Telescope Comparison
Bresser Messier AR-102 vs Vixen A80Mf
The specs are close. The experience isn't.
First light
Bresser · 102mm · £299
The sky-learner's equatorial scope
- 102mm refractor 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
Vixen · 80mm · £329
The simple alt-az visual scope
- 80mm refractor on a simple alt-az mount
- Good for: Moon, planets, bright open clusters
- No alignment required — quick to set up, intuitive to move
- Finding objects requires learning to star-hop: navigate with a finder scope and sky chart
- 6kg total — manageable to carry to dark-sky sites
The full picture
The numbers that separate these two scopes — and what they mean at the eyepiece.
Aperture
Bresser Messier AR-102 gathers 1.6× 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
Vixen A80Mf's longer focal length reaches higher magnification with the same eyepiece — better reach for planetary detail. Bresser Messier AR-102's shorter focal length gives a wider true field — better for large open clusters and extended nebulae.
Focal ratio
Bresser Messier AR-102's faster f/6.47 delivers wider fields with any eyepiece — better for open clusters and large nebulae. Vixen A80Mf's f/11.38 provides more magnification per eyepiece — better for fine planetary detail.
Mount type
Bresser Messier AR-102's equatorial mount tracks the sky when polar-aligned. Vixen A80Mf's alt-az is simpler to set up but objects drift at high magnification.
Weight (OTA)
Vixen A80Mf's optical tube is 1.4kg lighter. Relevant if you plan to use it on multiple mounts or carry the tube to dark-sky sites separately.
Optical design
Both are refractors — no mirrors to collimate, good contrast, colour-free stars with ED or APO glass. The differences between them are in aperture, focal ratio, and glass quality.
At the eyepiece
| Target | Bresser Messier AR-102 | Vixen A80Mf |
|---|---|---|
| Planets | ||
| Moon | Excellent 102mm aperture delivers sharp crater detail; some purple fringing at the bright limb from the achromatic design, reduced with a fringe-killer filter | Excellent 80mm aperture and f/11.4 focal ratio deliver sharp, high-contrast lunar detail — craters, rilles, and terminator shadows are crisp with minimal chromatic aberration. |
| Saturn | Good Rings clearly separated from the disc, Cassini Division visible in steady seeing; chromatic aberration softens the image above 130× | Good 910mm focal length and clean optics show rings clearly separated from the disc; Cassini Division visible in good seeing. |
| Jupiter | Good Two main equatorial belts and the four Galilean moons are easy; further belt detail limited by chromatic aberration at this focal ratio | Good Two equatorial belts and Galilean moons well defined; the long focal ratio rewards patience in steady seeing. |
| Mars | Moderate Disc and polar cap visible near opposition, but the short focal length and chromatic aberration limit surface detail | Challenging Small disc visible at opposition with possible polar cap hint, but 80mm aperture limits surface detail. |
Deep sky | ||
| Orion Nebula (M42) | Excellent 102mm at f/6.5 shows the full nebula extent with bright wings and the Trapezium resolved cleanly | Excellent Bright nebula core and trapezium stars well shown at 80mm, though the 910mm focal length crops the nebula's full extent. |
| Andromeda Galaxy (M31) | Excellent 660mm focal length frames the bright core and inner halo in one field; 102mm aperture helps reveal dust lane hints under dark skies | Moderate 910mm focal length shows only the bright core region — the galaxy's halo extends well beyond the field of view. |
| Open clusters | Excellent Wide field and 660mm focal length are ideal — the Double Cluster, Pleiades, and M35 all fit comfortably | Moderate Narrow field at 910mm means many clusters overfill the eyepiece; compact clusters like M35 fare better than the Pleiades. |
| Globular clusters | Moderate M13 and M3 appear granular at the edges; core remains unresolved at 102mm | Moderate M13 and M3 appear as granular fuzzy balls — 80mm cannot resolve individual stars in the cluster. |
| Faint galaxies | Moderate Brighter Messier galaxies like M81/M82 visible as fuzzy patches; insufficient aperture for detail in fainter targets | Challenging 80mm aperture limits detection to brighter Messier galaxies as faint smudges; detail is not visible. |
| Milky Way / wide field | Good 660mm focal length gives wide fields at low power; slightly longer than the ideal ≤400mm for sweeping but still very effective for rich star fields | Not recommended 910mm focal length produces far too narrow a field for Milky Way sweeping or rich star field context. |
Other | ||
| Double stars | Good 102mm resolves to ~1.1 arcsecond; the fast focal ratio and chromatic aberration reduce contrast on close bright pairs compared to a longer f/ratio scope | Excellent The f/11.4 focal ratio produces clean, tight Airy discs — ideal for splitting doubles down to the ~1.5 arcsecond Dawes limit. |
The real tradeoff
Both scopes are capable. The question is which one fits the way you actually observe.
Bresser Messier AR-102
- You'll set up the equatorial mount with counterweights and spend a few minutes roughly polar aligning — it's not grab-and-go, but once aligned, sweeping along the Milky Way with that wide 3° field feels like the scope was built for exactly this.
- You'll find the Double Cluster, the full wingspan of the Orion Nebula, and the Andromeda Galaxy's halo all fit comfortably in the eyepiece — the short 660mm focal length rewards you for pointing at big, sprawling targets rather than zooming in on planets.
- You'll notice purple fringing creep in on Jupiter's limb and the bright edge of the Moon once you push past about 120×, and you'll learn to keep magnification moderate — this scope rewards restraint, not ambition at the eyepiece.
