Telescope Comparison
Orion AstroView 90mm EQ Refractor vs Sky-Watcher Evostar 100ED
The Orion AstroView 90mm EQ Refractor is a complete setup. The Sky-Watcher Evostar 100ED needs a mount before it's usable.
First light
Orion · 90mm
The sky-learner's equatorial scope
- 90mm refractor on a manual equatorial mount
- Good for: Moon, planets, bright star clusters and nebulae
- Setup includes rough polar alignment before observing — more steps than a simple alt-az
- Mount axes feel counterintuitive at first; users find they become natural after several sessions
- Keeps the door open for adding tracking motors and moving into astrophotography later
Sky-Watcher · 100mm · £449
The custom-rig optical tube
- 100mm refractor — optical tube only, no mount included
- 900mm focal length at f/9
- Requires a compatible mount before you can observe anything
- Best for: observers who already own a suitable mount or are building a specific imaging rig
- Not a complete purchase — budget at least £100–300 extra for a mount before observing
The full picture
The numbers that separate these two scopes — and what they mean at the eyepiece.
Aperture
Sky-Watcher Evostar 100ED gathers 1.2× more light. On bright targets — Moon, Saturn, Jupiter — you won't notice. On fainter targets — dim galaxies, faint globular clusters — the gap is real.
Focal length
Orion AstroView 90mm EQ Refractor's longer focal length reaches higher magnification with the same eyepiece — better reach for planetary detail. Sky-Watcher Evostar 100ED's shorter focal length gives a wider true field — better for large open clusters and extended nebulae.
Focal ratio
Sky-Watcher Evostar 100ED's faster f/9 delivers wider fields with any eyepiece — better for open clusters and large nebulae. Orion AstroView 90mm EQ Refractor's f/10.1 provides more magnification per eyepiece — better for fine planetary detail.
Mount type
Sky-Watcher Evostar 100ED has no mount — add a compatible mount before you can observe. Orion AstroView 90mm EQ Refractor is a complete ready-to-use system.
Weight (OTA)
Similar optical tube weight. Any portability difference between these setups comes from the mount, not the tube itself.
Optical design
Both are refractors — no mirrors to collimate, good contrast, colour-free stars with ED or APO glass. The differences between them are in aperture, focal ratio, and glass quality.
At the eyepiece
Both scopes · same aperture
Both refractors share essentially the same aperture — views through each will be very similar on all standard targets. The hallmarks of good refractor optics are sharp stars and good contrast on planetary targets, with no false colour on ED or apochromatic glass. Saturn's rings are distinct from the disk; Jupiter shows two equatorial bands. The Orion Nebula (M42) is bright and well-defined. Open clusters are a strength — the Double Cluster in Perseus and the Pleiades look good at low power. The differences between these two scopes show up in focal ratio, focal length, and what they're optimised for, not in fundamental light-gathering capability.
The real tradeoff
Both scopes are capable. The question is which one fits the way you actually observe.
The Orion AstroView 90mm EQ Refractor is a complete package — everything arrives in one box and you can observe the same day. The Sky-Watcher Evostar 100ED is a bare optical tube that needs a separate compatible mount before you can point it at anything, adding significant cost and complexity. Unless you already own a suitable mount, the Orion AstroView 90mm EQ Refractor is the practical choice.
The dark side
Every scope has a personality. Here’s where each one gets difficult.
Orion
Orion AstroView 90mm EQ Refractor
Mount axes feel counterintuitive at first
An equatorial mount does not move up/down and left/right as you expect — it follows the rotation of the sky. Users consistently report that it takes several sessions before it begins to feel natural.
Sky-Watcher
Sky-Watcher Evostar 100ED
No mount included
You cannot observe until you buy a separate compatible mount — add at least £100–300 before you have a working telescope.
Nothing to look through on day one
Until a mount arrives, the optical tube is a piece of glass you cannot point at the sky.
Which is right for you?
Two different buyers. Two different right answers.
