Sky-Watcher EvoStar 80 APO Doublet Refractor - Compact Portable Optical Tube for Astrophotography (S11100) Review (2026)

A middle ground focal length for first imaging setups

The EvoStar 80, sold under part number S11100, is an 80mm apochromatic doublet refractor with a 600mm focal length and an f/7.5 focal ratio, sitting between the wider field EvoStar 72 and the longer focal length EvoStar 100 in Sky-Watcher's APO lineup. That middle ground focal length makes it a popular choice for observers moving into deep sky astrophotography for the first time, since 600mm is long enough to resolve meaningful detail in medium sized nebulae and galaxies while still being forgiving of small mount tracking errors compared with longer focal length scopes. The doublet objective uses Schott BK-7 glass paired with FPL-53 ED glass, an air spaced two element design intended to minimize false color.

What is included for visual use

Unlike a bare optical tube, this EvoStar 80 kit includes a 2 inch dual speed Crayford style focuser, a 2 inch dielectric diagonal, two 1.25 inch eyepieces at 5mm and 25mm focal lengths, an 8x50mm right angle finderscope, tube rings and a V-style dovetail plate, giving a buyer everything needed for visual observing straight out of the case aside from a mount. The tube itself uses an aluminum housing with a glossy black diamond metal flake finish and ships in a foam lined aluminum case, matching the presentation of the larger EvoStar 100. Metallic High-Transmission Coatings on the optics are intended to virtually eliminate false color across the included eyepiece range.

Moving from visual to imaging

For observers planning to add a camera later, the 600mm focal length at f/7.5 works well with common astronomy camera sensor sizes without needing as aggressive a field flattener correction as faster, shorter focal length scopes sometimes require, though a flattener is still recommended for pinpoint stars across a full frame. The dual speed focuser's fine adjustment ring becomes especially useful once a camera replaces an eyepiece, since achieving critical focus by eye through a viewfinder or live view screen benefits from smaller, more controlled focus movements than a single speed focuser allows.

Mount and accessory considerations

At 80mm aperture, this scope needs a mount with more carrying capacity than the smaller EvoStar 72 but less than the larger EvoStar 100, making a mid size equatorial mount a reasonable match for either visual or light imaging use. Buyers should budget for a field flattener if they plan to image, since one is not included with the optical tube, and a sturdy mount remains the single biggest factor in how satisfying an experience this scope delivers, since even excellent optics will show star trailing or blur on an undersized or poorly polar aligned mount.

Verdict and how it compares

The EvoStar 80 ranks fifth among apochromatic telescopes in this comparison, trailing the larger EvoStar 100 and 72 as well as two SVBONY triplet models, reflecting a more modest aperture relative to its stablemates even as it remains a capable, well rounded choice. Its blend of a complete visual accessory kit, a friendly entry level price and a versatile 600mm focal length make it a sensible first apochromatic refractor for someone stepping up from a basic achromatic scope, while more experienced imagers chasing maximum resolving power will likely outgrow it in favor of a larger aperture or a triplet design.

Frequently asked questions