Vixen A80Mf
- You'll have the scope on its alt-az mount and observing within minutes — no counterweights, no polar alignment — and the Porta II's smooth slow-motion controls let you nudge Saturn back to centre without the view shaking.
- You'll spend your evenings tracing lunar rilles and crater chains with a crispness that surprises you for an 80mm scope — the long f/11.4 ratio keeps chromatic aberration in check in a way the faster Bresser simply cannot match on bright targets.
- You'll feel the 80mm aperture limit the moment you turn to deep-sky — the Pleiades overfill your field, M13 stays a fuzzy blob, and faint galaxies barely register — so you'll naturally gravitate back to the Moon, planets, and double stars where this scope shines.
The dark side
Every scope has a personality. Here’s where each one gets difficult.
Bresser
Bresser Messier AR-102
The achromatic doublet at f/6.5 produces noticeable purple fringing on bright targets above roughly 120×, making high-magnification planetary views softer and lower-contrast than the Vixen's slower f/11.4 design.
The equatorial mount ships without a tracking motor, so at higher magnifications objects drift out of the field quickly — and the tube is near the mount's practical weight limit, meaning adding a camera or heavy eyepieces can introduce vibration.
The included 26mm and 9mm Plössl eyepieces have narrow apparent fields; you'll want to budget for at least one wide-angle eyepiece to unlock the wide-field potential the short focal length is designed to deliver.
Vixen
Vixen A80Mf
The 910mm focal length yields a narrow true field of view — large objects like the Pleiades and the full extent of the Orion Nebula are cropped, and Milky Way sweeping is essentially off the table.
At 80mm aperture, faint deep-sky targets are out of reach: you won't resolve individual stars in globular clusters, and dim galaxies beyond the Messier showpieces will be invisible or featureless.
There's no motor drive or GoTo, so astrophotography is limited to brief smartphone snapshots of the Moon and planets — and the supplied PL 20mm and PL 6.3mm eyepieces are basic enough that upgrading noticeably improves the experience.
Which is right for you?
Two different buyers. Two different right answers.
The sky-learner's equatorial scope
Bresser · Bresser Messier AR-102
You'll love the Bresser AR-102 if your idea of a great night is sweeping wide swathes of the Milky Way, hopping between open clusters, and soaking in the full expanse of nebulae like M42 and galaxies like M31. You want an equatorial mount you can learn on, you don't mind the setup time with counterweights and rough polar alignment, and you're happy to keep magnification moderate rather than crank it up on planets. This isn't for you if crisp, high-contrast planetary detail matters most — the chromatic aberration at f/6.5 will frustrate you — or if you want something you can carry outside and be observing in two minutes.
The simple alt-az visual scope
Vixen · Vixen A80Mf
You'll love the Vixen A80Mf if you want to grab a telescope, set it up in minutes on a smooth alt-az mount, and spend the evening tracing every crater wall on the Moon or splitting double stars at high magnification with clean, colour-free views. The long focal ratio rewards patience and detail-oriented observing, and the Porta II mount makes tracking at 150× genuinely pleasant. This isn't for you if you want to chase faint galaxies and sprawling nebulae — the 80mm aperture and narrow field will leave you wanting more light and more sky in the eyepiece.
Our verdict
At similar price points, these scopes offer different amounts of aperture per pound. The Bresser Messier AR-102 gives you more light-gathering for your money — and for visual observing, aperture per pound is the most useful single metric.
For pure optical value, the Bresser Messier AR-102 is the stronger pick. The Vixen A80Mf compensates with other features — decide whether those trade-offs justify the premium. If I had to choose: the Bresser Messier AR-102 — more aperture per pound means more sky.
Bresser Messier AR-102
View Bresser Messier AR-102 →Vixen A80Mf
View Vixen A80Mf →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 AR-102 | Vixen A80Mf |
|---|---|---|
Apertureⓘ The most important spec — bigger = more light = better views | 102mm | 80mm |
Focal Length Longer = more magnification potential | 660mm | 910mm |
Focal Ratio Lower f-number = wider field of view; higher = more magnification per eyepiece | f/6.47 | f/11.38 |
Optical Design The type of optics — each design has different strengths | Refractor | Refractor |
Coatings Better coatings = more light transmission through the optics | Fully multi-coated achromatic doublet | Multi-coated achromatic doublet |
How do you point it?
| Spec | Bresser Messier AR-102 | Vixen A80Mf |
|---|---|---|
Mount Type The mechanical system that holds and moves the telescope | Equatorial | Alt-Az |
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 AR-102 | Vixen A80Mf |
|---|---|---|
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 AR-102 | Vixen A80Mf |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 3kg | 1.6kg |
Total Weightⓘ Full setup including mount — this is what you lug to the car | 9.5kg | 6kg |
Tube Length | 660mm | 910mm |
Tube Material | Aluminium | Aluminium |
What's in the box?
| Spec | Bresser Messier AR-102 | Vixen A80Mf |
|---|---|---|
Eyepieces Included eyepieces — more is better, but quality matters more than quantity | 25mm and 10mm eyepieces | 25mm eyepiece |
Finder Scope Helps you locate areas of the sky before switching to the main eyepiece | 8x50 optical finder | 6x30 optical finder |
Diagonal Tilts the eyepiece 90° for comfortable viewing — useful on refractors |
Blue highlight: Bresser Messier AR-102 advantage · Amber highlight: Vixen A80Mf advantage · Greyed cells: equal or subjective.