The sky-learner's equatorial scope
Orion · Orion AstroView 90mm EQ Refractor
You’ll love this if…
- You want to understand how an equatorial mount works — and you're prepared to spend a few sessions on polar alignment before it becomes second nature
- You plan to observe from a fixed spot in the garden, where the mount can stay roughly polar-aligned between sessions
- Astrophotography is on your radar even if you're not starting there — this mount keeps that option open with a motor drive upgrade
This will frustrate you if…
- You find the equatorial mount's axes feel wrong — objects move in unexpected directions and polar alignment adds a step each session that takes several outings to become automatic
The custom-rig optical tube
Sky-Watcher · Sky-Watcher Evostar 100ED
You’ll love this if…
- You already own a compatible equatorial or alt-az mount — this is the optical tube you've specifically chosen to put on it
- You're building an imaging rig piece by piece and know exactly what you need at the end of a focuser
- Choosing an optical tube independently of the mount gives you more flexibility over your overall system
This will frustrate you if…
- You buy it without fully accounting for the mount — add at least £100–300 to the purchase price before you have a working telescope
- You expected a complete package and didn't realise this is a bare optical tube that cannot be used without a separate mount
Our verdict
This comparison has a catch: the Sky-Watcher Evostar 100ED is a bare optical tube. You cannot use it without a separate mount — which adds meaningful cost and complexity. The Orion AstroView 90mm EQ Refractor is a complete, ready-to-observe package.
For most buyers, the Orion AstroView 90mm EQ Refractor is the right choice — you can observe the same night it arrives. The Sky-Watcher Evostar 100ED makes sense if you already own a compatible mount, or are deliberately building a specific imaging setup piece by piece. If I had to choose for a first telescope: the Orion AstroView 90mm EQ Refractor, without hesitation.
Orion AstroView 90mm EQ Refractor
View Orion AstroView 90mm EQ Refractor →Sky-Watcher Evostar 100ED
View Sky-Watcher Evostar 100ED →Deep field: Full specifications
Every data point, for those who want to go further.
Full specifications
Fields highlighted in blue or amber indicate the better value for that spec. Data is manufacturer-stated and may vary.
How much can it see?
| Spec | Orion AstroView 90mm EQ Refractor | Sky-Watcher Evostar 100ED |
|---|---|---|
Apertureⓘ The most important spec — bigger = more light = better views | 90mm | 100mm |
Focal Length Longer = more magnification potential | 910mm | 900mm |
Focal Ratio Lower f-number = wider field of view; higher = more magnification per eyepiece | f/10.1 | f/9 |
Optical Design The type of optics — each design has different strengths | Refractor | Refractor |
Coatings Better coatings = more light transmission through the optics | Fully multi-coated achromatic doublet | Fully multi-coated ED doublet |
How do you point it?
| Spec | Orion AstroView 90mm EQ Refractor | Sky-Watcher Evostar 100ED |
|---|---|---|
Mount Type The mechanical system that holds and moves the telescope | Equatorial | None (OTA only) |
GoTo Computer-controlled pointing — finds any of thousands of objects automatically | ||
Tracking Motor keeps objects centred as the Earth rotates — essential for astrophotography |
The focuser
| Spec | Orion AstroView 90mm EQ Refractor | Sky-Watcher Evostar 100ED |
|---|---|---|
Focuser Size 2" accepts wider eyepieces and gives better low-power views | 1.25" | 2" |
Focuser Type Rack-and-pinion is standard; Crayford and dual-speed are smoother | Rack and pinion | Dual-speed Crayford (with 1.25" adapter) |
Size & weight
| Spec | Orion AstroView 90mm EQ Refractor | Sky-Watcher Evostar 100ED |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 2.7kg | 2.6kg |
Total Weight Full setup including mount — this is what you lug to the car | 7kg | — |
Tube Length | 910mm | 720mm |
Tube Material | Aluminium | Aluminium |
What's in the box?
| Spec | Orion AstroView 90mm EQ Refractor | Sky-Watcher Evostar 100ED |
|---|---|---|
Eyepieces Included eyepieces — more is better, but quality matters more than quantity | 25mm and 10mm Sirius Plössl | — |
Finder Scope Helps you locate areas of the sky before switching to the main eyepiece | EZ Finder II red dot | — |
Diagonalⓘ Tilts the eyepiece 90° for comfortable viewing — useful on refractors |
Blue highlight: Orion AstroView 90mm EQ Refractor advantage · Amber highlight: Sky-Watcher Evostar 100ED advantage · Greyed cells: equal or subjective.