Telescope Comparison
Bresser Messier 12" Dobsonian vs Sky-Watcher Skyliner 300P
The specs are close. The experience isn't.
First light
Bresser · 305mm · £699
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
- 42kg total — designed for a fixed garden or regular dark-sky site, not casual transport
Sky-Watcher · 304mm · £659
The maximum-aperture visual reflector
- 304mm 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
- 38kg 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
Bresser Messier 12" Dobsonian gathers 1× 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
Bresser Messier 12" Dobsonian's longer focal length reaches higher magnification with the same eyepiece — better reach for planetary detail. Sky-Watcher Skyliner 300P'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
Same mount type — setup experience and ergonomics will be similar. Differences lie in build quality and included accessories.
Weight (OTA)
Sky-Watcher Skyliner 300P's optical tube is 3.0kg 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 | Bresser Messier 12" Dobsonian | Sky-Watcher Skyliner 300P |
|---|---|---|
| Planets | ||
| Moon | Excellent 305mm aperture delivers overwhelming detail — craterlets, rilles, and shadow play at 200–300×; a neutral density filter helps manage brightness | Excellent 304mm aperture delivers overwhelming lunar detail — tiny craterlets, rilles, and mountain shadows at 250x+ |
| Saturn | Excellent Cassini Division easily visible, Crepe Ring and cloud banding on the disc accessible in steady seeing at 250×+ | Excellent Cassini Division clear, cloud banding on the disc, and multiple moons visible at 200–300x |
| Jupiter | Excellent Multiple cloud belts, festoons, the Great Red Spot, and moon shadow transits visible; 1525mm focal length supports high magnification well | Excellent Multiple belt structures, festoons, GRS, and moon shadow transits visible in good seeing |
| Mars | Excellent At 305mm and 1525mm focal length, dark albedo features, polar caps, and occasional dust storm effects visible near opposition | Excellent 304mm aperture and 1500mm focal length resolve dark surface features and polar caps at opposition |
Deep sky | ||
| Orion Nebula (M42) | Excellent Trapezium cleanly split, extensive nebulosity with hints of colour; 1525mm focal length crops the widest extent but detail is superb | Excellent Layered nebulosity with structure and possible colour; Trapezium stars pinpoint-sharp |
| Andromeda Galaxy (M31) | Moderate 1525mm focal length shows only the bright core and inner disc — too narrow to frame the full 3° extent; dust lanes visible but outer halo is cropped | Moderate 1500mm focal length crops the outer halo — you see the bright core and dust lanes, but the full 3° extent is lost |
| Open clusters | Moderate 1525mm focal length means larger clusters like the Double Cluster overfill the field; compact clusters like M37 are well-served | Moderate 1500mm focal length means many large clusters (Pleiades, Double Cluster) overfill the field; compact clusters fare better |
| Globular clusters | Excellent 305mm resolves individual stars across the core of M13, M3, and M5 — one of this scope's signature strengths | Excellent 304mm resolves individual stars across the face of M13, M3, M5 and others — a showpiece target for this scope |
| Faint galaxies | Excellent 305mm pulls in galaxies to mag 14+; spiral arm structure visible in M51, NGC 891's dust lane detectable from dark sites | Excellent Spiral arms in M51, dust lane in M82, Leo Triplet resolved — this is where 12 inches of aperture justifies itself |
| Milky Way / wide field | Not recommended 1525mm focal length gives far too narrow a field for sweeping star fields — a separate wide-field instrument is needed | Not recommended 1500mm focal length gives far too narrow a field for sweeping Milky Way star fields |
Other | ||
| Double stars | Excellent 305mm resolves pairs under 0.5 arcsecond; f/5 is faster than ideal for tight doubles but a Barlow sharpens the Airy disc at high power | Excellent 304mm aperture resolves sub-arcsecond pairs; the f/4.9 ratio is less forgiving of seeing than a long-focus refractor, but raw resolving power is high |
| Astrophotography (deep sky) | Not recommended Manual Dobsonian mount has no tracking — long exposures are not possible | Not recommended Manual Dobsonian mount with no tracking — long-exposure imaging is not viable |
| Astrophotography (planetary) | Moderate Lucky imaging with a high-speed camera is technically possible at 305mm, but manual tracking makes it difficult to keep targets centred; results are inconsistent | Challenging Planetary video capture is theoretically possible with short exposures, but manual tracking at 1500mm makes it very difficult in practice |
The real tradeoff
Both scopes are capable. The question is which one fits the way you actually observe.
Bresser Messier 12" Dobsonian
- You're getting an almost identical visual experience to the Skyliner 300P — the 1mm aperture difference is meaningless at the eyepiece, and both scopes will resolve globular cluster cores and show galaxy structure the same way.
- You'll pay about £40 more and carry roughly 4kg extra weight, which you'll feel on the second trip from the car — that's the most tangible difference between these two scopes in daily ownership.
- You're buying into Bresser's ecosystem for accessories, replacement parts, and future upgrades, which is smaller in the UK than Sky-Watcher's — finding compatible focuser upgrades or replacement mirrors may take more searching.
