ED80 Essential Series Air-Spaced Triplet Refractor Telescope with Field Flattener

The ED80 Essential Series Air-Spaced Triplet Refractor is a true apochromatic telescope that reveals celestial wonders like the desolate beauty of the lunar terrain, the serene structure of Saturn’s rings or the brightest deep sky treasures of the Messier catalog. 

Offering true diffraction-limited optics with genuine HOYA FCD1 ED glass, the ED80 is the perfect size to encourage spontaneous stargazing sessions, this high-quality telescope is a perfect grab-and-go instrument for exploring the skies.

Featuring an air-spaced triplet optical design that virtually eliminates chromatic aberrations, this telescope generates brilliant high-contrast images by combining genuine HOYA extra-low dispersion (ED) glass and proprietary EMD enhanced multi-layer deposition coatings on all optical surfaces.

Although it is a standout telescope on its own, the 80mm also is compact enough to mount on a larger telescope, which can add versatility to your astrophotography experience by separating the guiding and imaging duties. 

When doing astrophotography with refractor-type telescopes, the faster the focal ratio the more field curvature becomes a problem. Field curvature will appear in the corners of astrophotographs, making the stars smear perpendicular to the axis of the image. This is called coma -- coma is Latin for comet, because the stars look like comets. The more the curvature, the closer to the center the coma appears. The larger the sensor, the worse the coma.

Astrophotographers can easily correct the coma by using a field flattener – an optical device that goes between the telescope and the camera. Field fatteners are not interchangeable, because these devices are designed to work with a small range of focal ratios.

The Explore Scientific field flattener is designed to work with telescopes with focal ratios between f/5 and f/7. Our device requires 55 mm (+/-2 mm) of spacing between the back of the device and the camera sensor.

NOTE: This device is for photographic use only. It is NOT intended for visual use.

“Then I really went nuts. Or so I thought. I switched to a 3.2mm planetary eyepiece that upped the magnification to 150x, which approached the theoretical upper limit for a 3-inch. When I gazed into the eyepiece, the four members of the Double Double showed surprisingly well, leaving me to wonder what this scope might do on a night of optimal seeing conditions. I have no doubt the ED80 can achieve its advertised resolving limit of 1.45”…. Small and portable, it’s an ideal grab-and-go telescope. It’s also extremely versatile, able to capture wide-field views spanning several degrees while also providing the high power punch to tease out lunar and planetary detail and split close double stars…".