Welcome to the hobby!
Everyone has different advice for new people. This is written from the perspective of someone who was a newbie and went through the learning curve. The standard advice if you are very new to astronomy is to grasp some of the basics first: learn where the constellations are, see what you can with your eyes or with binoculars, find a local astronomy group, talk to the members and look through their telescopes. This is all quite sound advice. It makes sense. It is logical. It is not fast. It sounds suspiciously like work.
If you are like the newbies I’ve met (myself included), you’ve suddenly got a passion for the night sky--a ‘fire’ for seeing the magnificence of the heavens. The last thing you want to do is a lot of work and research--boring. So you ask the web and get a battery of answers (including this one) that are:
a. full of opinions, some of them quite strongly held
b. often contradictory
c. not really the answer to the question you had in mind (amateur
astronomers are no better at guessing intent than anyone else).
d. sometimes loaded with jargon you don’t understand, always a danger
in any reasonably technical hobby.
That’s not quite the instant gratification and education you were hoping for. Let’s go back to that little passion. The key thing, first and foremost, is to start observing; keep that new flame alive and add plenty of fuel! So dig out the binoculars that you probably have around and take a look; sweep the Milky Way from your backyard if nothing else. Find that group of amateur astronomers and go to their star parties; go not with the intent of taking “Telescopes 101” but to look through scopes and see what’s up there. All you need to do is show up with a lust for seeing the universe; don’t be shy about having no equipment. I have never yet met an amateur astronomer who wouldn’t fall over backwards to show off what they’re looking at to eager newcomers. (The exception here is the astro-photographers, odd folk who spend forever chained to their scopes, following one astronomical object and mumbling the mantra “No planes, no planes, just this once, no planes”.)
Notice how I have maneuvered you into doing a lot of that “sound advice” stuff in the first paragraph--but as a fun event, not a set of tasks. The rest of it (learning about scopes, getting experience with equipment, starting to find your way around the sky, recognizing constellations, etc.) will occur naturally as you begin to observe.
The day after you’ve found and ogled your first bright open cluster with binoculars, or looked through a scope at the Orion or Lagoon nebulas, that little spark of interest in things astronomical is likely to become a flaming passion. Driven by the desire to know more, you find yourself cruising a bookstore or the web. There are lots of good resources in both places. This is a very basic starting list:
“The Backyard Astronomers’ Guide” (my personal favorite)
“Turn Left at Orion”
The web of course is incredibly connected via links. Because links die regularly, I have listed a few current ones here, but no guarantees. However, if you do a search with appropriate keywords (like: astronomy, amateur, beginner), you will get a very long list of sites. As I write this, Google put these on the first page: http://www.skyandtelescope.com/astronomy-equipment/how-to-start-right-in-astronomy/ http://www.denverastrosociety.org/beginners.html http://www.space.com/14485-skywatching-telescopes-beginners-guide.html http://en.wikipedia.org/wiki/Amateur_astronomy
Telescopes! What do I want?
By now, you probably have a problem; your want gland is throbbing fiercely. You know you want to get a telescope, but you don’t know which one. Let’s start off with one basic fact: no telescope is perfect. If one were, we’d all have it and there’d be no need to fret over a choice. Another key bit of advice is that you are not someone else and have a unique set of needs and wants; what works for another amateur astronomer may not be best for you.
If you can stand a bout of rationality (hard with the want gland out of control), make up a rating table. List all the factors that are important to you. Assign a relative importance to each. Then rate all the candidate scopes for each factor. Imagine AstroDad, a hypothetical father of two elementary school age children. He took them to a few star parties at a local school, and now they and the wife are after him to buy a telescope. He harbors a secret passion for galaxies (having seen some through scopes at the star parties), does not have a very large car, and can scrape together money enough for a basic set up costing to $1200 (but would prefer less). The kids like planets, but he’s not so interested; clusters are sort of nice, though. There’s a place in the basement for storing the scope, and it’s not that hard to get it in and out of there. At the last star party, the kids tried moving a big dob and had some trouble with it. Sitting down with pencil and paper, he writes the following:
Factor's -------------Scope scores-------------
Factor Importance 8” SCT 4” Refrctr. 8” Dob 6” Dob
Cost 10 5 2 8 10
View galaxies 8 10 4 10 7
View planets 5 5 8 6 4
View clusters 6 4 9 4 5
Portability 7 10 8 1* 6
Kids using it 10 6 7 4 5
Storage space 4 8 10 4 6
Gee-whiz neat 1 5 10 4 3
Score -- 346 322 281 325
* requires taking out spare tire to fit in trunk if kids are going
to observing session and thus using the back seat.
AstroDad finds to his surprise that the second-most-expensive scope scores highest (but there isn’t a huge difference in score among the top three contenders). In this example the 8” dob got zorched by its size; if AstroDad's car trunk were two inches taller, he’d have rated it a 6 on portability instead of a 1, giving it 35 more points and a score of 316. AstroDad thinks it over, talks with the family, and in the end chooses the 6” dob due to a late feeling of guilt over the cost of the 8” SCT.
