Telescope Comparison
Explore Scientific 12" Dobsonian vs Explore Scientific 16" Dobsonian
The price gap is real. The question is whether the extra capability is worth it at your stage.
First light
Explore Scientific · 305mm · £999
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
- 34kg total — designed for a fixed garden or regular dark-sky site, not casual transport
Explore Scientific · 406mm · £1,799
The maximum-aperture visual reflector
- 406mm 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
- 72kg total — designed for a fixed garden or regular dark-sky site, not casual transport
The full picture
The numbers that separate these two scopes — and what they mean at the eyepiece.
Aperture
Explore Scientific 16" 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
Explore Scientific 16" Dobsonian's longer focal length reaches higher magnification with the same eyepiece — better reach for planetary detail. Explore Scientific 12" Dobsonian's shorter focal length gives a wider true field — better for large open clusters and extended nebulae.
Focal ratio
Explore Scientific 16" Dobsonian's faster f/4.5 delivers wider fields with any eyepiece — better for open clusters and large nebulae. Explore Scientific 12" Dobsonian's f/4.99 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)
Explore Scientific 12" Dobsonian's optical tube is 23.0kg lighter. Relevant if you plan to use it on multiple mounts or carry the tube to dark-sky sites separately.
Optical design
Same optical design — differences between these scopes come from aperture, mount, and focal ratio.
At the eyepiece
| Target | Explore Scientific 12" Dobsonian | Explore Scientific 16" Dobsonian |
|---|---|---|
| Planets | ||
| Moon | Excellent 305mm aperture delivers overwhelming lunar detail — sub-kilometre crater features, rilles, and shadow play at high magnification | Excellent 406mm resolves sub-arcsecond lunar detail — tiny craterlets, rilles, and dome structures visible at 300x+ |
| Saturn | Excellent 305mm aperture and 1524mm focal length show the Cassini Division cleanly, globe banding, and multiple moons | Excellent Cassini Division is crisp, cloud banding on the disc visible, Encke gap possible in excellent seeing |
| Jupiter | Excellent Multiple cloud belts, festoons, the Great Red Spot, and moon shadow transits visible in steady seeing | Excellent Multiple belt structures, festoons, GRS detail, and moon shadow transits are richly detailed at 200–400x |
| Mars | Excellent 305mm aperture at 1524mm focal length reveals dark albedo features and polar caps at opposition | Excellent 406mm aperture and 1826mm focal length deliver surface albedo features, polar caps, and limb clouds at opposition |
Deep sky | ||
| Orion Nebula (M42) | Excellent Massive light grasp shows layered nebulosity with hints of colour; Trapezium E and F stars visible on good nights | Excellent Stunning detail in the Trapezium region and nebula structure, though the 1826mm focal length crops the full extent of the nebula wings |
| Andromeda Galaxy (M31) | Moderate 1524mm focal length crops the 3° extent to the bright core and inner dust lanes — full halo is beyond the field of view | Moderate 1826mm focal length shows only the bright core and inner disc — the full 3° extent is well beyond the field of view |
| Open clusters | Moderate Long focal length limits the field of view — larger clusters like the Double Cluster overfill the field, though compact clusters are striking | Moderate Narrow field of view at 1826mm means most open clusters overfill the eyepiece; better suited to compact clusters like M11 |
| Globular clusters | Excellent 305mm resolves individual stars across the full extent of clusters like M13 and M92, including their dense cores | Excellent 406mm resolves individual stars right into the cores of most globulars — M13 and M3 are spectacular |
| Faint galaxies | Excellent 305mm of aperture reveals spiral arms in M51, dust lanes in edge-on galaxies, and populates the Virgo Cluster with dozens of members | Excellent This is the scope's forte — Abell clusters, interacting galaxy pairs, and faint NGC objects become accessible |
| Milky Way / wide field | Not recommended 1524mm focal length produces far too narrow a field for sweeping Milky Way star fields | Not recommended 1826mm focal length produces far too narrow a field for sweeping Milky Way views |
Other | ||
| Double stars | Excellent 305mm aperture gives a Dawes limit of ~0.38 arcseconds; long focal length supports high magnification for tight pairs | Excellent 406mm gives a Dawes limit around 0.29 arcseconds — tight doubles cleanly split, though f/4.5 is less forgiving of seeing than longer focal ratios |
| Astrophotography (planetary) | Good 305mm aperture and 1524mm focal length suit high-resolution planetary video capture, though manual tracking limits frame consistency | Good 406mm aperture and 1826mm focal length are excellent optically, but the untracked Dobsonian mount limits capture to short video clips — still usable for lucky imaging with a high-speed camera |
| Planetary nebulae | Not applicable | Excellent The combination of large aperture and high magnification reveals internal structure, colour, and central stars in objects like NGC 7662, NGC 6826, and the Ring Nebula |
The real tradeoff
Both scopes are capable. The question is which one fits the way you actually observe.
Explore Scientific 12" Dobsonian
- You'll load one solid tube into the car, plonk it on its base, collimate, and be observing in under fifteen minutes — there's no truss assembly, no shroud to fuss with, and no bolts to align in the dark.
- You'll see real structure in the showpiece deep-sky objects — spiral arms in M51, resolved cores in M13 — but Abell galaxy clusters and the faintest planetaries will remain at the edge of detectability, leaving you wondering what another four inches of aperture would show.
- At roughly £800 less than the 16-inch, you keep budget for a coma corrector, a quality 2" eyepiece, and a collimation tool — accessories that transform the view through this scope far more than the bare mirror alone delivers out of the box.
