Telescope Comparison
Bresser Messier 8" Dobsonian vs Sky-Watcher Quattro 150P
The Bresser Messier 8" Dobsonian is a complete setup. The Sky-Watcher Quattro 150P needs a mount before it's usable.
First light
Bresser · 203mm · £349
The maximum-aperture visual reflector
- 203mm 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
- 17.5kg total — designed for a fixed garden or regular dark-sky site, not casual transport
Sky-Watcher · 150mm · £399
The custom-rig optical tube
- 150mm newtonian reflector — optical tube only, no mount included
- 750mm focal length at f/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
Bresser Messier 8" Dobsonian gathers 1.8× 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 8" Dobsonian's longer focal length reaches higher magnification with the same eyepiece — better reach for planetary detail. Sky-Watcher Quattro 150P's shorter focal length gives a wider true field — better for large open clusters and extended nebulae.
Focal ratio
Sky-Watcher Quattro 150P's faster f/5 delivers wider fields with any eyepiece — better for open clusters and large nebulae. Bresser Messier 8" Dobsonian's f/5.91 provides more magnification per eyepiece — better for fine planetary detail.
Mount type
Sky-Watcher Quattro 150P has no mount — add a compatible mount before you can observe. Bresser Messier 8" Dobsonian is a complete ready-to-use system.
Weight (OTA)
Sky-Watcher Quattro 150P's optical tube is 6.9kg lighter. Relevant if you plan to use it on multiple mounts or carry the tube to dark-sky sites separately.
Optical design
Bresser Messier 8" Dobsonian is a DOBSONIAN; Sky-Watcher Quattro 150P 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 8" Dobsonian | Sky-Watcher Quattro 150P |
|---|---|---|
| Planets | ||
| Moon | Excellent 203mm aperture resolves craters down to a few kilometres; the dual-speed focuser helps nail sharp focus at high power | Excellent 150mm aperture delivers crisp lunar detail; the f/5 focal ratio is less forgiving at high magnification but still rewards visual observation |
| Saturn | Excellent Cassini Division visible in steady seeing, cloud banding on the disc, and several moons including Titan easily spotted | Good 150mm resolves rings and Cassini Division; 750mm focal length falls short of the 1000mm+ ideal for high-magnification planetary detail |
| Jupiter | Excellent Multiple cloud belts, Great Red Spot, and all four Galilean moons with shadow transits visible | Good Cloud belts, GRS, and Galilean moons visible; faster focal ratio demands quality eyepieces for clean high-power views |
| Mars | Good Polar cap and dark surface features visible at opposition; the 1200mm focal length allows useful magnification with a short eyepiece | Good 150mm aperture shows polar caps and major albedo features near opposition; limited focal length constrains useful magnification |
Deep sky | ||
| Orion Nebula (M42) | Excellent Bright layered nebulosity with Trapezium resolved; 1200mm focal length crops the widest extent but detail in the core is superb | Excellent 150mm aperture and wide f/5 field frame the full nebula with surrounding running man region — superb both visually and for imaging |
| Andromeda Galaxy (M31) | Moderate 1200mm focal length shows the bright core and inner disc well, but the full 3° extent of the galaxy is cropped even with a wide-field 2" eyepiece | Excellent 750mm focal length captures the full extent of M31 on an APS-C sensor; visually the core and dust lanes are evident |
| Open clusters | Moderate Compact clusters like the Double Cluster look fine, but large sprawling clusters like the Pleiades overfill the field at 1200mm | Excellent Wide field at 750mm frames large clusters like the Double Cluster and Pleiades beautifully |
| Globular clusters | Excellent 203mm resolves individual stars across the outer regions of M13 and M5; a defining strength of this aperture class | Good 150mm begins to resolve outer stars in M13 and M22; core remains granular rather than fully resolved |
| Faint galaxies | Good Galaxy groups like the Leo Triplet and Virgo Cluster members are within reach; spiral arm hints visible in M51 under dark skies | Good 150mm gathers enough light for many NGC galaxies; imaging with stacked exposures reveals detail well beyond what's visible at the eyepiece |
| Milky Way / wide field | Not recommended 1200mm focal length is far too narrow for sweeping star fields — a wide-field refractor or binoculars serve this purpose better | Good 750mm focal length gives rich star fields but is narrower than the sub-400mm ideal for true Milky Way sweeps |
Other | ||
| Double stars | Excellent 203mm aperture resolves doubles down to about 0.6 arcseconds; Dawes limit easily splits Albireo, the Double Double in Lyra, and many tighter pairs | Good 150mm resolves sub-arcsecond pairs in theory, but the f/5 focal ratio is less forgiving than long focal ratio refractors for clean splitting |
| Astrophotography (deep sky) | Not recommended No tracking means exposures beyond a second or two trail; manual Dobsonian mount is unsuitable for deep-sky imaging | Not recommended No mount or tracking included — the OTA is designed for deep-sky imaging but requires a separately purchased equatorial mount to function as an astrograph |
| Astrophotography (planetary) | Moderate Planetary video capture with a high-speed camera is feasible — 203mm aperture and 1200mm focal length give a usable image scale, but manual tracking makes it fiddly | Good 150mm provides decent planetary image scale; a 2× Barlow brings effective focal length to 1500mm which helps, but no mount is included |
| Emission nebulae (wide-field imaging) | Not applicable | Excellent The f/5 speed and 750mm focal length are ideal for large emission targets like the Rosette, Veil, and North America Nebulae when paired with a suitable mount and narrowband filters |
The real tradeoff
Both scopes are capable. The question is which one fits the way you actually observe.
