Dobsonian Telescope for Beginners: Which Size to Buy

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The short answer: the best Dobsonian for most beginners is the biggest one you will still carry out routinely. An 8-inch (Sky-Watcher Classic 200P) gives the best views for the money if you can manage two trips; a 6-inch (Classic 150P) is the one-trip choice; and if you live in a flat, a tabletop 130 or 150 mm Heritage fits in a cupboard. The rest of this page shows how to decide.

Go and measure two things before you read any further: the width of the widest doorway between your storage space and the outside, and the length of your car’s boot with the rear seats up. Those two numbers will choose your Dobsonian more reliably than any specification comparison, because a Dobsonian is the one telescope design where the optics are cheap and the logistics are the real price.

The reason is structural. A Dobsonian is an ordinary Newtonian reflector sitting in a pivoting box — no polar axis, no counterweights, no precision head — so the money that would normally go into engineering a mount goes into mirror diameter instead. That is why an 8-inch Dobsonian costs what a 4-inch refractor on a decent tripod costs. It is also why the aperture ladder in this design climbs faster than your ability to carry it, and why the interesting question is never “how big can I afford?” but “how big will I still be willing to move in January?”

The aperture ladder, priced in handling

One property is shared by every manual Dobsonian on this page and it is easier to state once: none of them follow the sky. At low power an object sits in the field for a few minutes; at high power you develop a small unconscious nudge every so often, which most observers stop noticing after a week or two of use. Only the motorised model at the end of this list behaves differently.

Rung by rung

Heritage 130P — the cupboard rung

The Heritage 130P exists for people who have nowhere obvious to keep a telescope at all. The tube telescopes down to roughly half its length, the whole instrument goes on a shelf beside the coats, and it travels on a car seat without a second thought. For flats, terraced houses and anyone who has to carry a telescope down a communal stairwell, this is the rung that makes the hobby possible at all.

What it needs from you is a surface. A patio table, a garden stool or an upturned crate at roughly seated height turns it into a proper telescope; on the ground it is unusable, and a wobbly plastic table will undo the steadiness the Dobsonian base gives you. It is also the least rigid instrument here, so the focuser feels coarser than on a solid tube, and the truss structure means you should read the open-tube note below. The rest of its trade-offs as a first telescope are worked through in best telescope for beginners.

Check the Heritage 130P

Heritage 150P — same cupboard, one rung up

Six inches of aperture that still collapses and still stores indoors is a real bargain, and the Heritage 150P is the most capability most flat-dwellers can realistically keep. Faint objects respond to the extra glass in a way that is obvious the first time you compare them side by side.

The cost is mass. It is enough heavier than the 130P that the table underneath it starts to matter: a light aluminium garden table transmits your fingertips straight into the eyepiece, so you want something with weight in it. Two hands to carry, rather than one.

Check the Heritage 150P

Classic 150P — the one-trip rung

150 mm, 1200 mm focal length, f/8, solid tube, floor-standing base.

The most underrated Dobsonian in the range, and the reason is logistics rather than optics: one person picks it up and walks outside with it in a single movement, no table required, nothing to assemble. That is worth more observing nights per year than two extra inches of mirror, and it is the calculation most buyers get wrong. Optically an f/8 is long and slow, which makes it forgiving of cheap eyepieces and excellent on the Moon, planets and double stars.

What you give up: a tall telescope, taller than its aperture suggests, so pointing near the zenith can put the eyepiece at an awkward height unless you sit down. The slow focal ratio also narrows the widest field available to you, so the largest open clusters will not frame completely.

Check the Classic 150P

Classic 200P — the two-trip rung

203 mm, 1200 mm focal length, f/5.9, solid tube, floor-standing base.

Eight inches is where deep-sky observing stops being an occasional novelty. The mirror collects around 2.4 times the light of a 130 mm, and the result is qualitative rather than incremental: the Cassini division as a drawn line on steady nights, festoons trailing off Jupiter’s equatorial belt, globulars that stop being a soft ball of light and start looking visibly grainy at the edges, planetary nebulae with structure, galaxies as shapes with brighter cores.

The logistics bill: tube and base travel separately, and the tube alone is an awkward object on a staircase. The mirror wants a while outside before it settles into focus, which rules out a five-minute look on a cold night. Longer tubes hold collimation less patiently, so expect to check it more often than on a tabletop. And no Dobsonian, this one included, will ever do long-exposure imaging.

Check the Classic 200P

Virtuoso GTi 130P — the rung that moves itself

The Virtuoso GTi 130P puts a 130 mm tube on a motorised tabletop base with Wi-Fi, so a phone app slews it to a target and then keeps it centred. High-power observing becomes restful instead of attentive, and showing the sky to a group changes completely when the object stays where you left it between viewers.

The motors are funded out of the same money as everything else, which is why you hold 130 mm here instead of the 200 mm a manual base would have bought. It also needs power and a working phone on a cold night, two more components that can fail; it can be pushed by hand if the battery dies, though that obviously ends the tracking. Worth it for the observer whose bottleneck is finding and holding targets, not for the one who wants maximum photons.

Check the Virtuoso GTi 130P

The open-tube note

Both Heritage models use a collapsible truss rather than a closed tube, which is what makes the cupboard storage possible. The consequence is that the light path is exposed along one side: a porch lamp, a neighbour’s security light or a bright window within your line of sight will lift the background and flatten contrast, in the same way that shooting a photograph into the sun without a lens hood does. Owners solve it with a sleeve cut from a camping mat, a pinned sheet of black craft foam, or simply by observing from the shadow of the house. It is a five-minute fix, but nobody mentions it until you have already noticed the problem.

What Dobsonian owners buy in the first month

• A Cheshire collimation eyepiece, which is not optional on a Newtonian — it is the difference between tight stars and soft ones, and the whole procedure takes five minutes.
• One decent medium-power eyepiece such as a 9 mm Plössl; the two eyepieces supplied in the box are there to get you started rather than to keep. Which focal lengths to add next is covered in best eyepieces for beginners.
• A moon filter, because an 8-inch mirror pointed at a near-full Moon is genuinely dazzling.
• A red flashlight and a planisphere — a manual Dob means you navigate by eye, and both of those make that possible.
• Turn Left at Orion, which functions as the missing manual for a Dobsonian’s first year. Fuller priority order in telescope accessories to buy first.

Three answers worth having before you order

Why are Dobsonians so cheap for their size?

Because you are not buying a mount, you are buying a box. No equatorial head, no gears, no counterweights, no motors — and the money that would have gone there buys mirror diameter instead, which is the component that decides what is visible at all.

How often does one need collimating?

It depends entirely on how it travels. A scope that only ever goes from a hallway to the lawn and back can run a long stretch between checks; the same scope rattling its way to a dark site by road wants looking at most sessions. Short tubes are more tolerant than long ones. Either way the check takes longer to describe than to perform.

Can a Dobsonian do astrophotography?

Partly. Lunar and planetary video works well, because those exposures last milliseconds and stacking software tolerates drift. Deep-sky imaging does not, because a Dobsonian cannot follow the sky’s rotation accurately for minutes at a time — that needs an equatorial tracking mount, covered in best star tracker.

Read next

• Best Telescope Under $300 — the tabletop rungs, priced.
• Best Telescope Under $500 — where the 6-inch and 8-inch rungs sit.
• Best Eyepieces for Beginners — the first upgrade that changes the view.
• Telescopes by Budget.

Also read: Portable telescope for beginners: 5 grab-and-go picks.

How we reviewed this (updated 16 October 2026): this page is based on manufacturer specifications, listing details and public buyer feedback. We have not hands-on tested the products listed.