Telescope Comparison
Askar 80PHQ vs William Optics Zenithstar 61
The specs are close. The experience isn't.
First light
Askar · 80mm · £799
The custom-rig optical tube
- 80mm refractor — optical tube only, no mount included
- 448mm focal length at f/5.6
- 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
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
Askar 80PHQ 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
Askar 80PHQ'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
Askar 80PHQ's faster f/5.6 delivers wider fields with any eyepiece — better for open clusters and large nebulae. William Optics Zenithstar 61's f/5.9 provides more magnification per eyepiece — better for fine planetary detail.
Mount type
Neither scope includes a mount — both require a separate purchase before you can observe.
Weight (OTA)
William Optics Zenithstar 61's optical tube is 1.4kg lighter. Relevant if you plan to use it on multiple mounts or carry the tube to dark-sky sites separately.
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 | Askar 80PHQ | William Optics Zenithstar 61 |
|---|---|---|
| Planets | ||
| Moon | Excellent 80mm aperture delivers sharp lunar detail; short focal length limits magnification but crater fields and terminator are crisp | Moderate 61mm aperture shows craters and maria, but the short 360mm focal length limits useful magnification for fine detail |
| Saturn | Good Rings clearly visible at modest magnification; 448mm focal length limits high-power planetary detail | Challenging Rings visible as distinct structure, but 61mm aperture and 360mm focal length cannot reveal Cassini Division or banding |
| Jupiter | Good Main cloud belts and Galilean moons visible, but the short focal length constrains useful magnification | 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 disc visible at opposition; 80mm aperture and 448mm focal length insufficient to resolve surface features reliably | Not recommended Tiny orange disc at opposition; 61mm aperture and 360mm focal length cannot resolve surface features |
Deep sky | ||
| Orion Nebula (M42) | Excellent Bright target framed beautifully by the wide field; f/5.6 speed and sub-600mm focal length show full nebula extent | 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 448mm focal length captures the full extent of M31 including outer halo; 80mm aperture adequate for the bright core and dust lanes | 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 at 448mm frames large clusters like the Double Cluster, Pleiades, and Hyades superbly | Excellent 360mm focal length gives wide true field, perfectly suited for large clusters like the Double Cluster, Pleiades, and Hyades |
| Globular clusters | Moderate 80mm aperture shows bright globulars like M13 as granular but unresolved fuzzy patches | Challenging 61mm aperture shows fuzzy patches only; no star resolution possible even at the edges |
| Faint galaxies | Moderate 80mm aperture detects brighter Messier galaxies as smudges; insufficient light grasp for dim NGC targets visually | Not recommended 61mm aperture gathers too little light to reveal faint galaxy detail visually |
| Milky Way / wide field | Excellent 448mm focal length at f/5.6 — ideal for sweeping rich star fields and Milky Way structure | 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 80mm resolves wider doubles cleanly; the fast f/5.6 focal ratio is less ideal than a long-FL refractor for tight pairs | 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) | Not recommended OTA only with no mount — requires a separate equatorial or GoTo mount for any deep-sky imaging; on a suitable mount this would rate Excellent | 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 448mm focal length undersized for planetary imaging; a Barlow helps but cannot overcome the aperture limit | Challenging 61mm aperture and 360mm focal length produce a very small planetary image scale; no tracking included |
| Wide-field emission nebulae (imaging) | Excellent Fast f/5.6 quad APO with integrated flattener is purpose-built for targets like the Veil, North America, and Rosette Nebulae on a suitable mount | Not applicable |
| 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.
Askar 80PHQ
- You'll spend your setup time nailing the 55mm back-focus distance rather than bolting on an external field flattener — the integrated quadruplet design means once you've got the spacing right, stars are pinpoint across a full-frame sensor without buying a separate corrector.
- You'll find yourself reaching for bigger, fainter targets — the 80mm aperture pulls in noticeably more light than the ZS61, which means shorter total integration times on emission nebulae and the confidence to chase dimmer galaxy groups like the Leo Triplet without stacking all night.
- You'll need a sturdier equatorial mount to carry the heavier OTA and camera payload, and at £799 before mount, camera, and guide scope, your total system cost climbs fast — but you're rewarded with an imaging platform that won't leave you wishing for more aperture after six months.
William Optics Zenithstar 61
- You'll throw this on a lightweight star tracker or modest EQ mount and be imaging within minutes — the tiny, featherweight tube is the closest thing astrophotography has to a grab-and-go setup, and it's a genuine travel scope in a way the 80PHQ isn't.
- You'll budget an extra ~£250 for the Flat6A field flattener almost immediately, because without it you'll see obvious star elongation at the edges of an APS-C sensor — so your real cost of entry is closer to £750, narrowing the gap with the 80PHQ.
- You'll frame enormous targets like the Heart and Soul pair or the full Cygnus Loop beautifully at 360mm, but when you move to smaller objects or try to tease faint detail from galaxy arms, you'll feel the 61mm aperture running out of steam well before the Askar does.
