Welcome to the only telescope buying guide you’ll need. Buying your first telescope should be exciting. Instead, for most people, it’s a confusing spiral through forum arguments, spec sheets, and the creeping suspicion that whatever you choose will be wrong. I know, because I’ve been there — staring at a comparison table at midnight, wondering what “focal ratio” means and whether it matters.
It does matter, but not as much as the forums would have you believe. This guide cuts through the noise and gives you everything you actually need to make a good decision. No gatekeeping, no assumption that you already own three eyepieces and a star atlas.
Telescope Buying Guide: The One Rule That Matters
If you remember one thing from this entire guide, make it this: the most important specification on any telescope is aperture — the diameter of the main lens or mirror. It’s measured in millimetres or inches and determines how much light the telescope collects.
More light means brighter images, more detail, and the ability to see fainter objects. A 150mm (6-inch) telescope will show you things a 70mm scope physically cannot, regardless of how much you spend on eyepieces or how high the magnification goes.
This is why you should be deeply suspicious of any telescope that leads with its magnification. “525x POWER!” on the box is a marketing trick. Yes, you could technically push the magnification that high, but the image would be a dim, blurry mess. Useful magnification tops out at roughly 2x per millimetre of aperture — so a 70mm scope is realistically limited to about 140x.
The Three Main Telescope Types
I’ve written a full breakdown of telescope types, but here’s what you need to know for buying purposes:
Refractors use a lens at the front to gather light. They’re the classic “telescope” shape — a long tube you look through from the back. Pros: low maintenance, sharp images, good for the Moon and planets. Cons: you get less aperture per pound than other types. A 90mm refractor costs roughly the same as a 130mm reflector. Best for: beginners who want simplicity and don’t mind a smaller aperture.
Reflectors (Newtonians) use a mirror at the back of the tube instead of a lens. Pros: much more aperture per pound, great for seeing fainter deep-sky objects. Cons: they need occasional collimation (mirror alignment), and the tube is open, so dust can settle on the mirror. Don’t let collimation scare you — it sounds technical but it’s a five-minute job once you’ve done it a couple of times. I’ve written a guide to collimation that should help. Best for: anyone who wants the most light-gathering power for their budget.
Dobsonians are reflectors on a simple swivel base rather than a tripod. They’re the best value in astronomy, full stop. A 6-inch or 8-inch Dobsonian gives you an enormous aperture for a surprisingly low price, and the mount is intuitive — just push and swivel. The downside is that they’re big and heavy. An 8-inch Dob isn’t something you casually carry to the garden. Best for: anyone with storage space who wants the maximum sky-viewing capability per pound.
What About the Mount?
The mount is the thing the telescope sits on, and beginners consistently underestimate how much it matters. A brilliant telescope on a wobbly mount is an exercise in frustration — every time you touch the focuser, the whole image shakes and takes five seconds to settle.
There are two main mount types:
Alt-azimuth (alt-az) moves up/down and left/right, like a camera tripod. Simple, intuitive, and the best choice for most beginners. Dobsonian mounts are a type of alt-az.
Equatorial (EQ) is tilted to align with Earth’s axis of rotation. Once aligned, you can track objects across the sky by turning a single knob. This sounds useful, and it is — but equatorial mounts are heavier, more complicated to set up, and confusing at first because the controls don’t move in the directions you’d expect. I’d suggest learning on an alt-az and moving to EQ later if you get into astrophotography.
For more on this, see my guide to aligning a telescope mount.
Setting Your Budget
Here’s roughly what to expect at each price point in the UK:
Under £100: You’re in toy territory for the most part, but there are a few exceptions. The Sky-Watcher Heritage 76 is a small tabletop reflector that actually works. It won’t blow your mind, but it’ll show you the Moon’s craters and Jupiter’s moons. Good for testing whether you enjoy stargazing before committing more money.
£100–£200: This is where it gets interesting. A Celestron AstroMaster 70AZ or a Sky-Watcher Heritage 100P or 130P will show you Saturn’s rings, Jupiter’s cloud bands, the Orion Nebula, and lunar detail that’ll make your jaw drop. I’ve reviewed the best options in this range in my best telescopes under £200 guide.
