Product Description

The Skywatcher ED-APO refractors provide the finest images obtainable-bar none-in their design class. If you are on a quest for the ultimate in pristine, near textbook-perfect astronomical imaging, look no further. Skywatcher ED-APO refractors deliver dramatic coal-back skies and faithful, contrast-rich views of planetary and deep-space phenomenon that are second to none. Skywatcher ED-APO refractors are the logical choice as an investment in advanced instrumentation for exceptional viewing or photography. The Skywatcher ED-APO design assures virtual elimination of secondary, residual "false color" normally present in 2-element achromatic lens designs using Crown and Flint glass. Skywatcher APO refractors utilize a second lens element made from the mineral fluorite instead of Flint glass. Fluorite, CaF2, is a halide with unique properties and a hardness of only four. It is an exotic and difficult material to fabricate into a lens. Hence the cost of manufacturing a fluorite lens is quite high compared to a Flint lens element, for instance. Fluorite's molecular properties have several distinct advantages. First, it has superior dispersion characteristics compared to pure silica-based glass. It functions as a high-index lens with very low dispersion. The term ED to signifies "Extra-low Dispersion". Fluorite also corrects well for spherical aberration. Skywatcher utilizes only the very finest available fluorite lens, FPL-53.

Product Details

• Brand: Sky-Watcher
• Model: S11620
• Dimensions: 95.90 pounds

Features

• Telescope Tube Attachment Hardware: The optical tube comes with attachment hardware that allows it to be securely fastened to the SW EQ5 PRO mount. These quick-release tube rings are cast-aluminum, power coated white
• The Sky-Watcher EQ5 PRO equatorial mount is a premium-grade observing platform utilizing quality mechanical and electronic component materials throughout
• Equatorial Body: The elegantly appointed equatorial body is cast from virgin aluminum and powder coated in classic scientific instrument white
• Motors, Gears & Bearings: Sky-Watcher EQ5 PRO computer models utilize high-torque DC stepper motors with 1.8? angle steps yielding resolution of 0.28764 arc-seconds
• Mechanical Surface Controls: Thumb-locks are provided in RA and Dec. to allow swift manual orientation of the optical tube assembly. Micrometric elevation and azimuth controls are provided to help achieve precise polar alignment