Telescope Comparison
Bresser Messier 12" Dobsonian vs Sky-Watcher Quattro 250P
The Bresser Messier 12" Dobsonian is a complete setup. The Sky-Watcher Quattro 250P needs a mount before it's usable.
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 · 254mm · £999
The custom-rig optical tube
- 254mm newtonian reflector — optical tube only, no mount included
- 1000mm focal length at f/3.94
- 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
Bresser Messier 12" Dobsonian 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
Bresser Messier 12" Dobsonian's longer focal length reaches higher magnification with the same eyepiece — better reach for planetary detail. Sky-Watcher Quattro 250P's shorter focal length gives a wider true field — better for large open clusters and extended nebulae.
Focal ratio
Sky-Watcher Quattro 250P's faster f/3.94 delivers wider fields with any eyepiece — better for open clusters and large nebulae. Bresser Messier 12" Dobsonian's f/5 provides more magnification per eyepiece — better for fine planetary detail.
Mount type
Sky-Watcher Quattro 250P has no mount — add a compatible mount before you can observe. Bresser Messier 12" Dobsonian is a complete ready-to-use system.
Weight (OTA)
Sky-Watcher Quattro 250P's optical tube is 13.5kg lighter. Relevant if you plan to use it on multiple mounts or carry the tube to dark-sky sites separately.
Optical design
Bresser Messier 12" Dobsonian is a DOBSONIAN; Sky-Watcher Quattro 250P is a Newtonian reflector (mirrors, needs occasional collimation). Different optical formulas produce different strengths — reflectors give more aperture per pound; refractors give sharper contrast and require no collimation.
At the eyepiece
| Target | Bresser Messier 12" Dobsonian | Sky-Watcher Quattro 250P |
|---|---|---|
| Planets | ||
| Moon | Excellent 305mm aperture delivers overwhelming detail — craterlets, rilles, and shadow play at 200–300×; a neutral density filter helps manage brightness | Excellent 254mm aperture delivers superb lunar detail, though the fast f/3.9 ratio limits useful magnification compared to longer focal length scopes |
| Saturn | Excellent Cassini Division easily visible, Crepe Ring and cloud banding on the disc accessible in steady seeing at 250×+ | Good 254mm resolves rings, Cassini Division, and cloud banding, but 1000mm focal length at f/3.9 makes high-power planetary observation less comfortable than a longer focal ratio instrument |
| Jupiter | Excellent Multiple cloud belts, festoons, the Great Red Spot, and moon shadow transits visible; 1525mm focal length supports high magnification well | Good Aperture easily resolves cloud belts and the Great Red Spot, but the fast focal ratio and imaging-oriented design are not ideal for sustained high-magnification visual planetary work |
| Mars | Excellent At 305mm and 1525mm focal length, dark albedo features, polar caps, and occasional dust storm effects visible near opposition | Good 254mm aperture shows polar caps and dark surface features at opposition; limited by 1000mm focal length for high-magnification detail |
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 254mm of aperture and f/3.9 speed make this a superb imaging target; visually the nebulosity is stunning with extended structure visible |
| 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 | Good 1000mm focal length captures the bright core and inner disc but crops the full 3° extent; excellent for imaging the core and dust lanes |
| Open clusters | Moderate 1525mm focal length means larger clusters like the Double Cluster overfill the field; compact clusters like M37 are well-served | Good 1000mm focal length frames smaller open clusters like M35 and M37 well; larger clusters like the Double Cluster may overfill the field |
| Globular clusters | Excellent 305mm resolves individual stars across the core of M13, M3, and M5 — one of this scope's signature strengths | Excellent 254mm aperture resolves individual stars across globulars like M13 and M3; imaging at f/3.9 captures them quickly |
| 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 254mm aperture and fast focal ratio are ideal for pulling faint galaxy detail — spiral arms, tidal streams — in short integration times |
| 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 1000mm focal length is far too narrow for sweeping Milky Way fields; this is a medium-field deep-sky instrument |
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 254mm aperture has a Dawes limit around 0.45 arcseconds, resolving tight doubles; however the fast focal ratio makes clean splitting less comfortable than a long-FL refractor |
| Astrophotography (deep sky) | Not recommended Manual Dobsonian mount has no tracking — long exposures are not possible | Not recommended OTA only — no mount or tracking included; on a suitable equatorial mount (EQ6-R or better) this would rate Excellent, but the scope as sold cannot track |
| 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 | Not recommended No mount or tracking included; with a tracking mount the 254mm aperture and 1000mm focal length (extendable with a Barlow) would rate Good to Excellent |
| Emission nebulae (imaging) | Not applicable | Excellent The f/3.9 speed is purpose-built for faint emission targets — Veil, North America, Heart and Soul — requiring a fraction of the exposure time of slower scopes |
| Galaxy groups (imaging) | Not applicable | Excellent 1000mm focal length and large aperture frame galaxy groups like the Leo Triplet and Markarian's Chain with strong detail on spiral arms and faint extensions |
The real tradeoff
Both scopes are capable. The question is which one fits the way you actually observe.
Bresser Messier 12" Dobsonian
- You'll spend the first half hour waiting for the 12-inch mirror to cool down, then the next three hours watching globular clusters resolve into individual stars and galaxies reveal structure that no screen can replicate — this scope rewards patience and dark skies with real-time views that feel earned.
- You'll be wrestling 42kg of telescope into and out of your car every session, and you'll be nudging the tube by hand to track Jupiter at 300×, losing it every time you blink — but you'll also see festoons in Jupiter's cloud belts and the Crepe Ring on Saturn without a single piece of electronics.
