Telescope Comparison
Bresser Messier 8" Dobsonian vs Bresser Messier N-150/750
203mm versus 150mm — the aperture difference is the comparison.
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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
Bresser · 150mm · £229
The sky-learner's equatorial scope
- 150mm newtonian reflector on a manual equatorial mount
- Good for: Moon, planets, bright star clusters and nebulae
- Setup includes rough polar alignment before observing — more steps than a simple alt-az
- Mount axes feel counterintuitive at first; users find they become natural after several sessions
- Keeps the door open for adding tracking motors and moving into astrophotography later
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. Bresser Messier N-150/750's shorter focal length gives a wider true field — better for large open clusters and extended nebulae.
Focal ratio
Bresser Messier N-150/750'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
Bresser Messier 8" Dobsonian's Dobsonian is immediately intuitive — no alignment, push to aim, observe. Bresser Messier N-150/750's equatorial mount requires polar alignment before each session but tracks the sky as Earth rotates, keeping objects centred.
Weight (OTA)
Bresser Messier N-150/750's optical tube is 6.5kg lighter. Relevant if you plan to use it on multiple mounts or carry the tube to dark-sky sites separately.
Optical design
Bresser Messier 8" Dobsonian is a DOBSONIAN; Bresser Messier N-150/750 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
Bresser
Bresser Messier 8" Dobsonian
The Moon fills the field at low power with more detail than you'll have time to explore on any given night. Saturn's rings are unmistakable from the first session; in good seeing, the Cassini Division — the dark gap between the A and B rings — is a genuine target at higher magnification. Jupiter shows two equatorial cloud bands clearly, the four Galilean moons changing position night to night. The Orion Nebula (M42) shows wide nebulosity with the Trapezium splitting cleanly into four points at 80×. The Hercules Cluster (M13) begins to resolve into individual stars at the outer edges at higher magnification. The Andromeda Galaxy (M31) fills a wide-field eyepiece; the bright core and inner disc are obvious, and on a dark night the dust lane becomes visible with careful looking. The Bresser Messier 8" Dobsonian gathers 1.8× more light than the Bresser Messier N-150/750 — a difference that's marginal on bright targets but visible on fainter ones: dimmer galaxies, faint globular clusters, and extended nebulosity that sits below the threshold of the smaller aperture.
Bresser
Bresser Messier N-150/750
The Moon fills the field at low power with more detail than you'll have time to explore on any given night. Saturn's rings are unmistakable from the first session; in good seeing, the Cassini Division — the dark gap between the A and B rings — is a genuine target at higher magnification. Jupiter shows two equatorial cloud bands clearly, the four Galilean moons changing position night to night. The Orion Nebula (M42) shows clear structure — nebulosity spreading around the Trapezium, which splits at moderate power. The Andromeda Galaxy (M31) shows a concentrated core clearly. The Hercules Cluster (M13) shows some resolution at the edges at higher 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 set this on the ground, point it at M13, and see individual stars sprinkled across the cluster's edges — the 53mm of extra aperture over the 150mm genuinely separates 'resolved' from 'granular smudge,' and that difference is what keeps you outside longer.
- Your typical session is beautifully simple: no polar alignment, no counterweights, just plonk the base down and push the tube — but you'll be nudging it every 30–60 seconds at 200× on Saturn, and that constant tapping becomes the background rhythm of your observing life.
- You'll need to budget around the scope: the 1.2m tube means you're committing a wardrobe's worth of storage space and dedicating a car boot to transport, and you'll want to replace the kit eyepieces quickly — but the dual-speed Crayford focuser means at least your focus control is sorted from day one.
Bresser Messier N-150/750
- You'll spend the first five minutes of every session polar-aligning the EQ mount — an annoying ritual the Dob owner never deals with — but once you're aligned, tracking an object by turning one slow-motion knob instead of nudging a heavy tube in two axes feels far more civilised at 150×.
- You'll see the same deep-sky targets as the 8-inch, but noticeably dimmer and with less resolved detail: M13 goes from 'stars popping out' to 'hints of granularity,' and M51's spiral arms that the Dob reveals become a soft glow you'll need averted vision to suspect.