When you do this kind of exercise, your first-pass numbers usually serve to spark a further examination of the choice; don’t be shy about fiddling with the values of the importance factors and doing a few cases. Many people aren’t that sure at first just how important each factor is to them. This kind of rational analysis often makes us think a good deal about what we really want, which is useful in itself.
But the rational-analytical method has one big problem; you have to know enough to be able to fill in meaningful numbers for the telescope scores for each rating factor. It can take a while (going to enough star parties, for example) to acquire the knowledge to do this. If you are sitting there burning up with desire to buy a scope, it chafes on the psyche to have to do research before getting your new instrument. We can be remarkably irrational in such matters; I well remember being consumed with “throb-osis” of the want gland when I started into buying a telescope. Yes, I’d read a couple of books and FAQ’s, and been to some star parties, but I didn’t know scopes that well when the cash was plunked down.
You, like me, may not be able to resist the siren call of the telescope. In that case, buy an 8” scope if you can afford it, and a 6” if you can’t. Why? An 8” scope will show a lot of deep sky objects, so that you will be able to see almost all classes of astronomical objects. That’s key. As a newbie you many have an early idea of what astronomical objects interest you most, but your desires are still forming and may change. A good 8” (of whatever type) will serve pretty well for almost anything: clusters, planets, galaxies, double stars, nebulas. Also, a well-made 8” scope has theoretical sub-arc-second resolution; folks with bigger scopes may see more and fainter objects, but 95% of the time atmospheric instability (called "seeing") limits them to no more fine detail than the 8” scope will present. On those rare occasions of great seeing, the huge reflectors, ultra-refractors and mega-SCT's will “win” big time, but you don’t need to worry about that. "Winning" is not the object here. You’ll have a telescope that can show you thousands of interesting heavenly objects, enough for a lifetime of viewing. If you later come up with a passion for some specialized aspect of the astronomical hobby, you have plenty of time to save for that specific kind of scope without running out of things to do with your 8”. If your budget just won’t allow an 8”, even on a Dobsonian mount, then a 6” Dob. is a good compromise. It won’t show quite as many faint deep-sky objects but is still quite a capable instrument.
Still above the budget? Here I’d suggest saving up for at least a 6” if you can. You do have alternatives. Join an astronomy club; many have club scopes you can use in the meantime. Use the binoculars a little while longer and "steal" a lot of scope looks at star parties. Haunt the used scope market; you may find a perfectly capable beginning scope on the market because its owner bought a shiny, big new one and has to pay for it (the seller will probably be pleased his old reliable is finding a good home).
Buying a smaller scope is another alternative; you will be giving up some flexibility--don’t expect fainter deep sky stuff to show--but for some classes of objects (clusters, star clouds, double stars, some bright nebulae, solar viewing with a special filter, planets) small scopes can be perfectly adequate if well made. That, unfortunately, is a big if. At the low end of the price spectrum, there have to be compromises and some of them are not especially obvious to the prospective purchaser. Be very wary of any telescope sold advertising high magnifications that exceed twice the aperture in millimeters (for example, suspect anything over 160X mag. for an 80mm scope). Advertising overly-high magnification is a come-on used to lure the unknowing, as is including a number of poorly made accessories to make the package look sophisticated and complete. Yet another underhanded marketing trick is to provide a very poor, shaky mount; the general public has no idea of how important stability is to a telescope and is easily misled. Such “trash scopes” are often found as a sideline in sporting goods or department stores. Avoid them. Telescopes are precision instruments, and very price competitive. You will get what you pay for and going below a certain point gets you junk. As I write this, the cutoff for a decent instrument is roughly around $250-$300, new, without accessories.
When planning your budget, you have to count on a few extras. A telescope as delivered will work, but be difficult to use without a few necessary accessories.
You almost certainly have to have some sort of star chart. This is a map of the heavens, and maneuvering around the sky without one is difficult at best. Small atlases start around $15, with the more detailed ones going for about $40 minimum up to $250. A planisphere, a wonderful plastic gadget that shows where in the sky any particular constellation will be at any time of night during any part of the year, is almost a must. Fortunately, it’s inexpensive, about $10. Although they are far from a necessity, a large number of wonderful astronomy computer programs are available. One of these is nice to have and usually comes with a lot of fascinating pictures and all sorts of nifty ways to display the stars, constellations, deep space objects, planets, comets, etc. They're anywhere from $30 for some shareware to $200 for the more graphically-enriched commercial programs.
