Telescope Comparison
Explore Scientific 12" Dobsonian vs Sky-Watcher Skyliner 350P
The specs are close. The experience isn't.
First light
Explore Scientific · 305mm · £999
The maximum-aperture visual reflector
- 305mm Newtonian on a floor-standing Dobsonian alt-az rocker box
- Good for: full visual programme — planets, Moon, globular clusters, galaxies, nebulae
- No alignment required — set up and observe in under 10 minutes
- No motorised tracking — targets drift at high magnification as Earth rotates
- 34kg total — designed for a fixed garden or regular dark-sky site, not casual transport
Sky-Watcher · 355mm · £1,099
The maximum-aperture visual reflector
- 355mm Newtonian on a floor-standing Dobsonian alt-az rocker box
- Good for: full visual programme — planets, Moon, globular clusters, galaxies, nebulae
- No alignment required — set up and observe in under 10 minutes
- No motorised tracking — targets drift at high magnification as Earth rotates
- 58kg total — designed for a fixed garden or regular dark-sky site, not casual transport
The full picture
The numbers that separate these two scopes — and what they mean at the eyepiece.
Aperture
Sky-Watcher Skyliner 350P gathers 1.4× 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 Skyliner 350P's longer focal length reaches higher magnification with the same eyepiece — better reach for planetary detail. Explore Scientific 12" Dobsonian's shorter focal length gives a wider true field — better for large open clusters and extended nebulae.
Focal ratio
Sky-Watcher Skyliner 350P's faster f/4.51 delivers wider fields with any eyepiece — better for open clusters and large nebulae. Explore Scientific 12" Dobsonian's f/4.99 provides more magnification per eyepiece — better for fine planetary detail.
Mount type
Same mount type — setup experience and ergonomics will be similar. Differences lie in build quality and included accessories.
Weight (OTA)
Explore Scientific 12" Dobsonian's optical tube is 14.0kg lighter. Relevant if you plan to use it on multiple mounts or carry the tube to dark-sky sites separately.
Optical design
Same optical design — differences between these scopes come from aperture, mount, and focal ratio.
At the eyepiece
| Target | Explore Scientific 12" Dobsonian | Sky-Watcher Skyliner 350P |
|---|---|---|
| Planets | ||
| Moon | Excellent 305mm aperture delivers overwhelming lunar detail — sub-kilometre crater features, rilles, and shadow play at high magnification | Excellent 355mm aperture delivers overwhelming lunar detail — rilles, dome fields, and tiny craterlets visible at high magnification in steady seeing |
| Saturn | Excellent 305mm aperture and 1524mm focal length show the Cassini Division cleanly, globe banding, and multiple moons | Excellent Cassini Division, ring structure, and subtle cloud banding on the disc; 1600mm focal length supports high magnification |
| Jupiter | Excellent Multiple cloud belts, festoons, the Great Red Spot, and moon shadow transits visible in steady seeing | Excellent Festoons, barges, and fine belt structure visible; GRS detail and moon shadow transits are striking at 200x+ |
| Mars | Excellent 305mm aperture at 1524mm focal length reveals dark albedo features and polar caps at opposition | Excellent 355mm aperture and 1600mm focal length exceed the rubric thresholds — surface albedo features, polar caps, and limb phenomena at opposition |
Deep sky | ||
| Orion Nebula (M42) | Excellent Massive light grasp shows layered nebulosity with hints of colour; Trapezium E and F stars visible on good nights | Excellent Massive aperture reveals layered nebulosity and faint outer wings; Trapezium E and F stars resolved — though the 1600mm focal length shows the core region more than the full extent |
| Andromeda Galaxy (M31) | Moderate 1524mm focal length crops the 3° extent to the bright core and inner dust lanes — full halo is beyond the field of view | Moderate 1600mm focal length crops the outer halo heavily — you see the bright core and inner dust lanes but not the full 3° extent |
| Open clusters | Moderate Long focal length limits the field of view — larger clusters like the Double Cluster overfill the field, though compact clusters are striking | Moderate 1600mm focal length means large clusters like the Double Cluster or Pleiades overfill the field; compact clusters like M11 and M37 fare better |
