Telescope Comparison
Bresser Messier 8" Dobsonian vs Sky-Watcher Heritage 150P
203mm versus 150mm — the aperture difference is the comparison.
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 · £199
The grab-and-go tabletop reflector
- 150mm Newtonian on a tabletop Dobsonian rocker-box mount
- Good for: Moon, planets, open clusters, bright nebulae
- No alignment procedure — set it on any solid surface and observe immediately
- Needs a stable surface at a comfortable height: garden table, wall, or car tailgate
- Mirrors need occasional collimation — straightforward with a Cheshire eyepiece once learned
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 Heritage 150P's shorter focal length gives a wider true field — better for large open clusters and extended nebulae.
Focal ratio
Sky-Watcher Heritage 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
Same mount type — setup experience and ergonomics will be similar. Differences lie in build quality and included accessories.
Weight (OTA)
Sky-Watcher Heritage 150P's optical tube is 6.3kg 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 Heritage 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 Heritage 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 crater walls, rilles, and shadow detail; the relatively short f/5 ratio benefits from a Barlow for high-power lunar work |
| Saturn | Excellent Cassini Division visible in steady seeing, cloud banding on the disc, and several moons including Titan easily spotted | Good Rings clearly defined, Cassini Division visible in steady seeing; 750mm focal length means you'll need a short eyepiece or Barlow for best scale |
| Jupiter | Excellent Multiple cloud belts, Great Red Spot, and all four Galilean moons with shadow transits visible | Good Two main equatorial belts, Great Red Spot, and Galilean moons; 150mm resolves some secondary belt structure in good conditions |
| Mars | Good Polar cap and dark surface features visible at opposition; the 1200mm focal length allows useful magnification with a short eyepiece | Good At opposition the disc shows polar cap and dark surface markings; limited by the 750mm focal length requiring high-power eyepieces |
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 Bright nebulosity fills the field with sweeping wings of gas; Trapezium stars cleanly split; f/5 speed gives excellent surface brightness |
| 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 | Good Bright core and inner halo visible with hints of dust lane; at 750mm focal length the full 3° extent is cropped in most eyepieces but the core view is detailed |
| Open clusters | Moderate Compact clusters like the Double Cluster look fine, but large sprawling clusters like the Pleiades overfill the field at 1200mm | Excellent 750mm focal length with a wide-field eyepiece frames the Double Cluster, Pleiades, and M35 beautifully; f/5 speed gives bright star images |
| Globular clusters | Excellent 203mm resolves individual stars across the outer regions of M13 and M5; a defining strength of this aperture class | Good M13 and M3 show partial resolution into stars at the edges with a granular core — 150mm is right at the threshold for meaningful resolution |
| 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 pulls in galaxies like M81/M82, M51, and the Leo Triplet as defined smudges with hints of structure under dark skies |
| 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 with a 25mm+ eyepiece gives attractive star-rich sweeps through Cygnus and Sagittarius; wider dedicated instruments do this better |
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 doubles down to about 0.8 arcseconds; the f/5 focal ratio means less clean diffraction patterns than a long-focal-ratio refractor, but Albireo, the Double Double, and Mizar are easy |
| 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 applicable |
| 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 | Moderate Short planetary video captures are possible with a webcam or phone adapter, but manual tracking makes keeping the planet centered difficult at high magnification |
The real tradeoff
Both scopes are capable. The question is which one fits the way you actually observe.
Bresser Messier 8" Dobsonian
- You'll see genuinely more — that extra 53mm of aperture over the Heritage 150P means M13 resolves stars deeper into the core, M51's spiral arms become real structure rather than a hint, and faint galaxies that are barely-there smudges in 150mm become objects worth spending time on.
- You'll commit to the session every time you observe — hauling a 20kg, 1.2m tube outside, letting it cool down, and collimating before you start means this is never a spontaneous ten-minute peek; it's a deliberate hour-plus affair, and you'll love it or resent it depending on your temperament.
- You'll nail planetary focus more easily thanks to the dual-speed Crayford focuser — dialling in the sharpest view of Saturn's Cassini Division at 200× is a noticeably smoother experience than fighting a single-speed rack-and-pinion, and that's a real advantage you'll appreciate on every high-power night.
Sky-Watcher Heritage 150P
- You'll actually use this scope on weeknights — at 5.6kg with a collapsible tube, you can grab it off a shelf, set it on a garden table, and be observing Saturn's rings within five minutes, which means you'll log far more hours under the stars than you would with a scope that demands a production to set up.
- You'll need to solve the table problem before anything else — without a rock-solid surface at the right height, the view shakes with every touch of the focuser, and you'll spend more time cursing the wobble than enjoying Jupiter's cloud belts.
