Telescope Comparison
Sky-Watcher Esprit 100ED vs Sky-Watcher Esprit 80ED
The price gap is real. The question is whether the extra capability is worth it at your stage.
First light
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
Sky-Watcher · 80mm · £699
The custom-rig optical tube
- 80mm refractor — optical tube only, no mount included
- 480mm focal length at f/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
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. Sky-Watcher Esprit 80ED's shorter focal length gives a wider true field — better for large open clusters and extended nebulae.
Focal ratio
Sky-Watcher Esprit 100ED's faster f/5.5 delivers wider fields with any eyepiece — better for open clusters and large nebulae. Sky-Watcher Esprit 80ED's f/6 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)
Sky-Watcher Esprit 80ED'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 | Sky-Watcher Esprit 100ED | Sky-Watcher Esprit 80ED |
|---|---|---|
| Planets | ||
| Moon | 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 | Good Clean, chromatic-aberration-free views through the triplet ED optics, but 80mm aperture and short focal length limit high-magnification fine detail. |
| Saturn | Good Rings clearly separated, Cassini Division visible in good seeing; 550mm focal length limits image scale at the eyepiece | Moderate Rings visible and well-defined, but 480mm focal length requires very short eyepieces to reach useful magnification — Cassini Division only in excellent seeing. |
| Jupiter | Good Two main cloud belts and GRS visible; 100mm aperture resolves belt detail but the short focal length caps useful magnification | Moderate Main cloud belts visible, but 80mm aperture and 480mm focal length limit the detail and magnification ceiling. |
| Mars | Moderate Disc and polar cap visible at opposition; 100mm and 550mm focal length are limiting for surface albedo features | Challenging Small disc visible near opposition, but 80mm aperture is insufficient to reliably show surface features or polar cap. |
Deep sky | ||
| Orion Nebula (M42) | Excellent 100mm gathers ample light, 550mm frames the full nebula with surrounding nebulosity; f/5.5 rewards both visual and imaging use | Excellent 80mm aperture exceeds the threshold and the 480mm f/6 optics frame the full nebula extent with rich wide-field context — superb visually and for imaging. |
| Andromeda Galaxy (M31) | Excellent 550mm captures the full extent of M31 including companion galaxies; 100mm aperture shows outer halo hints visually | Excellent 480mm focal length captures the full 3°+ extent of the galaxy including companion galaxies; ideal framing for both visual sweeping and imaging. |
| Open clusters | Excellent 550mm focal length provides generous framing — the Double Cluster, Pleiades, and similar targets are beautifully presented | Excellent 480mm focal length provides a wide true field — the Double Cluster, Pleiades, and Beehive are beautifully framed. |
| Globular clusters | Moderate M13 and M5 appear granular with hints of edge resolution; core remains unresolved at 100mm | Challenging 80mm aperture cannot resolve individual stars — globulars appear as fuzzy, unresolved patches. |
| Faint galaxies | Moderate 100mm shows brighter Messier galaxies as fuzzy patches; NGC targets require dark skies and are at the limit visually | Moderate Many galaxies detectable visually as faint smudges; long-exposure imaging through a suitable mount recovers far more, but aperture is the limiting factor. |
| Milky Way / wide field | Good 550mm is slightly long for sweeping Milky Way panoramas but still delivers rich star fields; excellent for targeted regions like Cygnus | Excellent 480mm focal length at f/6 delivers sweeping star fields visually and wide rich Milky Way frames for imaging. |
Other | ||
| Double stars | 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 | Good Clean APO optics and 80mm aperture resolve wide and moderate doubles crisply, though close pairs under 1.5 arcseconds are beyond the Dawes limit. |
| Astrophotography (deep sky) | 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 | Not recommended No mount included — the OTA is designed for deep-sky imaging, but without an equatorial tracking mount it cannot be rated. Paired with an HEQ5 or similar, performance would be Excellent. |
| Astrophotography (planetary) | Moderate 100mm aperture is workable with a Barlow and planetary camera, but 550mm native focal length requires significant amplification; needs a tracking mount | Challenging 80mm aperture and 480mm focal length yield a small planetary image scale; even with a 3× Barlow the effective focal length is modest for planetary work. |
| Emission nebulae (imaging) | 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 | Excellent Fast f/6 focal ratio and wide field are ideal for large emission nebulae like the North America, Heart, and Rosette when paired with a narrowband filter and tracking mount. |
| Galaxy groups (imaging) | Good 550mm frames targets like the Leo Triplet and Markarian's Chain well on APS-C; 100mm gathers enough light for reasonable exposure times | Not applicable |
The real tradeoff
Both scopes are capable. The question is which one fits the way you actually observe.
Sky-Watcher Esprit 100ED
- You'll gather 56% more light than the 80ED, which translates directly into shorter sub-exposures or cleaner data on faint targets — that galaxy group in Leo that needed four hours with the 80mm might only need two and a half here.
- You'll also notice the extra 70mm of focal length (550mm vs 480mm) gives you a tighter framing that better fills the sensor on medium-scale targets like the Rosette or Leo Triplet, but your fully loaded imaging train will push toward 6–7kg, so you need to budget for a mount that can handle that — an HEQ5 is the realistic minimum.
- If you do put an eyepiece in on a night when conditions are right, 100mm of triplet APO gives you genuinely satisfying lunar and planetary snapshots — Jupiter's festoons, Saturn's Cassini division — in a way the 80mm simply can't match.
