So you want to buy a telescope?
December 19, 2005 10:23 PM   Subscribe

So you want to buy a telescope? Read these pages first.
posted by jiawen (27 comments total)
Oh, and: you should probably get a Dobsonian.
posted by jiawen at 10:24 PM on December 19, 2005

posted by Balisong at 10:52 PM on December 19, 2005

Metafilter: It is not big enough to be as impressive as I might want, and is rather short on knobs, but I can talk fast enough to make up the difference.
posted by lalochezia at 10:59 PM on December 19, 2005

My first scope was from K-Mart in 1984. I think I learned a lot from perseverance, trying to get the darn thing to work right. I did see the Andromedia galaxy and could see Jupiter/Saturn pretty decently. But eventually the tripod head cracked. I let my grandfather (who was an old mechanical codger) take a look at it... he eyed it over, remarked that it was crap pig iron that was unfixable, and went on a tirade about the Japanese hippies that forged the damn thing.
posted by rolypolyman at 11:02 PM on December 19, 2005

Ahh, they don't make grandfathers these days they way they used too :)
posted by -harlequin- at 11:30 PM on December 19, 2005

Amateur astronomy, just another way to broadcast your phallic failure. Prolly cheaper than sport cars though.
posted by kush at 11:33 PM on December 19, 2005

kush: What if you build a cosmic ray telescope, where the phallic bits are too small for any sort of "compensation" role?

A list of all the things that broadcast phallic failure would make interesting reading. I nominate you post an AskMefi on the topic :)
posted by -harlequin- at 11:40 PM on December 19, 2005

If a telescope is a way to broadcast a phallic failure, what does that make of the owner of a binocular telescope?


"I really do want a nice, big, inexpensive but not useless telescope. Err, where'd my wang go? Damn. That sucks. Eh, I still want a humongous telescope."


Another vote for the Dobsonians.

I once was honored to count the rings of Saturn and check out the Ring Nebula and Crab Nebula with my own eyes instead of in some magazine print or jpeg, by climbing up a large ladder and peering through a 24 inch Dobsonian that was something like 18 feet long.

But considering this guy hand built this stupendous, gigantic, usable and even completely portable telescope that Newton or Galileo would have traded anything imaginable simply to peer through for a few evenings for less than something like $1,500 to $2,000 is really something to behold and consider. That's a really big scope for that much money. A Newtonian reflecting telescope that size on a traditional equatorial or azimuth mount would have cost 20-50K or more 15 years ago or so. Plus it wouldn't be portable and would probably require an actual observatory dome to contain the scope and mount.

The main problem with the inexpensive Dobsonians is that they don't lend themselves to motorization and computer control. Or much of anything that requires precision measurements or alignments. Object and inclination tracking is all manual - as the Earth turns, you get to compensate if you want to do any extended viewing. Some people see this as a feature. The term I've heard used to describe Dobsonian owners is "starhopper", as a Dobsonian owner hops from star to star to navigate and seek out known visible objects. The term seems to be spoken with awe, respect and/or derision.

But then, they also call large bore Dobsonians "light buckets".
posted by loquacious at 12:22 AM on December 20, 2005

I believe the general advice is to not to bother buying a cheap telescope from Fry's, Walmart etc.

I pondered getting one a while back, but in order to see anything well you need to get out of the city. Plus for the most part you're only going to see stuff as dots or fuzzy disks. I'd rather go look at the jpgs from the billion dollar scopes.
posted by jeblis at 12:58 AM on December 20, 2005

loquacious: 24 inches! That sounds truly far out. I've heard of people building scopes that big, but jesus. Did he grind his own mirrors? And if so, how? I am very impressed.

Even cheap scopes from Wal-Mart have their place, as mentioned by rolypolyman. They will generally give good views of the bright objects, which consequently are the ones you can usually see in city lights anyway. So it may not be a bad choice for those new to it and living in the city.

