$Sky-Watcher Evostar 100ED APO Refractor — image 1$

Sky-Watcher

Sky-Watcher Evostar 100ED APO Refractor

A 100mm ED doublet at a slow f/9, tuned for crisp, high-contrast visual views of the Moon, planets and double stars at a price that undercuts the triplets.

86/ 100

Polaris Score

#2 of 8 sub-$1000 ED refractor

See the breakdown ↓

Aperture

100mm

Focal Length

900mm

Focal Ratio

f/9

Mount Type

None (OTA only)

Optical Design

ED Doublet Refractor

Weight

4.5 kg

From$1,255

Lowest in 90 days

Price tracked by PolarisObserved 8 timesTracking since Aug 2026

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Where to buy

AstronomicsBest price$1,255→

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What it's built forOpen these in the simulator →

This telescope was built for sweeping wide.

A short, fast refractor with a generous true field — the whole sword of Orion in one view, star fields that spill past the field stop. It rewards low power and dark skies far more than chasing magnification.

Widest true fieldsTack-sharp to the edge

The view people remember

The Pleiades, blue and blazing.

A knot of hot young stars wrapped in the faintest haze of reflected light — best at the lowest power, where the whole cluster drops into a single glittering field.

See The Pleiades through this telescope →

Where else it shines

Within reach

Orion Nebula

Stronger structure — embedded stars plus dark lanes within the core

Open view →

Rewards a dark sky

Hercules Cluster

Brighter core with a hint of granulation around the edges

Open view →

Rewards a dark sky

Andromeda Galaxy

Definite galaxy shape — core stands out against the sky

Open view →

Also excellent on

Saturn

Recognizable disk with subtle markings under steady seeing

Open view →

✦

Tight planetary detail belongs to a longer scope. This one trades reach for a breathtaking field.

01What it's good at

What it's best at — and the trade-offs.

Best at

✓The ED glass suppresses the false-color fringing that plagues cheap refractors, giving clean views on bright targets

✓At f/9 the long focal ratio makes color correction easier and eyepieces perform their best with little edge softening

✓100mm splits tight doubles and shows real detail on the Moon and planets with the contrast refractors are loved for

✓As an OTA it pairs with a modest alt-az or equatorial mount, keeping the whole rig light and quick to deploy

Trade-offs

!f/9 is slow for deep-sky imaging and yields a long tube for the aperture

!As a doublet it shows a trace of residual color on the very brightest objects versus a triplet

!It is an OTA only and needs a mount and diagonal to become a working scope

!The 900mm focal length gives a narrower field than short imaging refractors

02In plain English

What These Numbers Mean

Aperture

100 mm

Four inches of ED glass, enough for detailed lunar and planetary work at 200x and for the brighter deep-sky objects to show real definition. Unobstructed optics give it contrast that a same-size reflector cannot match.

Focal length

900 mm

Fairly long, which suits planets, the Moon, double stars and compact deep-sky targets. It reaches 180x with a 5 mm eyepiece; wide nebulae need a reducer or a shorter scope.

Focal ratio

f/9

Slow enough that the doublet's colour correction is essentially complete and ordinary eyepieces perform well. For imaging it means longer exposures, which is why the shorter Evostar models are more popular with imagers.

Optical design

ED doublet apochromat

Two elements with one ED glass, which removes almost all the violet fringing an achromat shows. At f/9 the design has an easy job, so the result is close to triplet performance for doublet money and weight.

Weight

4.5 kg tube

About 10 lb, but a long tube. Mass is easy to handle; the length means the mount and tripod need to be firm to keep vibrations short.

Mount

OTA only

You supply the mount. A solid alt-azimuth is fine visually, while imaging at 900 mm calls for a tracking equatorial with guiding.

02The Polaris Score

How it scores, and why.

86/ 100

Sky-Watcher Evostar 100ED APO Refractor

#2 of 8 sub-$1000 ED refractor

Performance

Ease of use

Portability

Upgrade potential

Polaris weighs optical capability, how easy the scope is to live with, how portable it is, and how far it takes you before you outgrow it — not list price or brand.

03Who it's for