Telescope Comparison
Askar 80PHQ vs Sky-Watcher Esprit 100ED
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
Sky-Watcher · 100mm · £1,099
The custom-rig optical tube
- 100mm refractor — optical tube only, no mount included
- 550mm focal length at f/5.5
- 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 Esprit 100ED gathers 1.6× 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 Esprit 100ED's longer focal length reaches higher magnification with the same eyepiece — better reach for planetary detail. Askar 80PHQ's shorter focal length gives a wider true field — better for large open clusters and extended nebulae.
Focal ratio
Same focal ratio — the same eyepiece gives equivalent magnification and true field in both scopes.
Mount type
Neither scope includes a mount — both require a separate purchase before you can observe.
Weight (OTA)
Askar 80PHQ's optical tube is 1.1kg 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 | Sky-Watcher Esprit 100ED |
|---|---|---|
| Planets | ||
| Moon | Excellent 80mm aperture delivers sharp lunar detail; short focal length limits magnification but crater fields and terminator are crisp | Excellent 100mm aperture delivers sharp crater detail and clean terminator views; the fast focal ratio means lower magnification per eyepiece but detail is still crisp |
| Saturn | Good Rings clearly visible at modest magnification; 448mm focal length limits high-power planetary detail | Good Rings clearly separated, Cassini Division visible in good seeing; 550mm focal length limits image scale at the eyepiece |
| Jupiter | Good Main cloud belts and Galilean moons visible, but the short focal length constrains useful magnification | Good Two main cloud belts and GRS visible; 100mm aperture resolves belt detail but the short focal length caps useful magnification |
| Mars | Challenging Small disc visible at opposition; 80mm aperture and 448mm focal length insufficient to resolve surface features reliably | Moderate Disc and polar cap visible at opposition; 100mm and 550mm focal length are limiting for surface albedo 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 | Excellent 100mm gathers ample light, 550mm frames the full nebula with surrounding nebulosity; f/5.5 rewards both visual and imaging use |
| 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 550mm captures the full extent of M31 including companion galaxies; 100mm aperture shows outer halo hints visually |
| Open clusters | Excellent Wide field at 448mm frames large clusters like the Double Cluster, Pleiades, and Hyades superbly | Excellent 550mm focal length provides generous framing — the Double Cluster, Pleiades, and similar targets are beautifully presented |
| Globular clusters | Moderate 80mm aperture shows bright globulars like M13 as granular but unresolved fuzzy patches | Moderate M13 and M5 appear granular with hints of edge resolution; core remains unresolved at 100mm |
| Faint galaxies | Moderate 80mm aperture detects brighter Messier galaxies as smudges; insufficient light grasp for dim NGC targets visually | Moderate 100mm shows brighter Messier galaxies as fuzzy patches; NGC targets require dark skies and are at the limit visually |
| Milky Way / wide field | Excellent 448mm focal length at f/5.6 — ideal for sweeping rich star fields and Milky Way structure | Good 550mm is slightly long for sweeping Milky Way panoramas but still delivers rich star fields; excellent for targeted regions like Cygnus |
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 | Good 100mm resolves down to about 1.2 arcsec; chromatic correction is excellent but the fast focal ratio makes splitting tight pairs trickier than in a long-focus refractor |
| 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 included — on a suitable equatorial GoTo mount this scope would rate Excellent (f/5.5, 100mm, flat field to full-frame), but as sold it cannot track |
| Astrophotography (planetary) | Challenging 80mm aperture and 448mm focal length undersized for planetary imaging; a Barlow helps but cannot overcome the aperture limit | Moderate 100mm aperture is workable with a Barlow and planetary camera, but 550mm native focal length requires significant amplification; needs a tracking mount |
| 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 |
| Emission nebulae (imaging) | Not applicable | Excellent Fast f/5.5 ratio and 550mm focal length are ideal for large emission targets like the Veil, Rosette, and Heart Nebulae on APS-C or full-frame sensors |
| Galaxy groups (imaging) | Not applicable | Good 550mm frames targets like the Leo Triplet and Markarian's Chain well on APS-C; 100mm gathers enough light for reasonable exposure times |
The real tradeoff
Both scopes are capable. The question is which one fits the way you actually observe.
Askar 80PHQ
- You'll mount this on a lighter, cheaper equatorial setup — the compact 80mm OTA means something like an HEQ5 carries it with headroom to spare, and you can realistically pack the whole rig into a carry-on for dark-sky trips.
- You'll reach for wide, dramatic targets — the 448mm focal length at f/5.6 gives you a huge 4.6° × 3.1° field on full-frame, so you're framing entire nebula complexes in single shots and accumulating Ha and OIII data fast without needing marathon integration times.
- You'll rarely, if ever, put an eyepiece in this scope — with only 80mm of aperture and a short focal length, visual sessions are an afterthought, and you'll accept that every pound you spent here went toward imaging performance, not double-duty versatility.
Sky-Watcher Esprit 100ED
- You'll need a more substantial mount — fully loaded with camera, guidescope, and cables the payload approaches 6–7kg, so you're looking at an EQ6-R class mount or equivalent, which adds significantly to cost and portability trade-offs.
