Telescope Comparison
Sky-Watcher Evostar 80ED + HEQ5 Pro vs William Optics Zenithstar 61
The Evostar is a complete setup. The Zenithstar needs a mount before it's usable.
First light
Sky-Watcher · 80mm · £690
The automated deep-sky platform
- 80mm refractor on a computerised mount with motorised tracking
- Good for: Moon, planets, bright nebulae, star clusters, and deep-sky objects
- GoTo system finds any object in its database after initial star alignment — no star atlas needed
- Tracking motors keep objects centred as Earth rotates — useful above 100×, essential for photography
- 22.5kg total — requires a fixed garden spot or car transport
William Optics · 61mm · £499
The custom-rig optical tube
- 61mm refractor — optical tube only, no mount included
- 360mm focal length at f/5.9
- 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 80ED + HEQ5 Pro gathers 1.7× 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
Sky-Watcher Evostar 80ED + HEQ5 Pro's longer focal length reaches higher magnification with the same eyepiece — better reach for planetary detail. William Optics Zenithstar 61's shorter focal length gives a wider true field — better for large open clusters and extended nebulae.
Focal ratio
William Optics Zenithstar 61's faster f/5.9 delivers wider fields with any eyepiece — better for open clusters and large nebulae. Sky-Watcher Evostar 80ED + HEQ5 Pro's f/7.5 provides more magnification per eyepiece — better for fine planetary detail.
Mount type
William Optics Zenithstar 61 has no mount — add a compatible mount before you can observe. Sky-Watcher Evostar 80ED + HEQ5 Pro 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
| Target | Sky-Watcher Evostar 80ED + HEQ5 Pro | William Optics Zenithstar 61 |
|---|---|---|
| Planets | ||
| Moon | Good 80mm aperture delivers sharp, colour-free craters and terminator detail; f/7.5 limits extreme magnification compared to longer focal length scopes | Moderate 61mm aperture shows craters and maria, but the short 360mm focal length limits useful magnification for fine detail |
| Saturn | Moderate Rings clearly visible and disc shows colour, but 600mm focal length keeps the image small — Cassini Division requires excellent seeing and high-power eyepieces | Challenging Rings visible as distinct structure, but 61mm aperture and 360mm focal length cannot reveal Cassini Division or banding |
| Jupiter | Moderate Main equatorial belts visible; 80mm aperture and 600mm focal length limit detail on the Great Red Spot and festoons | Challenging Disc and two main equatorial belts visible, but small aperture limits cloud detail and the short focal length keeps the image very small |
| Mars | Challenging Small orange disc visible at opposition; polar cap glimpsable in ideal conditions but surface albedo features are beyond this aperture | Not recommended Tiny orange disc at opposition; 61mm aperture and 360mm focal length cannot resolve surface features |
Deep sky | ||
| Orion Nebula (M42) | Excellent Wide 600mm field frames the full nebula and Running Man beautifully — bright enough to show structure visually and a superb imaging target | Good Wide field frames the full nebula and surrounding region; 61mm shows the bright core and inner nebulosity but lacks aperture for fainter outer structure visually |
| Andromeda Galaxy (M31) | Excellent 600mm focal length captures the full galaxy extent including companion galaxies; one of this scope's signature imaging targets | Excellent 360mm focal length captures the full extent of M31 and companion galaxies in a single field — ideal framing for imaging |
| Open clusters | Excellent Wide field perfectly frames the Double Cluster, Pleiades, and other large clusters with pin-sharp stars across the field | Excellent 360mm focal length gives wide true field, perfectly suited for large clusters like the Double Cluster, Pleiades, and Hyades |
| Globular clusters | Challenging 80mm aperture cannot resolve individual stars — M13 and M3 appear as fuzzy, unresolved glows | Challenging 61mm aperture shows fuzzy patches only; no star resolution possible even at the edges |
| Faint galaxies | Moderate Visually limited by 80mm aperture; however, with camera and stacked exposures, many faint galaxies are accessible photographically | Not recommended 61mm aperture gathers too little light to reveal faint galaxy detail visually |
