The last few years have seen a huge resurgence of interest in astronomy - fuelled by popular scientists like Brian Cox and events like Stargazing Live. Observatories and local clubs are working hard to help kids and adults experience the cosmos. If you’re keen to get involved, the good news is that great telescopes have never been so affordable.
Here we’re focusing on telescopes for astronomy, rather than terrestrial viewing or bird-watching, though some models can do both. We’re also concentrating on more affordable models: if you’re splashing out a few thousand pounds on a serious scientific instrument, you’ll need more detailed technical advice.
You don’t need to spend nearly that much to see amazing things, however. Even with a budget ‘scope, you can see details of the moon, Jupiter and Saturn, and a range of nebulae and clusters. You might not attain the kind of Hubble-level views you’ll see on TV, but you’ll get the very special experience of exploring the universe with your own eyes.
How to buy the best telescope for you
What types of telescope are there?
Telescopes come in two basic types: reflectors and refractors. A reflector telescope uses a large parabolic mirror to harvest and reflect the incoming light to another mirror, which in turn reflects that light into the eyepiece. A refractor uses one or more lenses to do the same job.
What are the key differences between the two?
Both types have their strengths: refractors are sealed, which means dirt can’t get in and you can get a sharper image, particularly of bright, near-sky objects like the moon or planets. However, they’re more likely to suffer from chromatic aberration, where bright objects – like a star – appear surrounded by a halo of different colours.
Reflectors don’t have this problem, but the mirrors may need to be manually adjusted, and unless you have a special eyepiece, the view will be upside-down. While reflectors are generally better for viewing deep-sky objects (galaxies, nebulae and the rest) they might not offer such clear, bright views of nearer objects and planets.
Are there any other types I should know about?
If you want to get into the details, there are three variations of the reflector. Cassegrain reflectors add a curved secondary mirror to the classic design, which means they’re more compact. Schmidt-Cassegrain or Maksutov-Cassegrain reflectors place a thin lens over the front of the telescope, to combine the advantages of a reflector and a refractor. Finally, Dobsonian reflectors use the standard Netwonian design, but in a larger form with a heavy rotating mount at the base. The design is easy and cheap to manufacture, even with a larger aperture mirror, so Dobsonian reflectors tend to give you a lot of telescope for your money.
Why is aperture size so important when choosing a telescope?
One crucial factor when choosing a telescope is aperture size. The larger the aperture of the primary lens or mirror, the more light the telescope can harvest, and the more objects and detail you’ll be able to see. This is the big advantage of reflector telescopes: it’s much easier and cheaper to make a bigger mirror than a bigger lens. If you’ve got a choice between a refractor with an 80mm objective lens and a reflector with a 114mm mirror, the reflector will – in most cases – give you better views of a wider range of celestial stuff. Move up to a 130mm or 150mm mirror, and the differences only grow.
Does the mount matter?
Most entry-level and mid-range telescopes come with a bundled mount, but the quality varies enormously. A good mount will give you stable views even at high magnifications; with a wobbly one, it may be hard to keep far-off objects in the frame.
If you have that problem, you can always splash out on a better mount. These come in two basic types; the first is called an alt-azimuth (“alt-az”) mount. This has two axes of movement – up and down (altitude) and left and right (azimuth). It’s a simple system, but it has a downside: as the world turns, you’ll need to keep adjusting both the azimuth and altitude to keep what you’re trying to look at in view. This isn’t a problem for ordinary viewing, but it makes things difficult if you’re trying to track an object or photograph it.
The solution is an equatorial mount, in which one of the adjustment axes (the “right ascension”) is set to match the angle of the earth’s rotation; the other, the “declination”, runs perpendicular to it. Once you’ve found what you want to look at, you only need to adjust the right ascension to keep it in view as the earth turns.
It’s also possible to buy a mount with a computerised motor, to automatically drive the right ascension for you and keep things stable. However, this involves a level of work and a fair bit of learning, and you still have the challenge of finding the things you want to look at in the first place. For an easier life, consider a GoTo mount. These work with a dedicated handset (or a companion app) to automatically point your telescope at whatever object you want to view. Some astronomers regard this as cheating, but if you have limited time and want to get the most from your telescope, it’s a sensible idea - though it will inevitably add to your budget.
What other features should I look out for?
All telescopes come with one or more eyepieces; these, along with the focal length of the telescope itself, determine the overall level of magnification you’ll see. Most entry-level to mid-range telescopes will come with two eyepieces, usually one in the 7mm to 10mm range and one in the 20mm to 25mm range; that gives you a good low-magnification eyepiece for general use, and a higher-magnification eyepiece when you want to get in closer.
Telescopes also come bundled with other accessories, such as a star-pointer or red-dot finder to help you get objects in the view, and astronomy books or software to help you get moving. Perhaps the most useful, though, is a 2x Barlow Lens. This attaches to your eyepiece and instantly doubles the magnification, giving you even more choice and power, right out of the box. If you don’t get a Barlow bundled in, consider one as a quick, easy upgrade later.