Explore Scientific 16" Dobsonian
- You'll spend twenty to thirty minutes assembling truss poles, attaching the shroud, and collimating before you see a single photon — and you'll do it every session, because the truss design means nothing stays aligned in transport.
- You'll be rewarded with views that simply don't exist in smaller scopes: Abell galaxy clusters emerging as fields of individual smudges, colour in planetary nebulae, the Encke Gap on Saturn's rings on your best nights — this is where visual astronomy stops feeling like a hobby and starts feeling like discovery.
- You'll need a second person or a well-rehearsed loading strategy to get the 35–40 kg of mirror box, rocker base, and truss poles to a dark site — this scope punishes spontaneity and rewards the observer who plans sessions days in advance.
The dark side
Every scope has a personality. Here’s where each one gets difficult.
Explore Scientific
Explore Scientific 12" Dobsonian
At f/5, coma is clearly visible at the edges of wide-field eyepieces — budget £100–£200 for a coma corrector or you'll be frustrated every time you use a 30mm+ eyepiece.
The solid tube weighs 15–17 kg before you add the base, which means a one-person carry is possible but unpleasant — you won't be grabbing this on a whim for a quick look.
Cool-down for the 12-inch mirror runs 30–60 minutes, and without a rear fan the thermal currents visibly degrade planetary detail for the first part of every session.
Explore Scientific
Explore Scientific 16" Dobsonian
Coma at f/4.5 is worse than the 12-inch — edge-of-field stars look like little comets, and a Paracorr-class corrector (£200+) is essentially mandatory to get the performance you're paying for.
The open truss design requires a light shroud to prevent stray light from washing out contrast, and it may not be included — verify before buying or budget for an aftermarket one.
Cool-down for the 16-inch mirror can exceed an hour, and at 35–40 kg total weight you'll need to plan transport carefully; a spur-of-the-moment session with this scope is a fantasy, not a plan.
Which is right for you?
Two different buyers. Two different right answers.
The maximum-aperture visual reflector
Explore Scientific · Explore Scientific 12" Dobsonian
You've outgrown your 8-inch and you want to see real galaxy structure — spiral arms, dust lanes, resolved globular cores — without turning every observing session into a logistics exercise. You're happy to drive to a dark site, but you want to load up in one trip and be observing quickly. You value the £800 savings because it lets you invest in the eyepieces and accessories that actually make 12 inches of aperture sing. This isn't for you if you've already seen M51's arms through a friend's big Dob and felt underwhelmed, or if you primarily observe from a light-polluted backyard where much of the 12-inch advantage goes to waste.
The maximum-aperture visual reflector
Explore Scientific · Explore Scientific 16" Dobsonian
You're a committed visual observer who already owns dark-sky knowledge, a collimation routine, and a vehicle big enough to carry serious equipment — and you want to see things that most amateur telescopes physically cannot show you. You'll track down Abell clusters, hunt Shakhbazian galaxy groups, and tease colour out of planetary nebulae that smaller scopes render as grey dots. You accept that every session starts with assembly, collimation, and cool-down as the price of admission. This isn't for you if you're new to Dobsonians, if you observe alone and can't comfortably handle 35+ kg of equipment, or if you mainly want quick planetary looks from the back garden — you'll resent the setup time long before you appreciate the aperture.
Our verdict
At £999 versus £1,799, the Explore Scientific 16" Dobsonian costs 80% more. It delivers 101mm more aperture — a real and visible advantage on faint targets.
If budget is a genuine constraint, the Explore Scientific 12" Dobsonian will make you a happy observer. The Explore Scientific 16" 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 Explore Scientific 12" Dobsonian, use it for a year, then upgrade knowing exactly what you want.
Explore Scientific 12" Dobsonian
View Explore Scientific 12" Dobsonian →Explore Scientific 16" Dobsonian
View Explore Scientific 16" Dobsonian →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 | Explore Scientific 12" Dobsonian | Explore Scientific 16" Dobsonian |
|---|---|---|
Apertureⓘ The most important spec — bigger = more light = better views | 305mm | 406mm |
Focal Length Longer = more magnification potential | 1524mm | 1826mm |
Focal Ratio Lower f-number = wider field of view; higher = more magnification per eyepiece | f/4.99 | f/4.5 |
Optical Design The type of optics — each design has different strengths | Dobsonian | Dobsonian |
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 | Explore Scientific 12" Dobsonian | Explore Scientific 16" Dobsonian |
|---|---|---|
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 | Explore Scientific 12" Dobsonian | Explore Scientific 16" Dobsonian |
|---|---|---|
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 (10:1 reduction) | Dual-speed Crayford (10:1 reduction) |
Size & weight
| Spec | Explore Scientific 12" Dobsonian | Explore Scientific 16" Dobsonian |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 22kg | 45kg |
Total Weightⓘ Full setup including mount — this is what you lug to the car | 34kg | 72kg |
Tube Length | 1500mm | 1826mm |
Tube Material | Steel | Steel (truss-tube construction) |
What's in the box?
| Spec | Explore Scientific 12" Dobsonian | Explore Scientific 16" Dobsonian |
|---|---|---|
Eyepieces Included eyepieces — more is better, but quality matters more than quantity | 25mm eyepiece | 25mm eyepiece |
Finder Scope Helps you locate areas of the sky before switching to the main eyepiece | 8x50 right-angle finder | 8x50 right-angle finder |
Diagonal Tilts the eyepiece 90° for comfortable viewing — useful on refractors |
Blue highlight: Explore Scientific 12" Dobsonian advantage · Amber highlight: Explore Scientific 16" Dobsonian advantage · Greyed cells: equal or subjective.