Sky-Watcher Esprit 80ED
- You'll save £400 on the OTA alone, and because the scope is lighter, you can get away with a less expensive mount — the total system cost difference between these two setups can easily exceed £800.
- You'll frame wider fields — over 4° on full-frame — which means the North America and Pelican complex or the Heart and Soul pair fit comfortably in a single shot without mosaics, targets that start to get cropped on the 100ED.
- You'll spend less time fighting balance and flexure because the 80ED is noticeably lighter on your mount, and on a portable setup you'll appreciate that every session when you're hauling gear out to a dark site.
The dark side
Every scope has a personality. Here’s where each one gets difficult.
Sky-Watcher
Sky-Watcher Esprit 100ED
At £1,099 for the OTA alone — no mount, no finder, no diagonal, no eyepiece — a realistic imaging-ready system typically runs £2,500–£3,000+, making this a serious financial commitment before you capture a single photon.
Some narrowband filters produce halos or uneven illumination at f/5.5, particularly across full-frame sensors — you may need to crop or switch to APS-C for clean Ha or OIII work.
The integrated field flattener demands exactly 55mm of back-focus; get the spacing wrong by even a couple of millimetres and your edge stars will stretch into comets, which means fiddling with spacer rings until it's right.
Sky-Watcher
Sky-Watcher Esprit 80ED
80mm of aperture means significantly longer total integration times on faint targets compared to the 100ED — you're fighting the physics of a smaller light bucket, and on dim galaxies you'll feel it.
Reaching useful planetary magnification at 480mm focal length would require a 2.4mm eyepiece to hit 200×, which is essentially impractical — this scope has almost no meaningful visual planetary capability.
Like the 100ED, the field flattener is designed for Sky-Watcher's 55mm back-focus spacing, and incorrect spacing introduces field curvature — but at f/6, you have slightly less tolerance for error than you might expect.
Which is right for you?
Two different buyers. Two different right answers.
The custom-rig optical tube
Sky-Watcher · Sky-Watcher Esprit 100ED
You've already been imaging with an 80mm class refractor and you know exactly what you're doing — you understand guiding, back-focus spacing, and you own or plan to buy a mount rated for 7kg+ imaging payloads. You want to step up in light-gathering power and resolution without jumping to a heavy Newtonian, and you're willing to spend £2,500+ on a complete system. You shoot medium- to large-scale deep-sky targets and want the extra aperture to cut your integration times and pull more detail from faint structure. This is not your first scope, and it shouldn't be.
The custom-rig optical tube
Sky-Watcher · Sky-Watcher Esprit 80ED
You're an intermediate astrophotographer building your first dedicated imaging rig, or you're a seasoned imager who wants the lightest, widest-field APO triplet you can get for portable dark-site work. You shoot big emission nebulae and sweeping Milky Way fields more than small galaxies, and you'd rather put the £400 you save on the OTA toward better filters or a star tracker upgrade. You accept that 80mm means longer integration times on faint targets, because for you, the lighter weight, wider field, and lower total system cost matter more than raw aperture.
Our verdict
At £699 versus £1,099, the Sky-Watcher Esprit 100ED costs 57% more. It delivers 20mm more aperture — a real and visible advantage on faint targets.
If budget is a genuine constraint, the Sky-Watcher Esprit 80ED will make you a happy observer. The Sky-Watcher Esprit 100ED'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 Sky-Watcher Esprit 80ED, use it for a year, then upgrade knowing exactly what you want.
Sky-Watcher Esprit 100ED
View Sky-Watcher Esprit 100ED →Sky-Watcher Esprit 80ED
View Sky-Watcher Esprit 80ED →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 Esprit 100ED | Sky-Watcher Esprit 80ED |
|---|---|---|
Apertureⓘ The most important spec — bigger = more light = better views | 100mm | 80mm |
Focal Length Longer = more magnification potential | 550mm | 480mm |
Focal Ratio Lower f-number = wider field of view; higher = more magnification per eyepiece | f/5.5 | f/6 |
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 triplet with FMC on all air-to-glass surfaces | Fully multi-coated ED triplet with FMC on all air-to-glass surfaces |
How do you point it?
| Spec | Sky-Watcher Esprit 100ED | Sky-Watcher Esprit 80ED |
|---|---|---|
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 | Sky-Watcher Esprit 100ED | Sky-Watcher Esprit 80ED |
|---|---|---|
Focuser Size 2" accepts wider eyepieces and gives better low-power views | 2" | 2" |
Focuser Type Rack-and-pinion is standard; Crayford and dual-speed are smoother | Dual-speed Crayford (10:1 reduction, with 1.25" adapter) | Dual-speed Crayford (10:1 reduction, with 1.25" adapter) |
Size & weight
| Spec | Sky-Watcher Esprit 100ED | Sky-Watcher Esprit 80ED |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 3.9kg | 2.55kg |
Tube Length | 535mm | 450mm |
Tube Material | Aluminium, white powder coat | Aluminium, white powder coat |
What's in the box?
| Spec | Sky-Watcher Esprit 100ED | Sky-Watcher Esprit 80ED |
|---|---|---|
Diagonal Tilts the eyepiece 90° for comfortable viewing — useful on refractors |
Blue highlight: Sky-Watcher Esprit 100ED advantage · Amber highlight: Sky-Watcher Esprit 80ED advantage · Greyed cells: equal or subjective.