| Globular clusters | Excellent 305mm resolves individual stars across the full extent of clusters like M13 and M92, including their dense cores | Excellent 355mm resolves individual stars well into the core of M13, M5, and M22 — even dimmer globulars like M56 show granularity |
| Faint galaxies | Excellent 305mm of aperture reveals spiral arms in M51, dust lanes in edge-on galaxies, and populates the Virgo Cluster with dozens of members | Excellent The scope's strongest suit — 355mm pulls spiral arm hints from M51, reveals the dust lane in NGC 891, and makes Virgo Cluster galaxies accessible by the dozen |
| Milky Way / wide field | Not recommended 1524mm focal length produces far too narrow a field for sweeping Milky Way star fields | Not recommended 1600mm focal length and minimum magnification ~50x make sweeping star fields impractical — use binoculars instead |
Other | ||
| Double stars | Excellent 305mm aperture gives a Dawes limit of ~0.38 arcseconds; long focal length supports high magnification for tight pairs | Excellent 355mm gives a Dawes limit around 0.33 arcsec; tight doubles like Porrima and Epsilon Boötis split cleanly when collimation and seeing cooperate |
| Astrophotography (planetary) | Good 305mm aperture and 1524mm focal length suit high-resolution planetary video capture, though manual tracking limits frame consistency | Good 355mm aperture and 1600mm focal length suit high-resolution planetary imaging with a high-speed camera, but manual alt-az tracking limits capture run length |
The real tradeoff
Both scopes are capable. The question is which one fits the way you actually observe.
Explore Scientific 12" Dobsonian
- You'll wrestle a 15–17kg tube and a rocker box into your car, but it fits in a regular car boot — you can realistically do a solo dark-site run without needing a van or a friend on standby.
- You'll see spiral arms in M51, resolve M13 to its core, and pull four or more Jovian cloud belts on a good night — 305mm is the sweet spot where deep-sky objects show genuine structure without the logistics of a truly enormous scope.
- You'll spend less time cooling down than the 350P (30–60 minutes versus 45–60+), and collimation at f/5 is slightly more forgiving than f/4.5 — your evenings start producing sharp views a bit sooner.
Sky-Watcher Skyliner 350P
- You'll need a van or a large estate car and ideally a second pair of hands — at 58kg total, this isn't a scope you casually toss in the car, it's a scope you plan an evening around moving.
- You'll see objects the 12-inch simply can't deliver: the Antennae galaxies show real structure, Palomar-class globulars become accessible, and the Trapezium splits cleanly into all six components — that extra 50mm of aperture buys genuinely fainter targets, not just marginally brighter ones.
- You'll be nudging the scope constantly at high power because objects drift through the field fast with no tracking, and you'll need a light shroud for the open truss tube unless you're at a genuinely dark site — this scope demands you manage it, not just point it.
The dark side
Every scope has a personality. Here’s where each one gets difficult.
Explore Scientific
Explore Scientific 12" Dobsonian
At f/5, coma is visible toward the edges of wide-field eyepieces — budget an extra £100–200 for a coma corrector or accept soft stars at the field periphery.
Collimation must be checked before every session and is critical at this focal ratio; without a collimation tool and the habit of using it, you'll lose the planetary sharpness this aperture should deliver.
No tracking or GoTo means you're manually finding and following every target — at 305mm the field of view is narrow enough that nudging to keep objects centred at high power becomes a constant task.
Sky-Watcher
Sky-Watcher Skyliner 350P
The total weight approaches 58kg — this scope effectively requires ground-floor storage and a van or large estate car, ruling it out for anyone in a flat or with only a hatchback.
At f/4.5, coma is severe at the field edge; a Paracorr or equivalent coma corrector is not optional but effectively required for any wide-angle eyepiece, adding significant cost on top of the £1099 price.
