Evostar 80mm Doublet APO Refractor (S11100) Sky-Watcher USA

Sky-Watcher Evostar 80ED APO Refractor: Portable Optical Powerhouse!
Due to their unobstructed textbook-like diffraction patterns and exotic optical properties, the Evostar ED-APO produces the sharpest, highest quality imaging obtainable from any telescope optical design.  These breathtakingly pristine celestial views are coveted by experienced amateur astronomers.

Observing with SW Evostar ED-APO 80 mm Refractor
Fortunate indeed is the amateur astronomer with a SW Evostar ED-APO 80 mm refractor on a clear night with transparent skies and a stable atmosphere.  The Sky-Watcher Evostar ED-APO 80mm is a modestly wide-field telescope offering bright, wide swaths of sky in a single view.  It is well suited for wide-field astronomical observation of prominent nebulae, star clusters and galaxies from a dark-sky location, or can be used as an astrograph for sky photography.  As a terrestrial spotting scope or telephoto lens, the Evostar ED-APO’s performance is absolutely superb.  Ultra high contrast allows the subtlest of details to be easily scrutinized under conditions of good seeing.  The petite silhouette of the SW ED-APO 80 mm makes for an excellent compact, portable telescope that travels light and fits a small space.  At about 50-power, structural detail becomes apparent in our solar system’s gas giants like Saturn and Jupiter.  The Moon also exhibits striking crater detail along the lunar terminator.

As an astrograph, the SW Evostar 80ED delivers superb performance imaging a wide spectrum of astronomical phenomenon.

Refractors—the Ultimate Imaging Instruments
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 Evostar ED-APOs—the Ultimate Refractors
Sky-Watcher Evostar 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! Sky-Watcher Evostar ED apochromatic refractors deliver dramatic coal-black skies and faithful, contrast-rich views of planetary and deep-space phenomenon that are second to none.  Sky-Watcher Evostar ED-APO refractors are the logical choice as an investment in advanced instrumentation for exceptional viewing or photography.

Virtually Eliminates Residual Chromatic Aberration 
The Sky-Watcher Evostar ED-APO design assures virtual elimination of residual “false color” (i.e. chromatic aberration) normally present in 2-element achromatic lens designs which utilize standard crown and flint glasses.

Sky-Watcher APO refractors utilize the finest extra-low dispersion (ED) glass available, FPL-53.  This results in the best color correction for an ED doublet lens.

Schott Glass Used for Front Crown Element and ED 2 Lens Element
The Evostar 80ED will benefit from the inclusion of Schott glass being used for the positive front Crown element in the objective.  Schott is the recognized world leader in glass utilized for precision optical lens systems, including medical instrumentation and famous-brand camera lenses.  While Schott glass is only used in selected models, all other models utilize top-quality, Grade-A glass from perhaps less famous but, nonetheless, highly respected, high-quality glass manufacturers.

Pride and Perfection in Optical Manufacturing
Every lens element is individually inspected for purity and absence of striae and other image-degrading imperfections.  Every lens is pitched polished to exacting standards of optical fabrication and performance by highly skilled opticians utilizing state-of-the-art methodology and rigidly controlled optical testing procedures.  The result is high-quality, diffraction-limited optics performing to the theoretical limits of their respective aperture sizes.  All lenses are uniformly air-spaced in their cell housings.

Sky-Watcher offers one of the most extensive lines of ED-APOCHROMATIC refractors in the world.  Using only the finest fabrication materials available, Sky-Watcher APO refractors are manufactured to painstakingly rigorous, exacting standards of optical and mechanical quality to insure the amateur astronomer peak performance and a great experience each and every time a Sky-Watcher Evostar ED-APO is taken into the field.  We know the amateur astronomer has very high expectations regarding astronomical equipment purchases.  Sky-Watcher has been delivering consistent satisfaction for over a decade.

Metallic High-Transmission Lens Coatings 
Each air-to-glass lens surface has exotic anti-reflection metallic coatings applied to ensure optimum light through-put.  The proprietary Sky-Watcher “Metallic High-Transmission Coatings” (MHC) are the finest photon anti-rejection coatings in their class.

Light-Baffled Optical Systems
The objective lens cell is light-baffled to reject stray, unfocused light.  The draw tube is likewise baffled to insure optimum contrast.  The tube interior is flat blackened to help prevent unfocused internal light reflections from reaching the focal plane.

Precision 2″ Crayford-style Focuser is Standard
Optical focus is achieved by means of a mechanically ultra-smooth, backlash-free, precision 2″ Crayford-style focuser-assembly with 1.25″ adaptor.  Focuser offers 2 speeds for fine and ultra-fine focusing adjustments.