- You'll be surprised how much a 150mm scope shows, but you'll also hit its ceiling sooner — fainter galaxies stay as shapeless glows, globular clusters don't resolve as deeply, and you'll find yourself wanting more aperture once you've learned the sky, which is exactly the problem this scope is designed to give you.
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 total weight rule out balcony use, car boot trips, and anywhere without dedicated storage space — if you live in a flat, this scope may never leave the house.
The Dobsonian base lacks fine altitude control, so heavier eyepieces or accessories can tip the tube; many owners end up adding a tension spring mod to restore smooth tracking near the zenith.
At f/5.9, coma distortion is visible at the edges of wide-angle eyepieces — a coma corrector adds £80–£130 on top of the purchase price to fully exploit a quality 2" wide-field eyepiece.
Sky-Watcher
Sky-Watcher Heritage 150P
The open FlexTube design lets stray light flood in from the side, washing out contrast on faint deep-sky objects — you'll want a fabric light shroud almost immediately, and that's an accessory you'll have to source or make yourself.
The f/5 focal ratio is punishing on cheap eyepieces — the included 10mm Kellner shows noticeable coma and edge blurring, and budget Plössls aren't much better, so you'll need to invest in at least one decent wide-angle eyepiece to see what the optics can really do.
Collimation drifts every time you collapse and extend the tube, so you'll need a collimation cap or laser collimator and the willingness to check alignment at the start of most sessions.
Which is right for you?
Two different buyers. Two different right answers.
The maximum-aperture visual reflector
Bresser · Bresser Messier 8" Dobsonian
You want the most visual performance you can get for under £350, and you're willing to earn it. You have storage space for a 1.2m tube, a garden or dark-sky site you can drive to, and you're the kind of person who sets aside an evening for observing rather than grabbing five minutes between tasks. You want to resolve individual stars in globular clusters, trace spiral arms in galaxies, and push planetary magnification to 200×+ with a focuser that can handle it. If you're a beginner ready to learn collimation, or a family that wants a communal scope for weekend stargazing, the Bresser 8" rewards your patience with views the Heritage 150P simply cannot match.
The grab-and-go tabletop reflector
Sky-Watcher · Sky-Watcher Heritage 150P
You want a real telescope that you'll actually use on a Tuesday night. You have a balcony, a garden table, or a travel bag — not a garage full of astronomy gear — and you value the difference between a scope that gets set up and a scope that stays in the cupboard. You're a beginner who wants to see Saturn's rings, resolve stars in M13, and sweep the Milky Way without committing to a 20kg setup ritual. You understand you're trading about 35% of the Bresser's light-gathering power for a scope you can carry in one hand, and that trade-off makes sense because the best telescope is the one you point at the sky.
Our verdict
At £199 versus £349, the Bresser Messier 8" Dobsonian costs 75% more. It delivers 53mm more aperture — a real and visible advantage on faint targets.
If budget is a genuine constraint, the Sky-Watcher Heritage 150P will make you a happy observer. The Bresser Messier 8" Dobsonian'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 Heritage 150P, use it for a year, then upgrade knowing exactly what you want.
Bresser Messier 8" Dobsonian
View Bresser Messier 8" Dobsonian →Sky-Watcher Heritage 150P
View Sky-Watcher Heritage 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 Heritage 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 with multi-coated optics |
How do you point it?
| Spec | Bresser Messier 8" Dobsonian | Sky-Watcher Heritage 150P |
|---|---|---|
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 8" Dobsonian | Sky-Watcher Heritage 150P |
|---|---|---|
Focuser Size 2" accepts wider eyepieces and gives better low-power views | 2" | 1.25" |
Focuser Type Rack-and-pinion is standard; Crayford and dual-speed are smoother | Dual-speed Crayford (2" with 1.25" adapter) | Rack and pinion |
Size & weight
| Spec | Bresser Messier 8" Dobsonian | Sky-Watcher Heritage 150P |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 11.5kg | 5.2kg |
Total Weightⓘ Full setup including mount — this is what you lug to the car | 17.5kg | 5.2kg |
Tube Length | 1200mm | 550mm |
Tube Material | Steel | Steel (collapsible FlexTube) |
What's in the box?
| Spec | Bresser Messier 8" Dobsonian | Sky-Watcher Heritage 150P |
|---|---|---|
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 | Red dot finder |
Diagonal Tilts the eyepiece 90° for comfortable viewing — useful on refractors |
Blue highlight: Bresser Messier 8" Dobsonian advantage · Amber highlight: Sky-Watcher Heritage 150P advantage · Greyed cells: equal or subjective.