Sky-Watcher Skyliner 300P
- You're getting the same deep-sky performance as the Bresser for £40 less — both scopes sit at the same aperture class and fast focal ratio, so the views of M51's spiral arms or M13's resolved core will be indistinguishable between them.
- You'll appreciate the slightly lighter package at ~38kg versus ~42kg — still a two-trip setup, but you'll notice those 4kg when lifting the mirror box out of the boot at 11pm in a muddy field.
- You're buying into the most widely supported Dobsonian brand in the UK, which means secondhand eyepieces, shrouds, fan mods, and community knowledge are all easier to find when you inevitably start upgrading.
The dark side
Every scope has a personality. Here’s where each one gets difficult.
Bresser
Bresser Messier 12" Dobsonian
At approximately 42kg total, this is the heavier of the two by a meaningful margin — you'll need a large car boot and the willingness to make multiple trips, and solo setup demands real physical effort.
The f/5 focal ratio produces noticeable coma in the outer 30% of the field with wide-angle eyepieces, and the included eyepieces are basic — budget at least another £100–150 for a coma corrector and a decent wide-field eyepiece to get what you paid for.
No tracking or GoTo means every object is found by hand and followed by nudging — at 250–300× on Jupiter, you'll be pushing the scope every 20–30 seconds, which gets old fast on a cold night.
Sky-Watcher
Sky-Watcher Skyliner 300P
The 1.5-metre tube is the dimension that catches people out — measure your car boot before you buy, because this will not fit in many hatchbacks regardless of how you angle it.
The open tube design is more susceptible to stray light than a closed or shrouded design — you'll want to buy or make a light shroud to preserve contrast, especially if you observe near any light pollution.
At f/4.9, coma is marginally more aggressive than the Bresser's f/5 — the difference is subtle, but a coma corrector is even more essential here if you plan to use eyepieces wider than about 60° apparent field.
Which is right for you?
Two different buyers. Two different right answers.
The maximum-aperture visual reflector
Bresser · Bresser Messier 12" Dobsonian
You'll choose the Bresser if you already have a relationship with the brand, prefer its focuser or build quality after handling both in person, or simply can't find the Skyliner in stock. Optically, you're not gaining anything the Sky-Watcher doesn't also deliver — this is a brand preference and availability decision, not a performance one. You should be comfortable with the extra 4kg and the slightly higher price.
The maximum-aperture visual reflector
Sky-Watcher · Sky-Watcher Skyliner 300P
You'll choose the Skyliner 300P if you want the best-supported 12-inch Dobsonian in the UK market — Sky-Watcher's dominance means more online guides, more compatible aftermarket parts, and a stronger resale market when you eventually upgrade. You're saving £40 and a few kilograms, which doesn't sound like much until you've carried a rocker box across a dark field at midnight. If both scopes are available and you have no existing brand loyalty, this is the more practical buy.
Our verdict
Same aperture, same light-gathering, £40 price difference. The extra cost of the Bresser Messier 12" Dobsonian buys a different mount — not better optics.
For most beginners, the Sky-Watcher Skyliner 300P is the right starting point — the optics are identical and the savings are better spent on a quality eyepiece or a dark-sky trip. The Bresser Messier 12" Dobsonian makes sense if the mount it comes with is specifically what you want to learn. If I had to choose: the Sky-Watcher Skyliner 300P — same sky, less money.
Bresser Messier 12" Dobsonian
View Bresser Messier 12" Dobsonian →Sky-Watcher Skyliner 300P
View Sky-Watcher Skyliner 300P →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 | Bresser Messier 12" Dobsonian | Sky-Watcher Skyliner 300P |
|---|---|---|
Apertureⓘ The most important spec — bigger = more light = better views | 305mm | 304mm |
Focal Length Longer = more magnification potential | 1525mm | 1500mm |
Focal Ratio Lower f-number = wider field of view; higher = more magnification per eyepiece | f/5 | f/4.93 |
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 | Bresser Messier 12" Dobsonian | Sky-Watcher Skyliner 300P |
|---|---|---|
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 | Bresser Messier 12" Dobsonian | Sky-Watcher Skyliner 300P |
|---|---|---|
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 (2" with 1.25" adapter) | Dual-speed Crayford (10:1 reduction) |
Size & weight
| Spec | Bresser Messier 12" Dobsonian | Sky-Watcher Skyliner 300P |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 27kg | 24kg |
Total Weightⓘ Full setup including mount — this is what you lug to the car | 42kg | 38kg |
Tube Length | 1525mm | 1500mm |
Tube Material | Steel | Steel |
What's in the box?
| Spec | Bresser Messier 12" Dobsonian | Sky-Watcher Skyliner 300P |
|---|---|---|
Eyepieces Included eyepieces — more is better, but quality matters more than quantity | 25mm and 10mm eyepieces | 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: Bresser Messier 12" Dobsonian advantage · Amber highlight: Sky-Watcher Skyliner 300P advantage · Greyed cells: equal or subjective.