The dark side
Every scope has a personality. Here’s where each one gets difficult.
Askar
Askar 80PHQ
Sold as OTA only with no mount, finder, diagonal, or eyepiece — total system cost for a working imaging rig can easily double or triple the £799 sticker price.
Getting the back-focus spacing exactly right (~55mm) is critical; incorrect spacing introduces field curvature and elongated corner stars, which can waste an entire night's data if you don't catch it.
Some users report the stock focuser can struggle under heavy camera payloads, potentially requiring an aftermarket upgrade that adds further cost.
William Optics
William Optics Zenithstar 61
The Flat6A field flattener is a near-essential £250 add-on for imaging — without it, field curvature produces visibly distorted stars at APS-C and full-frame sensor edges, so the true imaging-ready price is closer to £750.
At 61mm aperture, visual performance is severely limited — you're looking at roughly 1.9 arcsecond resolution, which means planetary detail barely goes beyond confirming Saturn's rings and Jupiter's main belts.
Like the 80PHQ, this is OTA only with no mount, diagonal, or eyepiece included — a beginner expecting to look through it on the first night will be disappointed and significantly out of pocket before they can use it.
Which is right for you?
Two different buyers. Two different right answers.
The custom-rig optical tube
Askar · Askar 80PHQ
You're an intermediate astrophotographer ready to invest in a proper imaging rig — equatorial mount, guide scope, dedicated camera — and you want an OTA that won't hold you back on full-frame sensors. You value the integrated field flattener because you've already lost patience wrestling with back-focus spacers on a separate corrector. You're happy to carry slightly more weight for a meaningful jump in light grasp over the smallest APO refractors, and your target list includes not just the showpiece nebulae but fainter galaxy groups and narrowband projects where every millimetre of aperture counts. This isn't for you if you want a grab-and-go visual scope, or if you're building your first astrophotography setup and don't yet own a capable equatorial mount.
The custom-rig optical tube
William Optics · William Optics Zenithstar 61
You're building a lightweight, portable imaging setup — maybe pairing it with a star tracker for trips to dark-sky sites — and you want the smallest, lightest quality APO you can find. You're shooting wide-field Milky Way mosaics, big nebulae, and constellation-scale star fields, and you accept that the 61mm aperture means longer integrations on anything faint. You're comfortable buying the Flat6A flattener as part of the package cost and you don't expect to use this scope visually in any serious way. This isn't for you if you want an all-in-one imaging and visual telescope, or if you're planning to shoot smaller deep-sky targets where the Zenithstar's limited aperture and resolution will leave you wanting more.
Our verdict
At £499 versus £799, the Askar 80PHQ costs 60% more. It delivers 19mm more aperture — a real and visible advantage on faint targets.
If budget is a genuine constraint, the William Optics Zenithstar 61 will make you a happy observer. The Askar 80PHQ's optical advantage on faint targets is real and you are unlikely to regret it if you can stretch. If I had to choose without knowing your situation: start with the William Optics Zenithstar 61, use it for a year, then upgrade knowing exactly what you want.
Askar 80PHQ
View Askar 80PHQ →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 | Askar 80PHQ | William Optics Zenithstar 61 |
|---|---|---|
Apertureⓘ The most important spec — bigger = more light = better views | 80mm | 61mm |
Focal Length Longer = more magnification potential | 448mm | 360mm |
Focal Ratio Lower f-number = wider field of view; higher = more magnification per eyepiece | f/5.6 | 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 PHQ quadruplet on all surfaces | Fully multi-coated FMC on all air-to-glass surfaces, including ED element |
How do you point it?
| Spec | Askar 80PHQ | William Optics Zenithstar 61 |
|---|---|---|
Mount Type The mechanical system that holds and moves the telescope | None (OTA only) | 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 | Askar 80PHQ | William Optics Zenithstar 61 |
|---|---|---|
Focuser Size 2" accepts wider eyepieces and gives better low-power views | 2" / 1.25" | 2" / 1.25" |
Focuser Type Rack-and-pinion is standard; Crayford and dual-speed are smoother | Dual-speed Crayford 2" (with 1.25" adapter) | Dual-speed Crayford 2" (10:1 reduction fine focus) |
Size & weight
| Spec | Askar 80PHQ | William Optics Zenithstar 61 |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 2.8kg | 1.35kg |
Tube Length | 360mm | 270mm |
Tube Material | Aluminium | Aluminium, anodised red |
What's in the box?
| Spec | Askar 80PHQ | William Optics Zenithstar 61 |
|---|---|---|
Diagonal Tilts the eyepiece 90° for comfortable viewing — useful on refractors |
Blue highlight: Askar 80PHQ advantage · Amber highlight: William Optics Zenithstar 61 advantage · Greyed cells: equal or subjective.