Bresser Messier 8" Dobsonian
- You'll carry the tube outside, drop it on the base, and be staring at M13's resolved stars within fifteen minutes — no laptop, no power supply, no cables, just you nudging a big light bucket across the sky.
- You'll spend your sessions chasing the next faint fuzzy with your own eyes — spiral arms in M51, the Trapezium in Orion, Saturn's Cassini Division — and the dual-speed Crayford focuser means you'll nail critical focus at 200× without the usual overshoot-and-swear routine.
- You'll also spend thirty seconds every minute or two giving the scope a gentle nudge to keep Jupiter centred, and you'll learn to collimate before every session or accept mushy stars as your punishment for skipping it.
Sky-Watcher Quattro 150P
- You'll unbox a bare tube with no mount, no eyepiece, no finder, and no coma corrector — your first observing session is still hundreds of pounds and several purchases away, because this is an imaging component, not a telescope kit.
- You'll spend your evenings polar-aligning an equatorial mount, framing targets on a laptop screen, and stacking sub-exposures — but the reward is capturing the full sweep of the Veil Nebula or the faint outer arms of M31 in a single APS-C frame at a fast f/5.
- You'll learn collimation matters even more here than on a slower scope, and you'll discover that every imaging session is an exercise in patience: guiding calibration, focus runs, and troubleshooting tilt before a single usable frame hits your drive.
The dark side
Every scope has a personality. Here’s where each one gets difficult.
Bresser
Bresser Messier 8" Dobsonian
The 1.2m tube and ~20kg assembled weight mean you're committing to a dedicated setup — this won't fit on a balcony and it won't ride in a hatchback alongside passengers.
No tracking of any kind: at high magnification objects drift out of view in under a minute, so planetary observing becomes a rhythmic cycle of nudge, look, nudge, look.
The Dobsonian base lacks fine altitude control out of the box — heavier eyepieces or a camera will tip the tube, and you'll likely need a spring-tension mod to restore balance.
Sky-Watcher
Sky-Watcher Quattro 150P
The OTA-only package means you need to budget separately for a capable equatorial mount (£500+), a coma corrector (£100–200), a guide scope and camera, and basic accessories — the total imaging system cost dwarfs the £399 tube price.
At f/5, coma distortion at the field edges is severe enough that a coma corrector is mandatory for imaging, not a nice-to-have — without one, stars at the corners will look like seagulls.
The short 750mm focal length gives poor planetary image scale — if you want to shoot Jupiter or Saturn, you'll need a Barlow or a completely different scope, because this focal length simply can't deliver the magnification.
Which is right for you?
Two different buyers. Two different right answers.
The maximum-aperture visual reflector
Bresser · Bresser Messier 8" Dobsonian
You want to see the night sky with your own eyes, tonight, without a computer in the loop. You're a beginner or a family looking for the most rewarding visual views you can get for under £400, and you're happy to collimate, nudge, and learn the sky by hand. You have room to store a 1.2m tube and the patience to let it cool down before observing. If you've never seen a globular cluster resolve into stars or watched Saturn's rings snap into focus, this is the scope that delivers those moments with the least fuss and the most aperture per pound.
The custom-rig optical tube
Sky-Watcher · Sky-Watcher Quattro 150P
You've already decided you want to photograph deep-sky objects, you understand what polar alignment and autoguiding mean, and you're shopping for an affordable fast Newtonian astrograph to sit on a mount you already own or plan to buy. You're comfortable spending two to three times the OTA price on the supporting gear, and you're excited about framing large nebulae at f/5 rather than squinting through an eyepiece. If you haven't imaged before or you just want to look through a telescope, this is categorically the wrong purchase — get the Bresser instead and start learning the sky visually.
Our verdict
This comparison has a catch: the Sky-Watcher Quattro 150P is a bare optical tube. You cannot use it without a separate mount — which adds meaningful cost and complexity. The Bresser Messier 8" Dobsonian is a complete, ready-to-observe package.
For most buyers, the Bresser Messier 8" Dobsonian is the right choice — you can observe the same night it arrives. The Sky-Watcher Quattro 150P 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 8" Dobsonian, without hesitation.
Bresser Messier 8" Dobsonian
View Bresser Messier 8" Dobsonian →Sky-Watcher Quattro 150P
View Sky-Watcher Quattro 150P →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 8" Dobsonian | Sky-Watcher Quattro 150P |
|---|---|---|
Apertureⓘ The most important spec — bigger = more light = better views | 203mm | 150mm |
Focal Length Longer = more magnification potential | 1200mm | 750mm |
Focal Ratio Lower f-number = wider field of view; higher = more magnification per eyepiece | f/5.91 | f/5 |
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 8" Dobsonian | Sky-Watcher Quattro 150P |
|---|---|---|
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 8" Dobsonian | Sky-Watcher Quattro 150P |
|---|---|---|
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 8" Dobsonian | Sky-Watcher Quattro 150P |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 11.5kg | 4.6kg |
Total Weight Full setup including mount — this is what you lug to the car | 17.5kg | — |
Tube Length | 1200mm | — |
Tube Material | Steel | Steel |
What's in the box?
| Spec | Bresser Messier 8" Dobsonian | Sky-Watcher Quattro 150P |
|---|---|---|
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 8" Dobsonian advantage · Amber highlight: Sky-Watcher Quattro 150P advantage · Greyed cells: equal or subjective.