Sky-Watcher EvoStar 80 ED 80/600 1:11 Apochromatic Refractor OTA - Only tube with accessories, without mounting, without tripod

Sky-Watcher EvoStar 80 ED 80/600 f/7.5 1:11 Apochromatic Refractor OTA

The Sky-Watcher EvoStar 80 ED is one of the most popular and highly regarded apochromatic refractors in the amateur astronomy world - and for good reason. This 80 mm f/7.5 ED doublet combines genuinely excellent optical performance with a compact, lightweight body and a comprehensive accessory package, all at a price that is hard to match among true apochromatic instruments. Whether you are taking your first steps in astrophotography, upgrading from an achromatic refractor, or looking for a versatile grab-and-go telescope that can do it all, the EvoStar 80 ED deserves serious consideration.

ED Doublet Optics - Colour Correction Without Compromise

At the heart of the EvoStar 80 ED is a two-element air-spaced objective lens incorporating one element made from high-grade ED (Extra-low Dispersion) glass. Sky-Watcher specifies the use of Ohara FPL-53 synthetic fluorite glass for the positive crown element, paired with a high-grade Schott flint glass for the negative element. This combination is the same pairing used by several significantly more expensive instruments from premium manufacturers, and it is the foundation of the EvoStar's outstanding chromatic correction.

Chromatic aberration - the tendency of a lens to focus different wavelengths of light at slightly different distances, resulting in coloured halos around bright objects - is the defining weakness of simpler achromatic refractors. In the EvoStar 80 ED, this problem is reduced to levels that are negligible for all practical purposes. False colour is essentially invisible under typical observing conditions and only becomes detectable on the very brightest stars at high magnification - a level of correction that rivals much more expensive triplet apochromats in this aperture class. The slow focal ratio of f/7.5 further assists chromatic correction and makes it easier to achieve high magnification without very short focal-length eyepieces.

All air-to-glass surfaces in the objective carry Sky-Watcher's proprietary MHTC (Metallic High-Transmission Coatings) fully multi-layer antireflection coatings. These coatings minimise light loss and internal reflections, maximising contrast and image brightness. The interior of the tube is finished in matte black with dual baffles positioned to intercept stray and unfocused light before it can reach the focal plane - an important detail that contributes significantly to the deep, rich black sky background that the EvoStar delivers at the eyepiece.

What You Can Observe

The EvoStar 80 ED is a genuinely versatile telescope that performs well across a wide range of astronomical targets. The 80 mm aperture and 600 mm focal length place it firmly in wide-field territory, and the colour-corrected optics make it a delight for visual astronomy and a capable astrophotograph in the right conditions.

Open star clusters are among the finest targets for this telescope. Objects such as the Pleiades (M45), the Beehive Cluster (M44), the Double Cluster in Perseus or M35 in Gemini fill the field of view with pinpoint stars against a jet-black background in a way that few other telescope types can match. The wide, flat field and sharp star images right to the edge of a quality wide-angle eyepiece make star-hopping and cluster hunting particularly satisfying.

Bright emission nebulae such as the Orion Nebula (M42), the Lagoon Nebula (M8) and the Omega Nebula (M17) are excellent targets, especially from a moderately dark sky and when paired with a UHC or narrowband filter. The EvoStar's colour fidelity means that the subtle greenish hue of ionised oxygen and the reddish tones of hydrogen-alpha emission are rendered accurately and naturally. The Moon is spectacular through the EvoStar 80 ED - crisp, high-contrast and completely free of the violet fringing that achromats of similar aperture inevitably produce. Planetary observation is pleasing, though 80 mm of aperture limits the amount of fine detail that can be extracted; the telescope shows the main cloud bands of Jupiter, the rings of Saturn and the phases of Venus beautifully, but larger instruments are preferable when planetary detail is the primary goal.

Dual-Speed Crayford Focuser - Precision Without Backlash

Achieving and maintaining precise focus is critical both for comfortable visual observing and for astrophotography. The EvoStar 80 ED Pro (Black Diamond version) is equipped with a high-quality dual-speed 2″ Crayford-type focuser with a 10:1 reduction gearing ratio. The coarse focuser knob moves the drawtube quickly to the approximate focus position, and then the fine adjustment knob - geared at 10:1 - allows extremely precise final focus to be dialled in without any of the image shift or backlash that plagues rack-and-pinion focusers. This is particularly valuable in astrophotography, where even the smallest focus error translates directly into softer star images across the entire frame. The focuser accepts 2″ accessories and includes a 1.25″ reduction adapter for use with standard eyepieces, diagonals and cameras. The drawtube can be rotated and locked at any angle for comfort, and the tension can be adjusted to suit different payload weights.

Astrophotography - A Natural Astrograph

The EvoStar 80 ED was designed from the outset with astrophotography in mind. The combination of apochromatic colour correction, a 600 mm focal length and a precise dual-speed focuser makes it a capable and popular astrograph, particularly for wide to medium field deep-sky imaging. At 600 mm, the field of view is wide enough to capture large objects such as the Orion Nebula complex, the Andromeda Galaxy (M31) or the California Nebula in their entirety, while offering enough focal length to show meaningful detail in medium-sized galaxies, globular clusters and planetary nebulae.

For serious wide-field imaging, the EvoStar 80 ED can be used with an optional 0.85x field flattener/reducer, which brings the effective focal length down to approximately 510 mm and the focal ratio to f/6.4. This accessory also corrects any residual field curvature for perfectly sharp stars from corner to corner even on large APS-C or full-frame sensors. The M48 output thread on the focuser drawtube allows direct connection of standard M48 filter rings, T-rings and camera adapters without the need for additional step-down rings.

The telescope weighs approximately 2.5 kg without accessories, making it light enough for compact equatorial mounts such as the Sky-Watcher HEQ5, EQ5 or equivalent mounts from other manufacturers. Its modest weight also makes it an excellent choice for piggyback mounting alongside a larger main telescope for wide-field guiding or parallel imaging.

Accessories Included in the Package

The EvoStar 80 ED is supplied as a complete package ready for use from the first night. Included in the custom foam-lined aluminium carrying case are a 2″ dielectric star diagonal with 1.25″ reduction adapter, and a 28 mm Long Eye Relief (LER) eyepiece with a 70° apparent field of view, providing a magnification of 21x and a true field of approximately 3.1° - ideal for wide-field sweeping and orientation. The long 20 mm eye relief of this eyepiece makes it comfortable even for spectacle wearers. The tube is equipped with mounting rings and a Vixen-compatible dovetail rail that fits standard EQ and HEQ mounts directly.

Construction and Build Quality

The EvoStar 80 ED Pro (Black Diamond version) features a distinctive glossy black metal-flake tube finish that gives it a premium appearance in the field. The tube is machined from aluminium throughout - there are no plastic structural components - and the overall fit and finish are consistently praised by users as being well above what the price might suggest. The objective cell is fully adjustable for collimation, though the ED doublet design is considerably less sensitive to collimation errors than a reflector and rarely requires adjustment in practice. A retractable dew shield is built into the front of the tube, providing useful protection against dew formation on the objective during long observing sessions and helping to shield the lens from stray light.

Technical Specifications