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Sky-Watcher Evostar 80ED DS-PRO APO
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80mm (3.1”) f/600 Fluorite ED Apochromatic Refractor Telescope
To order this item outside mainland Britain or Highlands & Islands, please contact us.
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- Lens diameter: 80mm
- Focal ratio: f/7.5
- Focal Length: 600mm
- Highest Practical Power (potential): x240
- Multi-Coated Objective Lens
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- Dual-Speed 11:1 2" Crayford Focuser
- 2" (50.8mm) Di-Electric Star Diagonal.
- 2" Eyepiece 28mm LET.
- 9x50 Finderscope.
- Aluminium Carry/Storage case
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Sky-Watcher Evostar 80ED DS-PRO APO O.T.A.
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Outline
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The new EVOSTAR DS-PRO Series ED Apochromatic refractors in their
stunning Black-Diamond livery, house premium optics of the same
quality and performance level as our legendary Equinox series,
making them superb instruments for both imaging and visual observations.
Apochromatic Refractors, due to their unobstructed, text-book like
diffraction patterns, produce the sharpest, highest quality optical
imaging available, bar-none, aperture for aperture, of any telescope
optical system.
These high-end telescopes all feature a doublet objective lens. One
element is made from premium Japanese Ohara FPL-53 Extra-Low Dispersion
(ED) glass, which virtually eliminates chromatic aberration to deliver
true colour reproduction. Top quality Schott glass is utilized for the
Crown element.
Each air-to-glass lens surface has exotic anti-reflection metallic
coatings applied, to ensure optimum light through-put of approaching
99.5%!!
The proprietary Sky-Watcher “Metallic High-Transmission Coatings” (MHC)
are the finest photon anti-rejection coatings in their class.
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ED Apochromatic Refractors
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Premium quality, high performance telescopes for planetary and deep-sky
observaions as well as astrophotography and CCD imaging. The two-element
objevtive lens is fully multi-coated and utilises special, extra-low dispersion
FPL-53 (FPL-51 for the Equinox 66ED APO) fluorite glass for the virtual elimination
of false colour. Performance of these telescopes will both delight and surprise the most critical observer,
and can be genuinely compared to Apochromatic telescopes of other brands in
price brackets normally way beyond the reach of the average user.
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ED Apochromatic Optics: ED Fluorite glass elements minimise chromatic
aberration, provide higher resolution and superior contrast. Colour fringing
around objects is virtually eliminated with this type of optics.
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HEQ5 PRO & EQ6 PRO Heavy-Duty Equatorial Mounts: Specially designed
to support larger telescope tubes, these high-precision mounts feature
engraved setting circles and a latitude scale, built-in polarscope &
retractable counterweight shaft. The worm gears are preloaded with ball
bearings for smooth tracking and slewing. Auto-guiding interface is also
included for long-exposure astrophotography.
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SkyScan PRO Computer-Control GOTO System: The hand controller allows
pointing the telescope to a specific in the night sky at the touch of a button.
The object database contains over 13,400 objects, including complete M, NGC,
and IC catalogues. The positioning accuracy is up to 1 arc minute with
software collimation error compensation. Period error correction (PEC) is
included for astro-photography without auto-guiding.
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Stepper-Motor Technology: The built-in extra quiet stepper motors
produce 800x high slewing speed and a resolution of 0.144 arc second.
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Crayford Focuser: The 2" Crayford focuser is backlash-free. The
focuser wheels contain brushed-aluminium hubs with ridged rubber grip rings.
For more information on the Sky-Watcher PRO mounts please visit the
Sky-Watcher mounts section.
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What Is ED?
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Extra-low Dispersion (ED) glass allows the optical designer to virtually eliminate
chromatic aberration (false colour fringing around bright objects), which results
in higher resolution and superior contrast in the images.
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The amount of secondary spectrum produced by a regular achromatic refractor on left compared with
the Sky-Watcher PRO series ED refractors, which suppress the amount of secondary spectrum to
minimum shown on the right.
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Sky-Watcher Fluorite ED Apochromatic Refractors
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Sky-Watcher PRO series ED refractors are built with a two element air spaced
objective. The second element is made of the highest grade ED fluorite glass
called FPL-53 (FPL-51 for the Equinox 66ED APO). This premium glass choice is
a basic warranty for virtually no false colour and for high contrast. The high
standard set in material choice is also set in production. No efforts are spared
to reach optimal optical quality.
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Test results.
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The company's best opticians give each objective a hand pitch polishing finishing
touch. This dedication to perfection together with aspheric shaping technology
are the best ways to reach a very good wavefront which means virtually no aberrations
and textbook star images. The quality of each ED PRO series objective is
monitored by means of a Ronchi (left image, above) test and a star (right image, above) test.
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The graph on the left shows the performance of an achromatic refractor. The graph on the right
shows the prformance of the Sky-Watcher PRO ED telescopes.
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The essential function of a telescope is gathering starlight without "disturbing" it.
This means changing the path of the lightwaves without altering the lightwave itself.
Lightwaves all together are referred to as a wavefront.
Alterations in this wavefront caused by the optics should be avoided. A wavefront
analysis by Ronchi test will show an absence of wavefront alterations if the black
and white lines (interference pattern) are perfectly straight and parallel.
The star test proves the ability of the optics to reproduce a pinpoint light source
(star) as a pinpoint image. Concentric light circles will surround the pinpoint light dot.
These increasingly faint light circles are unavoidable due to diffraction but being well
concentric around the central light dot they are a warranty for good optical alignment
of the lenses.
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Special Offer
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All products on this page may qualify for the special promotional offer by
Optical Vision Limited (OVL).
This information is correct at the time of writing.
Buy any Sky-Watcher telescope from this web site and buy this Sky-Watcher
Eyepiece & Filter Set at a special price directly from OVL.
Kit Comprises: 2mm, 5mm, 9mm & 15mm Long Eye Relief Eyepieces, and
4 Threaded Light Filters (Amber, Blue, Neutral Grey & Moon
Filter) in lockable, foam-padded Aluminium Case.
This offer applies only in the United Kingdom. For the latest up to date
information please contact OVL.
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Special promotional offer.
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Notice
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We are constantly checking the accuracy of the technical data. We are prepared
to provide more detailed information on request. Technical data is subject to
change without notice.
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