Sky-Watcher Equinox 80ED Review
Sky-Watcher’s Evostar 80 ED DS-Pro is a popular telescope these days. Its combination of modest price, easy mounting and usefully wide field make an ideal starter’s imaging scope. But Sky-Watcher once made another 80ED – the Equinox 80ED – that was a completely different scope, both mechanically and optically.
Here I take a look at the differences between the Evostar 80ED DS-Pro and the Equinox 80ED and compare the Equinox to a premium scope of similar aperture and focal length, the Tele Vue TV-76.
At A Glance
Sky-Watcher Equinox 80ED
Data from Me/SW.
What’s in the Box?
Like others in Sky-Watcher’s premium Equinox range, all you get is an OTA and case, but the case is a higher quality one than the Evostar model, with proper cut camera-case foam instead of ethafoam.
Design and Build
The 80ED was once available in two ranges, the Evostar 80ED DS-Pro and this Equinox.
The Evostar 80ED DS-Pro was the cheaper of the two, with a fixed dew-shield and a rolled tube in their familiar ‘black diamond’ (i.e. white and metallic black) colours with a white cast focuser. It’s the only 80ED doublet Sky-Watcher sell now (they make a much more expensive and heavier triplet too).
The ‘other’ Sky-Watcher doublet 80ED, the Equinox on review here, is different. For one thing, it comes in a shiny black all-CNC tube with a sliding dewshield and CNC focuser. But unlike the larger (100ED and 120ED) Equinox models, the optical spec’ is different too, as we’ll see ...
Update 2021: The Equinox range was once available in 66mm, 80mm, 100m and 120mm (see below) apertures; they’ve all been discontinued. Only the Evostar DS-Pro model is currently available.
Sky-Watcher’s Equinox range once went all the way up to this superb 120ED.
The alternative Evostar 80ED DS-Pro model has the standard SW ‘Black Diamond’ livery with a cast focuser.
The most important thing to understand is that Equinox 80ED is F6.3 (500mm focal length), whilst the cheaper ED Pro is F7.5 (600mm focal length). Why? No idea. Does this matter? Well, on one hand, the ED DS Pro’s longer focal length significantly increases exposure times for deep sky imaging. Whilst on the other, the slower lens has the potential to show less aberrations, both chromatic (false colour and spherochromatism) and monochromatic (like astigmatism, coma and field curvature that distort star images in the outer parts of the field).
Otherwise, the lenses are both ED doublets that are Chinese made, but use glasses from premium Japanese/European brands. Sky-Watcher have strongly marketed their use of Ohara’s FPL-53 for the positive crown element and a high-grade flint from Schott for the negative. FPL-53 is one of the best high-fluoride ED glasses around and is used in many of the best apochromatic lenses.
The lens appears well coated (perhaps better than the typical ‘China green’ used on the ED Pro) and sits in a slim, non-adjustable cell.
The Equinox sports lots of piano-black, too many chrome parts and is a bit too shiny generally. However, the Equinox is beautifully built, whatever you think of the shiny finish. What looks like chrome is chrome, i.e. metal and not plastic (though I’ve heard it can flakes off). The tube looks plastic, but it isn’t - it’s beautifully anodised metal too, which is why the Equinox is heavy. In fact, the external build quality of the Equinox is almost too good, too slick and polished; it looks a bit cheap and flashy, a bit flat-screen TV, especially compared with something like a Tele Vue 76.
The other disadvantage of that CNC tube is that it’s fairly heavy for a scope of this size – about 2.6 Kg. For comparison, the Equinox is a lot heavier than either the Borg 90FL or Takahashi FC-76DC.
Look past the 80ED lens and you find concentric ridge baffles finished in matte black and a generally high level of internal quality as well.
The Equinox focuser is a standard premium Chinese Crayford with a dual speed knob on the right. Mostly it’s made of anodised CNC-machined metal like the tube and is very precise and smooth in operation. I can detect no play in the drawtube, even at full stretch, which is great news for imagers. Not only is it smooth, but the focuser has lots of travel, with a scale for imaging. The focuser remains smooth even with heavy eyepieces.
The Equinox throws in a final feature anyone using refractors on equatorial mounts will appreciate: a rotator for the focuser. The knurled chrome ring in front of the focuser twists to free the whole focuser for rotation. It’s intended as a camera rotator – allowing perfect framing for imaging - but I love rotators for visual use too: you can adjust eyepiece position without risking dumping an expensive diagonal and eyepiece on the floor. The Equinox rotator is a bit stiff, but is still a useful feature.
The larger Equinox models come with tube rings, but the 80ED (and the 66ED too) have a small Vixen (EQ5) compatible dovetail plate attached directly to the tube. This is a less flexible solution than rings, but at least there is a standard ¼-20 thread on the bottom for a camera tripod.