The open truss design needs a light shroud in anything less than a fully dark site to maintain contrast — without one, even moderate ambient light washes out the faint targets this scope is built to reveal.
Which is right for you?
Two different buyers. Two different right answers.
The maximum-aperture visual reflector
Explore Scientific · Explore Scientific 12" Dobsonian
You're an experienced visual observer who wants serious deep-sky and planetary capability but still values being able to load the scope into a normal car and set up alone. You have access to dark skies, you're comfortable with collimation, and you want the most resolving power you can practically transport on a regular basis without turning every session into a logistics exercise. You're not interested in astrophotography — you want to look through the eyepiece and see spiral arms, resolved globular cores, and Jovian festoons, and you'd rather save £100 and a lot of back strain compared to the next size up.
The maximum-aperture visual reflector
Sky-Watcher · Sky-Watcher Skyliner 350P
You're chasing the faintest targets a production Dobsonian can reach — dim galaxy groups, interacting pairs, Palomar globulars — and you've already decided that maximum aperture-per-pound is your priority over convenience. You have a van or large vehicle, ideally ground-floor storage, and you don't mind recruiting a friend for transport nights. You're experienced enough that critical collimation at f/4.5, thermal management of a 355mm mirror, and constant manual tracking at high power don't intimidate you — they're just part of the routine. If you don't have the vehicle, the storage, or the patience for that level of setup discipline, the 12-inch delivers 80% of the views at half the physical burden.
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 Explore Scientific 12" Dobsonian is the scope most people will be using regularly six months from now. The Sky-Watcher Skyliner 350P rewards you more once you know what you're doing — it's worth revisiting after your first year.
Explore Scientific 12" Dobsonian
View Explore Scientific 12" Dobsonian →Sky-Watcher Skyliner 350P
View Sky-Watcher Skyliner 350P →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 | Explore Scientific 12" Dobsonian | Sky-Watcher Skyliner 350P |
|---|---|---|
Apertureⓘ The most important spec — bigger = more light = better views | 305mm | 355mm |
Focal Length Longer = more magnification potential | 1524mm | 1600mm |
Focal Ratio Lower f-number = wider field of view; higher = more magnification per eyepiece | f/4.99 | f/4.51 |
Optical Design The type of optics — each design has different strengths | Dobsonian | Dobsonian |
Coatings Better coatings = more light transmission through the optics | Parabolic primary mirror, fully coated | Parabolic primary mirror, fully multi-coated |
How do you point it?
| Spec | Explore Scientific 12" Dobsonian | Sky-Watcher Skyliner 350P |
|---|---|---|
Mount Type The mechanical system that holds and moves the telescope | Dobsonian | Dobsonian |
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 | Explore Scientific 12" Dobsonian | Sky-Watcher Skyliner 350P |
|---|---|---|
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) | Dual-speed Crayford (10:1 reduction) |
Size & weight
| Spec | Explore Scientific 12" Dobsonian | Sky-Watcher Skyliner 350P |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 22kg | 36kg |
Total Weightⓘ Full setup including mount — this is what you lug to the car | 34kg | 58kg |
Tube Length | 1500mm | 1600mm |
Tube Material | Steel | Steel |
What's in the box?
| Spec | Explore Scientific 12" Dobsonian | Sky-Watcher Skyliner 350P |
|---|---|---|
Eyepieces Included eyepieces — more is better, but quality matters more than quantity | 25mm eyepiece | 25mm and 10mm Super eyepieces |
Finder Scope Helps you locate areas of the sky before switching to the main eyepiece | 8x50 right-angle finder | 8x50 right-angle correct-image finder |
Diagonal Tilts the eyepiece 90° for comfortable viewing — useful on refractors |
Blue highlight: Explore Scientific 12" Dobsonian advantage · Amber highlight: Sky-Watcher Skyliner 350P advantage · Greyed cells: equal or subjective.