- You'll gain 56% more light-gathering area over the 80PHQ and a longer 550mm focal length, which means fainter galaxy detail emerges sooner in your subs and smaller targets like galaxy groups and planetary nebulae have more image scale to work with.
- You'll occasionally enjoy a genuinely satisfying visual detour — the 100mm aperture shows you a sharp Moon, cleanly split Saturn's rings, and resolved Trapezium stars, giving you something the 80PHQ simply can't match when you want a quick look before the imaging run starts.
The dark side
Every scope has a personality. Here’s where each one gets difficult.
Askar
Askar 80PHQ
The 80mm aperture is the hard ceiling — you'll need longer total integration times to pull faint galaxy arms and outer nebula structure compared to the Esprit 100ED's 25% larger aperture, and no amount of processing will recover photons that never arrived.
Back-focus spacing must be exactly 55mm to get the flat field the quadruplet design promises; get it wrong by even a couple of millimetres and you'll see field curvature and elongated corner stars that undermine the whole point of buying a quad APO.
Some users report the stock focuser flexes under heavier camera payloads — if you're running a full-frame cooled camera with a filter wheel, budget for a potential aftermarket focuser upgrade.
Sky-Watcher
Sky-Watcher Esprit 100ED
Total system cost escalates fast — the £1,099 OTA needs a mount, guidescope, and accessories that typically push the complete imaging rig to £2,500–£3,000+, making this a serious financial commitment before you capture a single photon.
At f/5.5 with full-frame sensors, some narrowband filters produce halos or uneven illumination across the field; you may need to crop or switch to APS-C-sized sensors for clean narrowband work.
Like the 80PHQ, back-focus must hit exactly 55mm for flat edges — but the heavier total payload on the focuser means you're also managing more accessories in that spacing chain, increasing the chance of getting it wrong.
Which is right for you?
Two different buyers. Two different right answers.
The custom-rig optical tube
Askar · Askar 80PHQ
You're a dedicated deep-sky imager who prioritises portability, fast acquisition, and wide-field framing above all else. You already own or plan to buy a mid-range equatorial mount, and you want the lightest, most compact APO that delivers flat, corrected fields across a full-frame sensor without fussing with external flatteners. You have zero interest in visual observing and you're comfortable spending your budget on imaging accessories rather than a larger aperture. If you're chasing sweeping Milky Way mosaics, full nebula complexes in single frames, and dark-sky travel setups you can carry on a plane, the 80PHQ is built exactly for you. This isn't for you if you want any visual versatility, if you need more light grasp for faint galaxies, or if you're a beginner expecting a complete ready-to-use package.
The custom-rig optical tube
Sky-Watcher · Sky-Watcher Esprit 100ED
You're stepping up from an 80mm-class refractor and you want more light-gathering power and image scale without jumping to a heavy, unwieldy Newtonian. You're willing to invest in a heavier mount and a higher total system cost because you've already learned the basics and you know that 25% more aperture translates directly into richer data on galaxies and faint nebulae. You also appreciate that on the occasional night when conditions aren't ideal for imaging, you can drop in an eyepiece and enjoy genuinely rewarding views of the Moon, planets, and bright deep-sky objects. This isn't for you if portability is paramount, if your mount can't handle 6–7kg of imaging payload, or if you're trying to keep the total budget under £1,500.
Our verdict
These two are closer than most comparisons on this site. The spec differences are genuine — mount type, focal ratio — but neither is the wrong answer for a typical observer starting out.
If I had to choose between them: the Askar 80PHQ is the scope most people will be using regularly six months from now. The Sky-Watcher Esprit 100ED rewards you more once you know what you're doing — it's worth revisiting after your first year.
Askar 80PHQ
View Askar 80PHQ →Sky-Watcher Esprit 100ED
View Sky-Watcher Esprit 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 | Askar 80PHQ | Sky-Watcher Esprit 100ED |
|---|---|---|
Apertureⓘ The most important spec — bigger = more light = better views | 80mm | 100mm |
Focal Length Longer = more magnification potential | 448mm | 550mm |
Focal Ratio Lower f-number = wider field of view; higher = more magnification per eyepiece | f/5.6 | f/5.5 |
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 ED triplet with FMC on all air-to-glass surfaces |
How do you point it?
| Spec | Askar 80PHQ | Sky-Watcher Esprit 100ED |
|---|---|---|
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 | Sky-Watcher Esprit 100ED |
|---|---|---|
Focuser Size 2" accepts wider eyepieces and gives better low-power views | 2" / 1.25" | 2" |
Focuser Type Rack-and-pinion is standard; Crayford and dual-speed are smoother | Dual-speed Crayford 2" (with 1.25" adapter) | Dual-speed Crayford (10:1 reduction, with 1.25" adapter) |
Size & weight
| Spec | Askar 80PHQ | Sky-Watcher Esprit 100ED |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 2.8kg | 3.9kg |
Tube Length | 360mm | 535mm |
Tube Material | Aluminium | Aluminium, white powder coat |
What's in the box?
| Spec | Askar 80PHQ | Sky-Watcher Esprit 100ED |
|---|---|---|
Diagonal Tilts the eyepiece 90° for comfortable viewing — useful on refractors |
Blue highlight: Askar 80PHQ advantage · Amber highlight: Sky-Watcher Esprit 100ED advantage · Greyed cells: equal or subjective.