Explore Scientific ED80 80mm f/6 Triplet Refractor Telescope

On a clear weeknight, the telescope that gets used is the one you can carry out in one trip. The Explore Scientific ED80 Essential Series is Explore Scientific's 80 mm f/6 air-spaced triplet with genuine HOYA FCD1 ED glass: a compact apochromat with a two-speed 2-inch rack-and-pinion focuser and a Vixen-style dovetail attached directly to the tube.

Key Features

• Which ED80 this is. Explore Scientific makes two ED80 triplets with the same 480 mm focal length, f/6 ratio and 18.5-inch tube. This Essential Series (ES-ED0806-02) uses HOYA FCD1 glass and the 2-inch rack-and-pinion focuser. The ED80-FCD100 Series uses HOYA FCD100 glass and a 2.5-inch hex focuser rated for imaging setups up to 10 lb. The Essential costs less.
• Optics. A compact, true apochromat built to minimize chromatic aberration, with its FCD1 element protected between two other air-spaced elements and coated with proprietary EMD multi-layer coatings.
• Focus and back focus. The focuser comes with extension tubes, which thread on between the focuser and the diagonal when you need more back focus. In Astronomy magazine's review, Glenn Chaple reached focus with most eyepieces once he fitted one.
• At the eyepiece. In the same April 2017 review, at 150x he resolved the Double Double with each star a pinpoint, and he held a steady view of a magnitude 12.1 star.
• Imaging. Explore Scientific's 0.8x Focal Reducer fits ES-ED0806-02 and turns the 480 mm f/6 into 384 mm at f/4.8; its Field Flattener f/5 to f/7 keeps the focal length and is for photography only. Both need 55 mm (±2 mm) of spacing to the sensor and take a T-ring.

Who It's For

• Grab-and-go visual observers. Explore Scientific built its Twilight I mount for refractors such as the AR102, the ED102 and this ED80, up to 18 lb.
• First imaging setups. This tube is a match for the iEXOS-100-2 tracker, rated for about 9 lb of equipment.
• Imagers who need a guide scope. It is small enough to mount as a guide scope and still suits deep-sky imaging.
• Choosing an ED80. For a heavy camera train, the FCD100's hex focuser is rated for 10 lb. For more aperture, the ED102 Essential Series collects (102 ÷ 80)², about 1.6 times, the light at 9.62 lb.

Accessories & Compatibility

• Finder. Not included. The Hybrid Finder Scope Base accepts all legacy Explore Scientific finder brackets and mini dovetail-type finder brackets.
• Eyepieces. The 99% reflective 2-inch diagonal takes 2-inch eyepieces, and its 1.25-inch adapter takes the rest.