| Milky Way / wide field | Good 600mm focal length is at the long end for sweeping Milky Way fields visually, but on camera the wide field and fast optics capture rich starfields well | Excellent 360mm focal length at f/5.9 delivers sweeping star fields — one of this scope's strengths both visually and for imaging |
Other | ||
| Double stars | Good Clean ED optics split well-separated doubles cleanly; Dawes limit at 80mm is ~1.45 arcsec, so tight pairs are out of reach | Moderate Dawes limit of ~1.9 arcseconds; wide pairs split cleanly but close doubles are beyond reach, and short focal length makes high-power splitting impractical |
| Astrophotography (deep sky) | Excellent HEQ5 Pro GoTo mount with tracking, 80mm ED optics at f/7.5 (f/6.3 with reducer), and massive payload headroom make this a benchmark widefield imaging rig | Not recommended No mount or tracking included; on a suitable equatorial mount this would rate Excellent — f/5.9, APO glass, and 360mm focal length are ideal for wide-field imaging |
| Astrophotography (planetary) | Challenging 80mm aperture and 600mm focal length produce a small planetary disc — limited detail even with lucky imaging techniques | Challenging 61mm aperture and 360mm focal length produce a very small planetary image scale; no tracking included |
| Large emission nebulae (imaging) | Not applicable | Excellent With a tracking mount, the wide f/5.9 field frames targets like the North America Nebula, Veil Nebula, and Heart/Soul complex superbly |
The real tradeoff
Both scopes are capable. The question is which one fits the way you actually observe.
Sky-Watcher Evostar 80ED + HEQ5 Pro
- You'll unbox this and have everything you need on the mount side to start imaging — polar align the HEQ5 Pro, bolt on the OTA, and you're shooting the same night, without agonising over which mount to pair with which tube.
- You'll appreciate the payload headroom: with a 3.2 kg OTA on a mount rated for 13.6 kg, you can pile on a guide scope, filter wheel, dew heater, and heavy camera without worrying about tracking degradation, and that margin is what makes guided 3–5 minute exposures routine rather than heroic.
- You'll pay for that completeness in setup time and bulk — every session starts with lugging a 10 kg+ mount head and tripod outside, levelling, polar aligning, and cabling up, so 'quick look' nights don't really exist with this rig.
William Optics Zenithstar 61
- You'll open a gorgeous box with a beautifully machined OTA inside — and then realise you still need a mount, a diagonal, an eyepiece, a camera, and a field flattener before you can do anything at all, so budget accordingly.
- You'll love how tiny and light this tube is when you're packing for a dark-sky trip — it pairs happily with a modest star tracker or small EQ mount, meaning your total travel rig can fit in a carry-on where the Evostar 80ED + HEQ5 would fill a car boot.
- You'll find the faster f/5.9 ratio and ultra-wide 360mm focal length let you frame truly enormous targets like the Heart and Soul or Veil Nebula complex in a single shot, but you're trading away the 80ED's extra aperture and focal length for that wider framing.
The dark side
Every scope has a personality. Here’s where each one gets difficult.
Sky-Watcher
Sky-Watcher Evostar 80ED + HEQ5 Pro
The £899 price gets you the OTA and mount but not the camera, guide scope, field flattener, or software you'll need to actually image — realistic first-light imaging cost is several hundred pounds higher.
The ED doublet is not a true triplet apochromat, so bright stars at high visual magnification show slight residual chromatic aberration — negligible in stacked images but visible at the eyepiece.
No field flattener is included, so without the separate 0.85× reducer/corrector your APS-C frames will show stretched, comatic stars toward the edges.
William Optics
William Optics Zenithstar 61
The OTA ships with no mount, no diagonal, and no eyepiece — at £499 you're buying an optical tube and nothing else, and the near-essential Flat6A field flattener adds roughly £250 on top.
At 61mm aperture, maximum useful magnification tops out around 120×, making planetary and lunar detail visibly inferior to the 80ED's already-modest 80mm — this is emphatically not a visual telescope.
Field curvature is noticeable at the edges of APS-C and full-frame sensors without the dedicated flattener, so imaging without that accessory produces noticeably soft corner stars.
Which is right for you?
Two different buyers. Two different right answers.