- You're paying £120 less and getting an equatorial mount that at least opens the door to short-exposure planetary imaging with a webcam — something the Dob's alt-az base simply cannot do — though you'll need to add a motor drive before anything beyond a quick lunar snap is realistic.
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 make this a two-trip-to-the-car scope — if you live in a flat or observe from a balcony, it's effectively unusable.
The Dobsonian base has no fine altitude control out of the box, so adding a heavy 2-inch eyepiece can tip the tube and require a DIY tension-spring modification to rebalance.
At f/5.9 coma distorts the outer field with wide-angle eyepieces, and collimation shifts with transport — you'll need to learn to collimate and budget for a coma corrector if edge-of-field stars bother you.
Bresser
Bresser Messier N-150/750
The included EQ mount has no motor drive, so at high magnification objects still drift out of view and any astrophotography beyond a grabbed lunar frame requires an aftermarket motor upgrade.
The mount is rated for visual use but flexes and vibrates under the weight of a camera, so even with a motor added, long-exposure deep-sky imaging on this mount is not realistic.
The f/5 focal ratio is less forgiving of collimation errors than slower scopes and produces noticeable coma at field edges — good wide-angle eyepieces and periodic collimation aren't optional, they're mandatory.
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 best visual views you can get for under £350 and you're willing to dedicate real storage space and car-boot room to get them. You're a beginner or a family who values simplicity — no alignment, no power supply, just push and look — and you're drawn to deep-sky objects like globular clusters and galaxies where every millimetre of aperture matters. You're not interested in astrophotography, and you accept that a 20kg scope with a metre-long tube is something you plan an evening around, not something you grab on impulse.
The sky-learner's equatorial scope
Bresser · Bresser Messier N-150/750
You want a versatile first scope that costs less, takes up less room, and leaves the door open for experimenting with planetary webcam imaging down the line. You're willing to learn polar alignment and deal with an equatorial mount's learning curve because you like the idea of single-axis tracking and the mechanical foundation for future upgrades. You accept that 150mm will show you less detail than 200mm on every single target — dimmer galaxies, less resolution on globulars, fewer planetary belts — and you're okay with that trade because portability, price, and future flexibility matter more to you right now.
Our verdict
At £229 versus £349, the Bresser Messier 8" Dobsonian costs 52% more. It delivers 53mm more aperture — a real and visible advantage on faint targets.
If budget is a genuine constraint, the Bresser Messier N-150/750 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 Bresser Messier N-150/750, use it for a year, then upgrade knowing exactly what you want.
Bresser Messier 8" Dobsonian
View Bresser Messier 8" Dobsonian →Bresser Messier N-150/750
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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 | Bresser Messier N-150/750 |
|---|---|---|
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 coated |
How do you point it?
| Spec | Bresser Messier 8" Dobsonian | Bresser Messier N-150/750 |
|---|---|---|
Mount Type The mechanical system that holds and moves the telescope | Dobsonian | Equatorial |
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 | Bresser Messier N-150/750 |
|---|---|---|
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 (2" with 1.25" adapter) |
Size & weight
| Spec | Bresser Messier 8" Dobsonian | Bresser Messier N-150/750 |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 11.5kg | 5kg |
Total Weightⓘ Full setup including mount — this is what you lug to the car | 17.5kg | 13.5kg |
Tube Length | 1200mm | 670mm |
Tube Material | Steel | Steel |
What's in the box?
| Spec | Bresser Messier 8" Dobsonian | Bresser Messier N-150/750 |
|---|---|---|
Eyepieces Included eyepieces — more is better, but quality matters more than quantity | 25mm and 10mm eyepieces | 25mm and 10mm eyepieces |
Finder Scope Helps you locate areas of the sky before switching to the main eyepiece | 8x50 right-angle finder | 8x50 optical finder |
Diagonal Tilts the eyepiece 90° for comfortable viewing — useful on refractors |
Blue highlight: Bresser Messier 8" Dobsonian advantage · Amber highlight: Bresser Messier N-150/750 advantage · Greyed cells: equal or subjective.