- You'll quickly learn that the included eyepieces are holding back what this mirror can do, and you'll budget for a 2-inch wide-angle eyepiece and a coma corrector within weeks of first light — but even with the stock kit, M13 resolved to the core will stop you in your tracks.
Sky-Watcher Quattro 250P
- You'll unbox a tube and realise you're only a third of the way to a working imaging rig — the mount alone will cost twice what the OTA did, and you still need a coma corrector, guide scope, guide camera, and motorised focuser before you capture a single usable frame.
- You'll spend your first few sessions fighting collimation and backfocus tolerances measured in microns, not millimetres — but once dialled in, the f/3.9 focal ratio lets you pull faint spiral arms out of galaxies in sub-exposure times that would be impossible at f/8.
- You'll process your images the next morning at a desk, stacking hundreds of frames to reveal the Veil Nebula's filaments or IC 1396's dust lanes — the reward comes hours after the session, not during it, and it lives on a hard drive rather than in a memory.
The dark side
Every scope has a personality. Here’s where each one gets difficult.
Bresser
Bresser Messier 12" Dobsonian
At 42kg total weight, solo setup is genuinely physical — you need a car with enough boot space and enough strength to lift the base and tube separately, every single session.
The f/5 focal ratio produces noticeable coma in the outer 30% of wide-angle eyepiece fields, so a coma corrector isn't optional if you care about edge sharpness — add that to the real cost.
No tracking of any kind means planets drift out of the field of view in seconds at high power, and deep-sky objects at 250× require constant manual nudging — extended planetary observation becomes an exercise in frustration.
Sky-Watcher
Sky-Watcher Quattro 250P
The OTA ships with no mount, and the minimum viable mount is an EQ6-R class costing £1,500–£3,000+, making the true entry cost of this imaging system potentially four to five times the advertised tube price.
At f/3.9 the depth of focus is approximately 50 microns, meaning even slight temperature shifts or focuser sag throw your stars out of focus — a motorised focuser isn't a luxury, it's a requirement, and the stock dual-speed Crayford has been reported to sag under heavy camera loads.
Coma at f/3.9 is severe enough that stars are visibly distorted across most of the field without a matched coma corrector — this telescope is essentially unusable for its intended purpose without one.
Which is right for you?
Two different buyers. Two different right answers.
The maximum-aperture visual reflector
Bresser · Bresser Messier 12" Dobsonian
You want to look through an eyepiece and see things with your own eyes — resolved stars in globular clusters, structure in galaxies, filaments in nebulae — and you're willing to haul 42kg to a dark site to do it. You're an intermediate observer who's outgrown an 8-inch scope and wants the most aperture you can get for under £700, and you don't care about astrophotography. If you have a bad back, a small car, or limited storage, this isn't your scope.
The custom-rig optical tube
Sky-Watcher · Sky-Watcher Quattro 250P
You're an experienced astrophotographer who already owns or is ready to invest in a heavy-duty equatorial mount, and you want the fastest possible Newtonian astrograph to cut your integration times on faint nebulae and galaxies. You understand collimation, backfocus, and guiding, and you have the budget for the full imaging chain — corrector, guide setup, motorised focuser — on top of the tube price. If you want to look through an eyepiece, or if this is your first telescope, the Quattro 250P will punish you.
Our verdict
This comparison has a catch: the Sky-Watcher Quattro 250P is a bare optical tube. You cannot use it without a separate mount — which adds meaningful cost and complexity. The Bresser Messier 12" Dobsonian is a complete, ready-to-observe package.
For most buyers, the Bresser Messier 12" Dobsonian is the right choice — you can observe the same night it arrives. The Sky-Watcher Quattro 250P makes sense if you already own a compatible mount, or are deliberately building a specific imaging setup piece by piece. If I had to choose for a first telescope: the Bresser Messier 12" Dobsonian, without hesitation.
Bresser Messier 12" Dobsonian
View Bresser Messier 12" Dobsonian →Sky-Watcher Quattro 250P
View Sky-Watcher Quattro 250P →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 Quattro 250P |
|---|---|---|
Apertureⓘ The most important spec — bigger = more light = better views | 305mm | 254mm |
Focal Length Longer = more magnification potential | 1525mm | 1000mm |
Focal Ratio Lower f-number = wider field of view; higher = more magnification per eyepiece | f/5 | f/3.94 |
Optical Design The type of optics — each design has different strengths | Dobsonian | Newtonian Reflector |
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 Quattro 250P |
|---|---|---|
Mount Type The mechanical system that holds and moves the telescope | Dobsonian | 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 | Bresser Messier 12" Dobsonian | Sky-Watcher Quattro 250P |
|---|---|---|
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 Quattro 250P |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 27kg | 13.5kg |
Total Weight Full setup including mount — this is what you lug to the car | 42kg | — |
Tube Length | 1525mm | — |
Tube Material | Steel | Steel |
What's in the box?
| Spec | Bresser Messier 12" Dobsonian | Sky-Watcher Quattro 250P |
|---|---|---|
Eyepieces Included eyepieces — more is better, but quality matters more than quantity | 25mm and 10mm eyepieces | — |
Finder Scope Helps you locate areas of the sky before switching to the main eyepiece | 8x50 right-angle finder | — |
Diagonal Tilts the eyepiece 90° for comfortable viewing — useful on refractors |
Blue highlight: Bresser Messier 12" Dobsonian advantage · Amber highlight: Sky-Watcher Quattro 250P advantage · Greyed cells: equal or subjective.