BTW, Sky and Telescope recently reviewed some sub-$200 scopes and a few actually came out alright (sorry, can't find web link - it's in the Dec 05 issue). Of the ones reviewed, their pick was the Orion SkyQuest XT4.5 Dobsonian.
posted by newscouch at 1:36 AM on December 20, 2005

I know I shouldn't be doing this so close to Christmas, but here it is. Lust to your heart's content.
A little tip to those new to telescopes and astronomy, a dobsonian telescope is going to be your best bet from a cost standpoint. binoculars are going to be your best investment for stargazing (much wider field so more stars, look for something 7X50 power, not 10X50, you are looking for light-gathering ability, not power.)
Refractors, like the one from K-mart are going to seem good until you peer through a cheap one for about three minutes or so and come away with horrible eyestrain. This is why you should go with a dobsonian, much better light-gathering ability (hence the term 'light bucket') and the power is going to come from the lenses available, which is practically limitless vs. very limited with a cheap K-mart refractor. A good refractor on the other hand is going to be substantially more than a comporable dobsonian telescope.
posted by mk1gti at 4:35 AM on December 20, 2005

I believe the general advice is to not to bother buying a cheap telescope from Fry's, Walmart etc.

Simpler: Never buy a telescope that advertises magnification -- you can achieve magnification with any telescope, given the right eyepieces (and barlows) but it won't let you see anything. So, if someone puts "600x", on the box, this means that marketing is controlling the release on this telescope. Marketers don't know telescopes.

mk1gt1 is dead on -- a big, lightbucket dob isn't your first scope. The best thing to start with is your eyes and a pair of good 7x50 binoculars. These are cheaper than a decent telescope, are useful during the day in case you decide this isn't the hobby for you, and you'll find yourself useing them for a lifetime if you do.

Dobs are nice, but for first timers (who typically go for planets), they're very hard to use. Big dobs are made for faint objects, you need to be good to even find them in the sky, so a big dob as a first scope is a bad idea.

No matter *what* telescope you buy, the mount is critical (another reason to avoid department store 'scopes -- wobbly mounts.) Many telescopes mention the mount by name. A stable mount makes any telescope more useful, an unstable one makes them useless.
posted by eriko at 5:38 AM on December 20, 2005

Also, Orion's website has a really good feature called their 'learning center', a really good resource for your first optics purchase (or 2nd or 3rd or 400th).
posted by mk1gti at 6:13 AM on December 20, 2005

Thanks for the post, jiawen. I've been seriously thinking of getting a telescope for awhile now, although the purchase is still several years off. This is some good advice.

kush, what does it mean if you're a woman and an amateur astronomer, then? Is it better, or worse?
posted by fossil_human at 6:14 AM on December 20, 2005

That (Dec. 2005) Sky & Tel article did point out that in addition to the usual department store junk scopes there are now perfectly good scopes being sold in a number of larger stores, but you really have to find out for yourself which ones they are.

A Dobsonian is a fine scope for beginners and companies such as Orion make good quality Dobs for children as well as adults. Sure you have to point the scope yourself, but if you're a beginner that's generally a good thing, because it means you'll learn your way around the sky. You also spare yourself the setup time of an equatorial mount arrangement and the calibration time of a goto mount. Not to denigrate any mount type--I love using an equatorial and I'm not that experienced as an amateur observer--but the ability to just drag your scope outside and start looking through it is a huge plus. Goto scopes are appropriate for beginners operating under severe light pollution, which makes star-hopping a lot more challenging, but otherwise I would definitely recommend a Dob. It's less expensive, simpler, faster, and will show more to a beginner than other types of telescopes.

On preview, yes, a big Dob is not a good first telescope. I would say 8" or under. Bigger Dobs are harder to transport and also tend to have faster mirrors which are fussier about proper collimation.
posted by Songdog at 6:47 AM on December 20, 2005

Loquacious, they call large bore reflector scopes of any kind "light buckets".

fossil_human, you're very welcome! Also, I'm an amateur astronomer, and a woman, so I suppose it might not be phallic...