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The best telescopes to buy
1. Orion 10012 SkyScanner: The best telescope under £100 – and a top pick for beginners
Price:£94
It might be a small, squat-looking telescope on a miniature Dobsonian mount, but the 10012 SkyScanner gives you a lot of aperture for a very reasonable price. With a 100mm parabolic primary mirror and 20mm and 10mm eyepieces, this little beauty can give you great views of the moon and Saturn, plus a selection of stars and deep sky objects - which is more than you can say for the competition. It’s also very easy to set up and use, and can be attached to a standard photo tripod if you fancy taking it away from home. Don’t expect miracles at this price point, but for under £100 this is the best start in astronomy you can get.
Key specs – Type: 100mm reflector; Mount: Mini-Dobsonian alt-az; Eyepieces supplied: 10mm (40x), 20mm (20x); Extras: EZ Finder II finder, Starry Night software
2. Celestron Travelscope 70 Telescope Kit: The best low-cost travel telescope
Price:£67
The Celestron Travelscope hasn’t got the light-gathering power of the Orion SkyScanner, but it’s an extremely portable and versatile telescope; with a 70mm aperture and 10mm and 20mm eyepieces you can still get decent views of the moon and the planets, plus the brighter clusters and nebulae. The best part is that the telescope and (rather flimsy) tripod pack up into a lightweight rucksack, with the whole shebang weighing well under 3kg - so if you live in the city, you can easily take it out of town to somewhere with an unobstructed view and seriously dark skies. It’s a good, very affordable option for novice astronomers; if you want to get slightly more ambitious, an extra £20 gets you a kit with an additional eyepiece and a 2x Barlow lens.
Key specs – Type: 70mm refractor, Mount: Alt-azimuth mount on photographic tripod; Eyepieces supplied: 10mm (40x), 20mm (20x); Extras: Finder, Sky X – First Light Edition software, Custom backpack
3. SkyWatcher Explorer 130M: The best beginner’s telescope for under £200
Price:£184 – Buy from Wex Photographic
The SkyWatcher Explorer 130P is a classic beginner’s telescope, giving you a 130mm parabolic primary mirror for the same kind of price as most 114mm reflectors or 90mm refractors. The Explorer 130M’s real draw though is its motor-driven equatorial mount. This makes it much, much easier to keep objects in the eyepiece, and it’s great for astrophotography, as you can attach a smartphone or a camera to the telescope and get brilliant blur- and trail-free shots. It comes with 10mm and 25mm eyepieces, plus a x2 Barlow lens, giving you magnification options from 36x to 180x, so you can see deep-sky objects and get fantastic views of the moon and planets. If your budget will stretch to it, this is the beginners’ telescope to buy.
Key specs – Type: 130mm reflector; Mount: Motorized equatorial mount; Eyepieces supplied: 10mm (36x), 25mm (90x); Extras: Red dot finder, 2x Barlow lens
4. Orion SkyQuest XT8: The best value telescope for under £300
Price:£292
John Dobson’s classic 1960s telescope design aimed to make high-powered telescopes more affordable, and Dobsonian telescopes still offer the most bang for buck today. The SkyQuest XT8 gives you a whopping 200mm mirror at the bottom of a 1.25m tube at a pretty affordable price. This is a big, heavy telescope, nearly 20kg in weight, but the simple alt-az mount makes it simple to setup and use. With the bundled 25mm eyepiece delivering 48x magnification, you can get impressive views of galaxies, nebulae and other deep-sky objects, or take a more detailed look at Saturn’s rings or the craters on the moon. You simply won’t get better views of celestial objects without spending a whole lot more.
Key specs – Type: 8-inch Dobsonian reflector; Mount: Dobsonian alt-azimuth mount; Eyepieces supplied: 25mm (48x); Extras: EZ Finder II reflex sight, Collimation cap, Starry Night software
5. SkyWatcher Star Discovery 150P: A great telescope for under £400
Price:£358 – Buy from Harrison Telescopes
It’s a little more expensive than the average 150mm reflector, but the Star Discovery 150P comes with an alt-azimuth GoTo mount on a basic tripod - plus a SynScan v4 handset you can use to find any one of nearly 43,000 celestial objects. The 25mm and 10mm eyepieces give you 30x and 75x magnification straight out of the box, giving you superb views of the moon, planets and many nebulae and clusters. Use the bundled 2x Barlow lens and you’ll see even more detail, with a camera adaptor to get you started in astrophotography as well. If you can’t quite afford the Celestron NexStar 6SE, this is the next best thing.
Key specs – Type: 150mm reflector; Mount: Alt-azimuth GoTo mount; Eyepieces supplied: 10mm (75x), 25mm (30x); Extras: SynScan v4 controller, 1.25in rack and pinion focuser, red dot finder