The Sky-Watcher S11100 Pro 80ED APO Telescope offers up to 171x magnification and is suitable for lunar, planetary, binary/star cluster, and galaxy/nebula observation. Apochromatic ED doublet refractor optics that feature a crown glass front element of Schott Glass, a 3.1" (80mm) aperture, 600mm focal length and f/7.5 focal ratio offer high-quality observation. Polished from high grade FPL-53 ED (Extra-low Dispersion) glass, the ED element minimizes chromatic aberration to produce images with enhanced sharpness, and reduce false color halos and fringing.
Equipped with a fully-multicoated 8 x 50mm right-angle finderscope, the Pro 80ED telescope offers enhanced brightness and contrast. With the MHC (Metallic High-Transmission Coating) antireflection multicoating, the air-to-glass surface in the Sky-Watcher Pro 80ED helps minimize light scatter, and offers enhanced contrast and high light transmission. The contrast-enhancing internal light baffles in the tube, the focuser drawtube, and a specially darkened tube interior help provide dark sky backgrounds and high terrestrial contrast. The dew shield helps slow down the formation of dew on the lens in cold weather and improves contrast.
The 2" (5.08 cm) Crayford focuser features dual speed focusing and has 2 coarse focusing knobs. The right knob integrates a smaller concentric knob with 10:1 reduction gear microfine focusing for precise image control during high magnification viewing, and DSLR or CCD imaging. With ribbed gripping surfaces, the large focus knobs are easy to operate, even while wearing gloves or mittens in cold weather. You can adjust the tension on the drawtube to accommodate varying eyepiece/photo accessory loads, as well as firmly lock in a photographic focus.
The Pro 80ED features a 2" (5.08 cm) mirror star diagonal that has 99% reflectivity dielectric mirror coatings for high light transmission and easily fits into the focuser drawtube’s 2" (5.08 cm) eyepiece/accessory holder. You can use 1.25" (3.17 cm) eyepieces by placing the supplied 1.25" (3.17 cm) accessory adaptor into the 2" (5.08 cm) diagonal. By inserting the adaptor into the 2" (5.08 cm) accessory holder on the focuser drawtube, you can use a 1.25" (3.17 cm) image erecting diagonal, or 1.25" (3.17 cm) photographic accessories.
The telescope integrates dual hinged split-ring tube rings, and a dovetail mounting bar that fits into the Vixen-style dovetail slot on the head of several Altazimuth and German equatorial mounts. The Pro 80ED APO Telescope comes in a foam-fitted aluminum-clad shipping/storage case.