Myself, I bought a Meade DS114AT, which has a totally crappy mount, before I'd read all the links I put up. (I speak from experience -- read that stuff before you buy!) I currently have my heart set on an Orion XT6 (um, not the Intelliscope version).
posted by jiawen at 7:55 AM on December 20, 2005

My former girlfriend turned me onto astronomy and since then I've discovered many, many women out there who are into it. It's not a 'guy' thing by any means.
posted by mk1gti at 8:32 AM on December 20, 2005

I have an XT6 myself, jiawen. It's a nice telescope and they keep making little improvements to the design.
posted by Songdog at 9:56 AM on December 20, 2005

jiawen - I have a Meade DS114 as well. Though I bought it about 5 years ago as my first telescope. The mount is indeed crappy, as it kind of renders the electronics useless if the motors can't reliably track. For the past four years I haven't bothered orientating it. I just turn it on and use the motors to manually guide it. But they are decent first telescopes in that you can easily see 6 of the planets and a little bit of detailin objects here and there.

Of course actually getting a decent telescope as your first one you will benefit from a lot less frustration. Unless after buying said telescope you realize the hobby isn't for you.
posted by Phantomx at 11:41 AM on December 20, 2005

Phantomx - if you start with a decent 'scope and then decide that astronomy isn't for you, you can recoup at least *some* of your cost by selling the scope to another astronomer. If you start off with a junky scope, you probably won't be able to sell it. (fwiw, I live with a 15" homemade truss-tube Dob, Mr R's third scope. There's also an Astroscan tucked under the aquarium stand. The AstroScan gets nearly as much use as the Dob, because it doesn't require the same time commitment.)
posted by jlkr at 2:04 PM on December 20, 2005

Phantomx, your description of the DS114's mount is dead-on. I shouldn't complain too loudly, as I got mine on eBay for about $100, but still, it's not a great scope by any measure. When I get a better scope (*cross fingers*), I don't think I'll sell the DS114AT, because it's not really fair to keep circulating that kind of crap. It'd make a good scope to use with kids -- I wouldn't be too upset if they knocked it over or whatever.
posted by jiawen at 3:15 PM on December 20, 2005

Thanks for the great links, jaiwen. I’ve been working myself up to spending too much money for a new telescope. My old six inch reflector is overdue for re-silvering and I want to upgrade to something with more deep-sky potential. Has anyone out there spent some quality time with an 8 or 10 inch MeadeLX200?
posted by Huplescat at 5:10 PM on December 20, 2005

I can't say I've spent time with the Meade, but given my druthers between Meade and Orion, I would check out Orion's scopes first vis a vis the quality to price ratio. Meade is all good and well and everything compared to, say, Celestron, but for what you can pay for Meade or Celestron you can get a much better quality Orion scope. Not that I'm pimping for Orion, I'm jus' sayin' . . .
posted by mk1gti at 9:27 PM on December 20, 2005

I know someone who has an LX200 (or something similar -- anyway, a large-aperture Meade Maksutov-Cassegrain). He said that he's very disappointed in the mount -- even though it's a $2000+ scope, the gears are still made out of plastic. Take that with a grain of salt, though, and check other reviews first, especially if you're sinking that much money into it!

Songdog, it's good to hear more good views on the XT6. Makes me feel like I'm making less of a mistake this time. :)
posted by jiawen at 11:57 PM on December 20, 2005

Great links! Hopefully your efforts will contribute to a decrease in donations to my local society; they tend to get a lot of scopes given to them after Christmas because they're low quality or not right for their intended recipients. Sadly, these scopes don't see as much use as society "extras" as they would if they were cherished personal possessions. Also, since scopes can be expensive, it's best not to commit to too serious a purchase unless one knows, from spending some time doing naked-eye or binocular observing, that standing out and looking up at night is something they're interested in doing more than a few times. There are many excellent books for learning the sky. I like this one.