The Equinox 80ED is a bit heavier than the Evostar 80ED DS-Pro, but it still mounts on just about anything, photo tripod and head included (as shown here). You could certainly start off with an EQ5 for imaging, especially since the short focal length will be less fussy about tracking errors.
Sky-Watcher’s Equinox 80ED (right) on a photo tripod, next to Tele Vue’s TV-76.
The Equinox lacks the diagonal, eyepiece and finder you get with the ED Pro, but the case is finer quality and lined with proper foam not packaging style ethafoam, like the Evostar 80ED DS-Pro’s.
In Use – Daytime
Daytime views are sharp, but high-contrast subjects do show some false colour, as you can see from the photo of one of my local Jackdaws below. False colour is a little worse than a Tele Vue TV-76.
This is slightly curious, because the 120ED – supposedly made with the same glasses – has much lower levels of false colour, despite being a much larger aperture and only 1.5 Fs slower at F7.5 vs F6 for this 80ED.
As this image shows, daytime views and photos through the Equinox 80ED are sharp but reveal some false colour.
Deep sky images show some field curvature at the edges, but good coverage. Brighter O-A stars reveal some bloat.
Cropped image of the Moon in twilight through Equinox 80ED shows good detail.
In Use – Astrophotography
The 80ED produces wide, sharp deep sky images. Bloating on bright O-A (blue-white) stars is typically a bit worse than the image above suggests, in which none of the stars are really bright. Field curvature on APS-C isn’t too bad, but a keen imager will want to get a good flattener or reducer.
Images of the Moon are small due to the short focal length (and thus image scale), but sharp and detailed nonetheless (see above).
In Use – Observing the Night Sky
General Observing Notes
The Equinox is a refined scope to use. The focuser is smooth, largely free of image shift and accurate with its fine-focus knob. The long retractable dewshield protects the objective well. The view is generally good, though perhaps not quite as good as the (much more expensive) Tele Vue TV-76 I was testing alongside.
Cool down for a small doublet like this is fast, ideal for quick looks between showers.
The star test looked pretty good, with nice diffraction rings either side of focus.
The Moon showed good detail and took higher powers quite well, but I noticed more stray light bleeding into the black space around the Lunar limb than I did with the TV-76 and I thought contrast was slightly poorer too.
Turning to Mars just after opposition, with a disk size of about 14 arcsecs, views were much the same through the 80ED and TV-76, though the altaz mounts we were using were awkward at the high powers needed to resolve detail. Nonetheless, Syrtis Major was clearly seen in both scopes at 120x, a magnification which still yielded a sharp image with the Equinox 80. I couldn’t see much difference between the two scopes on Mars, but thought high-power focus was a little snappier in the Tele Vue.
If the Moon through the Equinox seemed a bit soft compared to the near-perfect view through the TV-76, the same couldn’t have been said of the deep sky objects we viewed earlier, before Moonrise. Both scopes gave a commendably flat sharp field, with excellent definition on the Orion Nebula and pinpoint stars in the Trapezium. Contrast on the nebulosity was much the same in both scopes, but I thought stars were a bit tighter and more diamond-like in the TV-76, though the difference was tiny.
My observing buddy noted that the view through the ED80 seemed wider and I agreed. When we checked, the FOV was much the same, as expected, but the fainter stars in the ED80 were brighter due to its larger aperture (80mm vs 76mm = 10% more light gathering).
The Andromeda Galaxy, M31, was similar in both scopes and looks great at this focal length which gets much of the galaxy in the field in a way bigger scopes just can’t. Short focal length refractors like this excel on star fields and open clusters, like those running up through Auriga (see image of M36 above).
If you want a lowish cost wide-field astrograph, then the Equinox 80 is an excellent choice if you can find one, thanks to its fast lens and accurate dual-speed focuser. It might make a better imaging scope than the Evostar 80ED DS-Pro version.
You would need a flattener or reducer for serious or full-frame imaging, but this focal length leaves you spoiled for choice when it comes to reducers, with options from Tele Vue through William Optics and Borg too.
The Sky-Watcher Equinox ED is not bad as a grab-n-go or travel scope either, though a bit larger and heavier than the TV-76 that I was testing alongside. It will mount on most small mounts for visual use, including photo tripods.
Performance for both visual and imaging aren’t quite up to the premium standards of Tele Vue, Takahashi and Borg - with slightly less glitteringly pinpoint stars and more scattered light on bright objects like the Moon - but then neither is the price.
The Sky-Watcher Equinox 80ED is recommended as a grab-n-go visual scope or budget astrograph.
Updated by Roger Vine 2021
Sky-Watcher’s Equinox 80ED alongside Tele Vue’s TV-76.
Buy Sky-Watcher Evostar 80ED DS-Pro from Wex here: