The Sky-Watcher Evostar 100ED Refractor Telescope (MSRP $950), sits in the middle of its Evostar refractor line, which includes the smaller 80ED and the larger 120ED. While not cheap, top-notch telescopes in this range often sell for many times more. Also, the Evostar 100ED comes unusually well-appointed for a telescope advertised as an optical tube assembly only. In addition to the telescope itself, you get 25 mm and 5 mm eyepieces (both of which are a cut above the throwaway eyepieces seen in some other scope packages) a right-angle 8X50 finder and bracket, tube rings, a Vixen-compatible plate, a two-inch dielectric diagonal, and a fitted foam-lined aluminum case. If you were to go out and buy the accessories alone, you might find yourself spending $350 or more on them.
The scope itself comes with a 2-inch dual-speed Crayford-style focuser and has Sky-Watcher’s recognizable black and gold-speckled finish. The tube and drawtube both contain internal baffles, and the entire assembly – outfitted for use – weighs 10.6 lbs, considered light for its class. In short, the telescope is an excellent attempt to check off all the boxes and give people like me very little to talk about. The telescope has excellent pinpoint optics, and the ED glass keeps the chromatic aberration (false color) to virtually undetectable levels. The star test (a visual way to measure distortion in optics) also gave me very little to talk about, as both the intrafocal and extrafocal star images were nearly identical. The 100ED works well on mid-sized mounts like Celestron’s CG-5/AVX and its clones from Meade, Orion, iOptron, and Sky-Watcher itself.
Traditionally, refractors excel at looking at the planets, moon, and double stars, and the Evostar 100ED is no exception. During the review period in late 2020, Saturn and Jupiter were sinking low in the sky. But under good conditions, Saturn’s Cassini division within its rings snapped into focus, as did Titan and a handful of its other moons. Jupiter’s two cloud belts are easy, as are shadow transits with its four bright moons. Mars was just past opposition, and its tiny white polar ice cap popped into view during times of good seeing. Among double stars, the author favors Iota Cassiopeia, a tight triple star system with a large magnitude difference between its components. With the 5 mm eyepiece (180X) under the right conditions, all three components could be seen.
Performance-wise, only its relatively small 4-inch aperture keeps it from being a useful tool for hunting down dim, deep sky objects. Many amateur astronomers choose to supplement a 4-inch refractor with a larger Newtonian reflector or Schmidt-Cassegrain (in both classes, 8-inch is a popular aperture). The brighter deep sky objects, however, are easy to see through the Evostar 100ED. In one productive evening alone, the author saw clusters M45, M37, M36, M38, NGC 457, the Andromeda and M33 galaxies, the Orion Nebula, and more.
If you’re looking for a 4-inch apochromatic refractor and don’t want to spend a small fortune, the Evostar 100ED comes highly recommended. For more in-depth information on the Skywatcher Evostar ED100, check out Ed’s YouTube review: