There is a standard line of advice that is given to beginners entering Astronomy. Some of it is sound, some applies only to certain beginners, and some is questionable.
When a beginner asks “how should I start?”, advice from credible sources such as good books is usually of the following form:
- Don’t rush out and buy a telescope.
- Especially, don’t buy a “department store telescope” or an “eBay telescope”.
- Start with a book, star charts, and your naked eyes, to learn the constellations and some of the major stars.
- Then buy binoculars and use them to look at star clusters and other larger objects.
- Finally, buy a telescope, preferably a mid-sized dobsonian.
Other Common Advice
Other advice frequently added on Internet groups includes statements such as these:
- Aperture Rules!
- I suggest you start with a 12″ Dobsonian.
- Buy the largest telescope you can store and transport.
- You have to buy a <fill in brand here> or you are a fool. I already did the research and there is no other answer.
- Use an alt-az mount. Equatorial mounts are only for photography.
- Don’t buy a “go-to” scope. That’s cheating. You have to learn the sky and learn how to find things by yourself.
Much of that traditional advice is sound, or at least once was. Some, I feel, depends on your situation and may not apply (e.g. I feel the advice should be very different for someone living under dark country skies and someone living in a light-polluted city). And some is just people defending their own opinions, showing their own biases, and making value judgements that should be ignored. Do your research, and make your own decisions.
Here are some thoughts on the first section of advice above.
Don’t rush out and buy a telescope.
Good advice. There are two objectives to this “go slow” advice. One is to ensure you take the time to learn about the sky — the constellations, major stars, and how things move. It’s hard to use a telescope without this knowledge. The second is to avoid disappointment; by going from naked eye to binoculars to telescope, your views get better each step of the way. Many people who buy a telescope immediately after first thinking of astronomy are disappointed because what they see doesn’t match their expectations.
Especially, don’t buy a “department store telescope” or an “eBay telescope”.
Good advice. Department stores, electronics stores, and camera stores sell toy telescopes. They are usually packaged in misleading ways that set incorrect expectations (e.g. pictures of coloured galaxies on the box, and absurd magnification claims) but are, in fact, very low-quality instruments. Typically they are useful only at the lowest magnification for which they are equipped, and work poorly there; worse, they usually have inferior mounts that are difficult to aim and will not hold the scope steady enough for observation.
The same can be said for “eBay telescopes”, which refers to a number of brands of telescope that seem to exist only to be sold on eBay. You can tell these scopes apart from genuine telescopes that happen to be for sale on eBay by looking for certain signs, discussed here.
Start with a book, star charts, and your naked eyes, to learn the constellations and some of the major stars.
This is excellent advice. Learning how the sky works, how it moves, the major constellations, and major stars will make your astronomy hobby much more rewarding.
I’m not convinced this is always good advice though. It assumes your sky is dark enough that you can actually see a reasonable number of stars, and the constellations. If you live in a light polluted city, you won’t see the constellations, and will find naked-eye astronomy very frustrating. You will either have to have the ability to get out of the city, into dark skies, on a regular basis, or you will have to skip this step.
Then buy binoculars and use them to look at star clusters and other larger objects.
Again, I like the idea of gradual progress through equipment sophistication, provided you have access to dark enough skies to be able to navigate and find things.
Binoculars are always useful to have, even after you have progressed to a telescope. They can be used to sweep the sky just as it starts to darken, looking for that elusive first star or planet; they can be used to observe large objects such as M31 that may be too big to fit into the field of view of your telescope; and, of course, they are useful in daytime for other things.
To be useful for astronomy, however, binoculars pretty much have to be mounted on a tripod. You can’t hold them steady enough by hand, and you will quickly tire your arms trying. So budget for a tripod adapter and a tripod if you decide to start with binoculars.
Finally, buy a telescope, preferably a mid-sized dobsonian.
This is the end of the sequence of classic advice. Great advice, especially under dark skies, and with some other conditions.
This advice finally includes a recommended type of telescope. The recommendation of specifically a “mid-sized dobsonian” is for several reasons:
- Dobsonians use very simple mechanics, which means your money is going mainly into optics; you get a good optical instrument for a good price. The same price as the higher-end department store toy telescopes will get you an excellent-quality Dobsonian.
- Basic Dobsonians are simple to point, and use no motors or electronics. This lets you concentrate on learning to find things and on observing, and not get caught up in technology.
However, in my humble opinion, life is not that simple, and Dobsonians are not always the perfect choice for everyone. Some factors might be:
- Dobs are rather large, and you may have physical disabilities or storage limitations that make them impractical. A smaller telescope that you can actually use is a better choice than a large scope you can’t.
- Dobs are rather tall, and the eyepiece is at the top, so it may be 4 feet off the ground or more (up to 20 feet for the monster dobs that serious observers love). If the telescope is for a small child, you may not want to start them with equipment that will require them standing on a stool or ladder to begin observing.
- If you live in a heavily light-polluted area and don’t have access to transport to take your telescope out to the country, you’re going to have trouble finding things, and might need electronic help (a go-to system).
- Not being motorized, Dobs don’t track objects; they must be constantly “nudged”. Personally, I find this makes them less suitable for giving public astronomy demonstrations because I must step in between each visitor to re-aim the scope. When setting up a telescope for someone else to view through, I prefer a motorized mount that keeps objects in the field of view for a long time.
- For many people, however, I agree completely that this is probably the best way to start.
Contrary to the normal advice, I think good quality small to mid-sized refractors and mid-sized Schmidt-Cassegrains are also a good choice for many people.
- If you are confined to a light polluted city you are not likely to see much beyond the easy bright objects, so a smaller telescope will be enough and will be much easier to handle
- If you are interested mainly in planets and bright objects, a refractor will suffice and gives better views of the things it can see at all.
- Schmidt-Cassegrains are an excellent compromise scope that gives a mix of large aperture and high portability, and they usually come on good quality mounts with tracking motors.
- Both SCTs and Refractors place the eyepiece closer to the ground where a small child will find it easier to access.
And some thoughts on the second, “less credible”, section.
Aperture Rules! I suggest you start with a 12″ Dobsonian. Buy the largest telescope you can easily store and transport.
Maybe. It’s certainly true that, all else being the same, a bigger telescope will let you see more than a smaller telescope. But all else is rarely the same. A bigger telescope that you can’t handle, or that won’t fit in your car, or that won’t fit in your observing area, or that takes longer to set up than the free time you usually have available, sees less than a small scope that actually gets used. That’s why I think the last sentence above is better advice: get the biggest scope you can, that you can easily handle yourself.
You have to buy a <fill in brand here> or you are a fool. I already did the research and there is no other answer.
Typical nonsense you’ll see as replies to questions in many Internet discussion groups. Often with misspellings, sentences all in capital letters, and lots of exclamation marks.
There is no single, simple, correct answer to “which scope”, with the possible exception of the advice to avoid department stores. Gather all the information you can, visit some astronomy clubs to try things, and then make your own decision.
Use an alt-az mount. Equatorial mounts are only for photography.
Nonsense. Both mounts have their place, and the question of photography is a red herring. Alt-az mounts can be used for photography (although they are not ideal for it) and Equatorial mounts can certainly be used for visual observation. The difference is a trade-off: easier learning curve for the Alt-Az mount, versus easier tracking of objects in the sky for Equatorial. I have both, and each is my preferred style for a different type of observing.
Try both by visiting some astronomy clubs, and then make your own decision.
Don’t buy a “go-to” scope. That’s cheating. You have to learn the sky and learn how to find things by yourself.
Nonsense. “Cheating”? Is there a rule book?
There are some reasons to avoid starting with a go-to system:
And there are some advantages for certain types of beginners:
Here is some more information on go-to systems.
There is no rule book. Not everyone is interested in looking at the same kind of things, or in spending their limited hobby time in the same way.
Although larger diameter telescopes will, in theory, show you more, a telescope that is too large for you to easily use will show you less because you won’t use it.
There isn’t a single correct answer to “which telescope should I buy”. Telescope and mount selection is a question of making the trade-offs that best suit your situation. The best thing you can do is read some good books and find a local astronomer for advice, then look at your own interests and situation, and make your own decision. It’s unlikely that you’ll regret it, and you can always sell to another beginner and trade up when you’re ready.
If you would like my personal advice, for your consideration, it’s here.