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The Sky-Watcher Equinox Series SW ED-APO astrograph's 80mm aperture with 500mm focal length delivers stunning images photographically or visually with optional accessories and it has beautiful to behold gleaming black and chrome machined surfaces. The SW 80ED includes sophisticated MHC optical coatings, slide-out lens shade, precision 2-speed Crayford-style focuser and foam-lined aluminum carry case. The attachment bracket mounts to any platform utilizing a 1/4-20 threaded attachment screw.
A dovetail plate is attached facilitating the attachment of an optional viewfinder. The back cell can be independently orientated relative to the position in which the optical tube is mounted. In a given aperture size, refractors will always exhibit sharper images than other optical designs because the refractor concentrates more light into the central airy-disk and first diffraction rings. There is no diffraction pattern interference caused by a diagonal mirror, or secondary mirror being suspended in the optical path (central obstruction) as is the case with reflectors.
Sky-Watcher ED-APO refractor provides the finest images obtainable-bar none-in their design class. Sky-Watcher ED apochromatic refractor delivers dramatic coal-back skies and faithful, contrast-rich views of planetary and deep-space phenomenon that are second to none. Sky-Watcher ED-APO refractor is the logical choice as an investment in advanced instrumentation for exceptional viewing or photography.
The Sky-Watcher ED-APO design assures virtual elimination of secondary, residual "false color" normally present in 2-element achromatic lens designs using Crown and Flint glass. Sky-Watcher APO refractor utilizes 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.