"The best telescope to get is one you'll use" is a widespread saying because it's true. Though the Dobsonian mount is what John Dobson's best known for, he invented it to solve a specific problem: how to get out there and share the sky with as many people as possible using inexpensive, serviceable, but not necessarily precision equipment.

Folks already stuck with department store reflectors with disappointing views might be able to greatly improve things with some minor, inexpensive fixes [see "Fixing up a Tasco telescope."] Those with faster DS scopes (focal length ~700mm or less) might consider stress-figuring the mirror [PDF file;] though this isn't a minor project and really best if the plans are to keep it as a second scope.

If you're just learning the sky, nothing beats a good pair of binoculars; They're also great for spotting satellites -- though some satellites are brighter than any star and are incredible with the naked eye. I'm happy with my Pentax 10x50s -- YMMV -- but really any pair of binoculars you have can enhance your viewing tremendously. The best ones for a beginner are ones big enough to gather lots of light but small and light enough to hand hold. Mine go everywhere in my car and if I'm just running down to the beach for a quick session they're all I take. At my age a 7x50 would just mean wasted light (7x50 exit pupil is bigger than my eyes'); the tradeoff is that 10x scopes are harder to keep steady. Tripod mounting definitely benefits anything heavier (bigger objectives) or with more powerful magnification.

We urban stargazers are stuck with crummy observing conditions. For many of us this calls for a scope that's easy to transport to darker sites and set up in the field without too much trouble -- smaller scopes excel at this. Y'all have already covered the Dob thing, and they're an excellent choice, but there's another design family worth considering too.

If one's got sufficient self-esteem to be seen with a smaller-aperture scope, Schmidt-Cassegrain and Maksutov-Cassegrain designs also fulfill the portability criterion and can offer excellent optics at reasonable prices. Also, their viewing position (at the back, often perpendicular to the optical axis) can mean more comfortable use -- this can be the difference between a frequently-used scope and one that gets given to Goodwill. The Meade ETX series* (no, the scope isn't really that ENORMOUS) has a not-undeserved reputation as a poor-man's Questar (those very expensive, precision MCTs we all used to drool over in the Scientific American ads.) You can often get a great deal on refurb or overstock ETX's through Meade's factory outlet. Be forewarned; as mk1gti has pointed out, Meade's QC can be dicey (so you might develop a close relationship with customer service) but when the optics are set up right the viewing is excellent.

My (thankfully non-problematic) ETX is the one that goes with me up to the NW corner of Connecticut. How do you know when it's worth making the trip? This site is a great resource for predicting cloud cover, visibility, seeing and darkness.

The links say this but it can't be overemphasized: hooking up with a local astronomical society is great for tapping the knowledge of experienced amateurs before making a purchase decision. It's also an easy way to get behind the eyepiece of a big scope without a huge investment; the one closest to me boasts a 12.5" Newt under a dome and a 25" Dob that gets rolled onto the lawn when conditions are appropriate. Thanks to great strides in mirror production, many amateurs boast scopes with apertures of 16" or greater; they love to show 'em off and many of them do that at the public nights local associations generally have.

You don't need observatory-quality equipment to enjoy the night's wonders. So don't get fooled into thinking you need to drop a ton of money; when that time comes you'll know. For now, don't wait -- Get out there (and look up!)

*The ETX-90 (and higher) -- the ETX-60 through ETX-80 are short focal length, wide-angle refractors that have met with mixed reviews.
posted by Opposite George at 11:59 PM on December 20, 2005

Excellent stuff, Opposite George! Thanks! :)

I recently bought The Backyard Astronomer's Guide. It's a great book, though a little expensive. It has very good, practical, detailed discussions of a lot of issues. What makes a good eyepiece good, telescope recommendations for different budgets, astronomical history and how-tos for almost all the issues newcomers deal with (setting up an equatorial, writing down observing notes, astrophotography, go-to mounts, etc. etc.).
posted by jiawen at 9:57 PM on December 21, 2005

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