfect way to expand their capabilities. Pair the FCD100 ED80 + flattener with a DSLR or cooled astro-camera, and you’ll have a flat-field, high-contrast wide-field rig capable of capturing the North America Nebula, the Heart & Soul Nebula, or the Veil Complex in stunning detail.

Final Thoughts

The Explore Scientific FCD100 ED80 APO with 2" Field Flattener (OTA Package) is a complete imaging solution for astrophotographers who already have a mount. With premium glass, sharp flat-field performance, and a compact form factor, it’s an ideal upgrade or addition to any imaging arsenal.