Most new scopes come with one eyepiece; this is somewhat limiting, rather like having a guitar with one string. One of the great advantages of a telescope is the ability to vary magnification by switching eyepieces. You will probably want 3 eyepieces, or 2 eyepieces plus a 2X Barlow, as a basic minimum set. Eyepieces (and other assorted astronomical gadgets) are a virtually endless source of future birthday and Christmas gift ideas for your relatives to use; don’t feel you have to load up right now. Eyepieces come in a bewildering array of different optical designs and prices from a host of manufacturers and importers. If you are just starting out, stick with good quality Plossl type eyepieces, 1.25” size, in the $70 to $110 (each) price range. Once you have done a some observing and looked through a lot of different types of eyepieces (one of the general amusements among the amateur astronomers at star parties), then you can go for the more exotic types if you find you want them. Some of us (I’m one) are easily parted from our money for wide-field eyepieces like Naglers and Pentax XW’s, but you certainly don’t need them to start. If you have to observe with your glasses on (astigmatism is usually the cause; common near- and far-sightedness can be taken care of by the telescope focusing mechanism), then you may want to spring for eyepieces designed to provide longer eye-relief (the distance from your eye to the eyepiece when you're looking through it). If you must use your glasses, be certain to view through the prospective eyepiece installed on a scope to ascertain comfort before buying.
Most telescopes need to have a finder scope. Shorter focal length scopes (less than 600mm or so) can have a wide enough field of view at low magnifications to serve as their own finder. But the majority of scopes are 900mm and up, and trying to move around the sky with their narrow fields of view (2 degrees or less) is just plain tedious. Finders come in two main classes:
a. Non-magnifying finders, like the Telrad, put a “heads up” display of circles or a dot of red light against the sky, and you can thus tell where the scope is pointed. They are great for quickly moving around from bright star to bright star, but less useful for fainter stars and in light-polluted city skies.
b. Magnifying finders are little refractor telescopes, typically 30mm to 80mm in aperture, designed to be attached to a main telescope. The bigger the aperture the better, but also the more expensive. Forget the 5X24 finders; they are just too small and most are very cheaply made. 6X30 finders are adequate but somewhat dim. 7X50 or 8X50 are good and can be had for about $100-150 including the mounting hardware. Bigger and fancier ones (correct image orientation, illuminated reticles, etc.) are out there if you want to spend the money. Personally I find a correct-image-orientation finder a blessing and well worth having, but you don’t have to have one to start.
You will, unless you live in a desert, need something for keeping dew off the telescope. I see you smirking, but it’s true. Your observing session will end fairly early if you don’t account for this problem. A wide variety of anti-dew items are offered for sale, or you can make your own dew cap from a cardboard ice cream container (for larger apertures) or a tin can (smaller apertures, including your finder scope), some black felt, and a bit of glue--total cost, $10 (not counting the original contents of the container or the can, which you apply to the food budget). If you’re buying something ready-made, expect to spend around $50 or more.
To make life at the observing area comfortable requires proper warm clothes and something to sit on. You can observe without either, but the event is decidedly less fun. Almost everyone has sufficient warm clothes; just be sure to take them with you. A big puffy jacket, pull-over pants (snow pants are great), a warm hat, wool socks, and some gloves (thin ones so you can operate the scope) will definitely help keep the chills away. Even summer nights get cold under a clear sky. For a chair, take whatever is portable. Something height-adjustable is great if you have it, but almost any stable support will work. I used to use a kitchen kick-stool, inelegant but effective. Even a sturdy orange crate is OK, with the added benefit that you can put all your accessories in it during the trip to the observing site. Fancy adjustable observing seats are made for the hobby, but they’re expensive ($150+). You can live without one unless you have something like a bad back. If you go camping, you may have camp chairs and a camp table; these are great for observing as well. The miraculous invention known as the Roll-a-Table is worth having, for spreading out your star charts and not having to bend down time and again all night to pick up eyepieces from your eyepiece case.
Many observers carry a collection of nibbles and munchies to sessions. Don’t forget a water bottle or thermos full of whatever liquid refreshes you, too (but NO alcohol--that interferes with visual acuity).
Time for a review. By now, you should have something like:
telescope and mount
observing paraphernalia (clothes, chair, table, etc)
---and, most importantly---
a burning desire to go out and observe
OK, What Do I Do with All This Stuff?
The best thing to do is go observing with a group of local amateur astronomers. This way you can take advantage of all the scouting they have already done to find the most convenient observing locations with good horizons, minimal dew, no lights, and no legal access problems. Often, they have worked out understandings with landowners or park officials to use good observing areas closed to the general public at night. Moreover, the more experienced amateurs will definitely be a great help at first, both in showing you how to observe (it takes some practice) and what to observe. Astronomy is an old, old art and science; take advantage of the huge amounts of learning that have been accumulated since the beginnings of the telescope era some 400 years ago.
Do not expect to see miraculous views by the dozens your first time out. Getting familiar with your equipment and learning to find celestical objects are skills that take time and practice to acquire. Even with an automated go-to type scope you need some familiarity with how the electronics work and how to set it up using bright stars. Relax. Take your time. One of the joys of this hobby is becoming attuned to the clockwork of the heavens, which move at their own immutable pace no matter what we do down here. You’re going to stumble around for the first few observing sessions. Expect it. Don’t worry about it. Learn from the errors (Who? Me? Polar “aligned” on Kochab instead of Polaris??? Nahhh. Idle rumors...) and go on.
Keep observing. The entrancing views will start to come: brilliant young stars in swirling nebulae, sparkling star clusters, Saturn’s ethereal rings, the dance of Jupiter’s moons. The Universe has no end to its wonders, and they are all out there waiting for you to see them.