£200–£400: The sweet spot for a serious beginner. A 6-inch Dobsonian like the Sky-Watcher Skyliner 150P lives here, and it’s the telescope I’d recommend most often. Enough aperture to show you galaxies, nebulae, and planetary detail that cheaper scopes can’t match.
£400–£800: An 8-inch Dobsonian or a quality 5-inch refractor. This is where “beginner” equipment starts to overlap with “intermediate,” and the views are genuinely stunning. But it’s a lot of money if you’re not sure you’ll stick with it.
My honest advice: start in the £100–£200 range. If you’re still going outside six months later, upgrade with confidence. If you’re not, you haven’t lost a fortune.
What to Avoid
Some quick red flags when shopping:
Anything sold primarily on magnification. “525x power!” means nothing useful. Look at aperture instead.
Department store telescopes. The ones with stock photos of nebulae on the box. They’re typically low-quality optics on shaky tripods with terrible eyepieces. The images they show on the packaging are from the Hubble Space Telescope, not from the scope in the box.
Tiny refractors on tall tripods. If the tripod is taller than the telescope tube, the mount is almost certainly too flimsy. Any vibration takes ages to settle, and you’ll spend more time waiting than observing.
Bird-Jones designs. These are short-tube reflectors with a corrector lens. They’re cheap for a reason — the optics are usually poor, and they’re a nightmare to collimate. If the tube seems suspiciously short for its stated focal length, it’s probably a Bird-Jones.
Essential Accessories (and Non-Essential Ones)
Most telescopes come with one or two eyepieces, and they’re usually adequate to start. But there are a few things worth adding early on:
A Moon filter (£8–15): The Moon through a telescope is bright. Really bright. A neutral density Moon filter screws into your eyepiece and reduces the glare so you can see detail without squinting. Cheap and genuinely useful.
A red LED torch (£5): Essential for preserving your night vision while reading star charts or adjusting your scope. Your phone’s “red filter” mode works too, but a dedicated torch is better.
A planisphere or star chart app: You need to know where to point the telescope. Stellarium is free and excellent.
Things you don’t need yet: Barlow lenses (the one included is usually mediocre), filters for anything other than the Moon, motorised tracking, or a laser collimator. All of these become useful later, but they’re not where your money should go on day one.
Where to Buy
In the UK, specialist astronomy retailers like First Light Optics, Rother Valley Optics, and Harrison Telescopes offer better advice and service than Amazon. They stock reputable brands (Sky-Watcher, Celestron, Meade, Bresser) and can help if something’s not right.
That said, Amazon is fine for accessories like Moon filters, red torches, and phone adapters. Just be careful with the actual telescopes — the reviews are full of people who don’t know what they’re looking at, so a 4.5-star rating doesn’t necessarily mean much.
Second-hand is also well worth considering. Telescopes don’t really wear out, and the UK astronomy community has active forums and Facebook groups where people sell well-maintained kit at significant discounts. Stargazers’ Lounge and the UK Astronomy Buy & Sell group are good starting points.
For current UK pricing and stock, I recommend checking First Light Optics — they’re a specialist UK retailer with excellent service.
Final Thoughts
Don’t overthink this. The best telescope is the one you’ll actually use. A modest scope that comes outside with you every clear night will show you more than a high-end rig that stays in the spare room because it’s too heavy to set up.
Start simple, learn the sky, and upgrade when you know what you want. And if you get it slightly wrong — welcome to the club. We all do. That’s how you learn what matters to you.
This telescope buying guide covers everything you need, but don’t let the details overwhelm you. The best advice in any telescope buying guide is simple: buy something in your budget, take it outside, and start learning. You can always upgrade later.
Clear skies.
Daniel is a self-taught astronomy hobbyist based in the north of England. He writes honest telescope guides, gear reviews, and stargazing advice — and remembers what it's like to not know a refractor from a reflector.