Sky Watcher Sky-Watcher 120ED PRO Refractor OTA Black Diamond

Sky Watcher Sky-Watcher 120ED PRO Refractor OTA Black Diamond Product Description

Sky Watcher 120ED PRO Refractor OTA Black Diamond Product Info

Sky Watcher high performance ED APO refractors offer premium optical performance for the discriminating amateur astronomer. Refractors are coveted for their superb contrast, high definition, and coal black sky background that make stars appear like diamonds imbedded in black velvet. SW APO refractors utilize the most modern optical glasses and fabricating techniques to deliver the ultimate in high fidelity astronomical imaging. Subtle details pop as never seen before in telescopes of lesser optical capability.

Observing with the Sky Watcher PRO 120ED APO Refractor

The additional aperture compared to a 100mm diameter lens provides a dramatic increase in resolution and a heighten sense of seeing lunar and planetary surface phenomenon in seemingly 3D high definition.

As an astrograph, the SW PRO 120ED APO performs superbly delivering crisp, high fidelity imaging of planetary, lunar and aperture appropriate deep space 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 ED APOs the Ultimate Refractors

Sky Watcher 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 ED apochromatic refractors deliver dramatic coal back skies and faithful, contrast rich views of planetary and deep space phenomenon that are second to none. Sky Watcher 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 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 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 4. 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.

Why fluorite Fluorite 39 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. We use the term ED to signify Extra low Dispersion . Fluorite also corrects well for spherical aberration. Sky Watcher utilizes only the very finest available fluorite lens, FPL 53.

Schott Glass Used in Selected Models for Crown Element
Select models of ED APO refractors 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 1 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 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 rack pinion focuser assembly. This focuser offers 2 speed fine and ultra fine focusing adjustments.

Tube Materials

The optical tube material is aluminum, powder coated reflective gloss black with gold fleck accent. The front and back cells are cast aluminum painted white, or black.

Telescope Tube Attachment Hardware

The Sky Watcher APO optical tubes come with attachment hardware that allows them to be securely fastened to the SW EQ5P mount. The quick release tube rings provided with SW ED APO models 80ED 100ED and 120ED are cast aluminum, painted white.

Specifications

Optical Design	ED Refractor
Lens Material	FPL 53
Diameter	120mm
Focal Length	900mm
Scondary Mirror Diameter	n/a
F/ratio	F/7.5
Highest Practical Power	240x
Faintest Steller Magnitude	13.1
Resoving Power	0.96
Finderscope	8X50 Right Angle or 9x50
Focuser diameter	2
Diagonal	2 inch 90 39 Dieletric Diagonal with 1.25 inch adapter
Eyepiece s	2 inch 28mm eyepiece
Mount Type	n/a
Slow motion Control	n/a
Counterweight s	n/a
Piggyback Bracket	YES
Accessory Tray	n/a
Ground Board Diameter	n/a
Ground Board Weight s	n/a
Motor Drive	n/a
Go to	n/a
Tube Weight	5.13kg
Tube Dimension dia. x length	10 cm x 62cm
Tripod Height	n/a
Shipping Weight	14.5kg
Shipping Carton Dimensions	106.5 x 35.5 x 29 cm3

Package Contents

• Sky Watcher 120ED PRO Refractor OTA Black Diamond