The automated deep-sky platform
Sky-Watcher · Sky-Watcher Evostar 80ED + HEQ5 Pro
You're ready to commit to learning astrophotography and you want a single purchase that gives you both a quality imaging OTA and a proven GoTo equatorial mount in one box. You don't mind spending 15–20 minutes on polar alignment each session, you're prepared to invest further in a camera and guide setup, and you want enough mount capacity to grow into heavier OTAs later. You value the 80mm aperture's extra light grasp and longer 600mm focal length for framing medium-sized targets like the Orion Nebula or Andromeda at a tighter, more detailed scale. This isn't for you if you want something quick to set up for casual visual observing — 80mm won't satisfy you on planets, and the HEQ5 is too heavy and fiddly for a spontaneous peek at the Moon.
The custom-rig optical tube
William Optics · William Optics Zenithstar 61
You already own a tracking mount — or know exactly which one you want — and you're looking for the lightest, most portable APO imaging tube you can throw in a bag for trips to dark-sky sites. You love ultra-wide framing and want to capture sprawling nebula complexes in single exposures, and you value the premium FPL-53 glass for clinically clean star colours. You're comfortable spending well beyond the £499 sticker price to assemble a complete imaging system around this OTA. This isn't for you if you're starting from zero and need a ready-to-use package, or if you want any meaningful visual capability — at 61mm, even the Moon feels like a tease compared to what a larger scope can show.
Our verdict
This comparison has a catch: the William Optics Zenithstar 61 is a bare optical tube. You cannot use it without a separate mount — which adds meaningful cost and complexity. The Sky-Watcher Evostar 80ED + HEQ5 Pro is a complete, ready-to-observe package.
For most buyers, the Sky-Watcher Evostar 80ED + HEQ5 Pro is the right choice — you can observe the same night it arrives. The William Optics Zenithstar 61 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 Sky-Watcher Evostar 80ED + HEQ5 Pro, without hesitation.
Sky-Watcher Evostar 80ED + HEQ5 Pro
View Sky-Watcher Evostar 80ED + HEQ5 Pro →William Optics Zenithstar 61
View William Optics Zenithstar 61 →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 | Sky-Watcher Evostar 80ED + HEQ5 Pro | William Optics Zenithstar 61 |
|---|---|---|
Apertureⓘ The most important spec — bigger = more light = better views | 80mm | 61mm |
Focal Length Longer = more magnification potential | 600mm | 360mm |
Focal Ratio Lower f-number = wider field of view; higher = more magnification per eyepiece | f/7.5 | f/5.9 |
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 ED glass, FMC on all air-to-glass surfaces | Fully multi-coated FMC on all air-to-glass surfaces, including ED element |
How do you point it?
| Spec | Sky-Watcher Evostar 80ED + HEQ5 Pro | William Optics Zenithstar 61 |
|---|---|---|
Mount Type The mechanical system that holds and moves the telescope | GoTo (Computerised) | 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 | Sky-Watcher Evostar 80ED + HEQ5 Pro | William Optics Zenithstar 61 |
|---|---|---|
Focuser Size 2" accepts wider eyepieces and gives better low-power views | 2" | 2" / 1.25" |
Focuser Type Rack-and-pinion is standard; Crayford and dual-speed are smoother | Crayford dual-speed (with 1.25" adapter) | Dual-speed Crayford 2" (10:1 reduction fine focus) |
Size & weight
| Spec | Sky-Watcher Evostar 80ED + HEQ5 Pro | William Optics Zenithstar 61 |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 2.2kg | 1.35kg |
Total Weight Full setup including mount — this is what you lug to the car | 22.5kg | — |
Tube Length | 600mm | 270mm |
Tube Material | Aluminium, white powder coat | Aluminium, anodised red |
What's in the box?
| Spec | Sky-Watcher Evostar 80ED + HEQ5 Pro | William Optics Zenithstar 61 |
|---|---|---|
Eyepieces Included eyepieces — more is better, but quality matters more than quantity | 25mm Super eyepiece | — |
Finder Scope Helps you locate areas of the sky before switching to the main eyepiece | 8x50 right-angle correct-image finder with illuminated reticle | — |
Diagonal Tilts the eyepiece 90° for comfortable viewing — useful on refractors |
Blue highlight: Sky-Watcher Evostar 80ED + HEQ5 Pro advantage · Amber highlight: William Optics Zenithstar 61 advantage · Greyed cells: equal or subjective.