Sunday, February 06, 2011

 

Getting Set


With everything you need to begin amateur astronomy in a serious way, that is. I’ve recently gotten a brace of emails from novices picking my brain as to what I would recommend as their first telescope. Should they get the 12-inch Meade SCT or maybe a 6-inch Astro-Physics refractor? And, oh, if only they had the money for a 25-inch go-to Starmaster! The punchline? Most of these folks have never—or at least only briefly—looked through a telescope of any kind.

And I derned well know any of the above telescopes would be way too big and complicated for most newbies. Who would wind up overwhelmed and intimidated in a matter of weeks, if not days. Those beautiful telescopes would take up residence in a closet or go to Astromart, and one more enthusiastic novice would leave our wonderful avocation before hardly getting started.

And it is not just telescopes; the newbies are tugging at my sleeve about eyepieces, asking whether they need Ethoses to start out, or whether they can make do with Naglers for a while. Maybe they should buy two of every Ethos, in case binoviewing begins to seem like a good idea. Should they take out a home equity loan to get the oculars they are sure they must have to get started?

The enquiries from these earnest folks are often on the unintentionally humorous side—two of every Ethos indeed! I try not to laugh, and to gently steer them to the more modest. What hurts, though, are the emails from and conversations with novices of modest means, some of which damn near choke me up. Jane Newbie loves the stars so much and has dreamed of a telescope since she was a girl, but she only has, at best, five or six hundred dollars she can spend on astronomy. Shouldn’t she just forget the whole thing? Give up her dreams of voyaging the cosmos?

Thus, this Sunday’s entry, the topic of which is how you can get set up for serious amateur astronomy without spending serious moola. What we will do here this morning is completely equip you for 500 – 800 smackers, dineros, greenbacks. Which ain’t that hard. One of the most wonderful things about today’s amateur astronomy, U.S. amateur astronomy, is that we are living through a golden age of inexpensive gear.

I say “U.S.” because the price of telescopes in the UK, for example, is still on the outrageous side, though the situation there is better than it used to be. The astro-stuff we have access to on this side of the pond it is not just cheap either; much of it is amazingly good. Stuff that makes the Palomar Junior that got me going look like a buggy whip.

Isn’t it true, though, that you can get going for less than 500 dollars? A lot less? Sure is. Orion sells one of today’s better telescopes of any sort at any price, the StarBlast 4.5-inch mini-dob, for two-hundred dollars. It comes with a couple of eyepieces and even a planetarium program. Hell, you can lowball it even lower. Check out Tony Flanders’ and Josua Roth’s article on one-hundred dollar telescopes in the March 2011 issue of Sky and Telescope.

The catch with the lowest of the low-priced spread? Surprisingly, it’s not optical quality; it’s aperture. The 200 dollar and below range gets you a 4-inch or smaller telescope, which is fine at dark sites and for casual inspection of the Moon and planets, but not really enough for the deep sky if you, like most of us, live there the sky is compromised by light pollution. For that reason, I advise you to not consider a telescope with an aperture of less than 6-inches, and 8-inches is better and recommended.

How about buying used? That is certainly a viable option. 6 – 8-inch telescopes are plentiful on the used market. When amateurs move up in aperture, many of them foolishly sell the “little scope” (which would be perfect on many nights). Where do you find one? Ask around at the local club. Check out Astromart and Cloudy Nights. You can also keep an eye on your local Craigslist. If you’re brave, there is always eBay, though I don’t recommend that. Before buying used, enlist the help and advice of a fellow member of your club. If the scope is local, try to have him/her accompany you when you go to look at it.

For our purposes today, though, we’ll assume you have decided to buy a new six or eight-inch telescope (you probably don’t want to go bigger than that at first) and, very importantly, the accessories you need to accompany it. I’ve seen lots of new amateurs make the mistake of blowing their whole wad on the scope, not leaving money for things like eyepieces and star charts. The result of that is that you have a nice telescope, but it’s compromised at best and useless at worst. At the entry level for serious astronomy, you will need to set aside a minimum of 200 – 250 dollars for the “fixins.”

No matter what sort of gear you have or aspire to, amateur astronomy is and always will be a pursuit for the patient. The original title of this morning’s entry was going to be “The Herschel Project, Night 20.” Alas, ‘twas not to be. The weather reports continued to degrade as last weekend approached. But I am ever optimistic, as most of y’all know, and I did have a brief spell of hope Saturday morning when most prognosticators, including the dadgum Clear Sky Clock, were saying “pretty good till midnight.”

Thus encouraged, I decided I would indeed make tracks for the Possum Swamp Astronomical Society’s Tanner-Williams, Alabama dark site. Mama didn’t raise no fool (despite what some folks might tell you), howsomeever, so I had no intention of dragging out a ton of gear to include the C11 or even the C8 and the Stellacam and all its support equipment. No, this would be a Charity Hope Valentine night. It might be fun, if the sky cooperated, to see how many Herschel Is Charity could conquer.

If you’re a regular reader, you know Charity is my ETX 125PE. She is so named because she and the Sweet Charity of stage and screen could be sisters. Both are kinda cute, but both have a neurotic streak as well as the occasional tendency to foolish behavior and a character flaw or two besides. As I’ve often said, I sometimes expect Charity to collapse in a self-pitying heap on the observing field after I ask for just one more obscure NGC. I must admit, though, that she never has.

Saturday night, Charity was initially very well behaved. Despite not having been out of her case in months and months, her battery-backed clock was dead-on accurate. Once I got everything properly hooked up and Charity in her correct home position, she went right to two good alignment stars, landing close to them. When the alignment was done I requested M42, and Miss Valentine put the Great Nebula smack in the center of a 100x eyepiece field.

In fact, things went so smoothly that I was immediately suspicious. What was the gag? The weather gods answered that. After a quick peep at the Eskimo Nebula, I looked up from the 9mm Expanse eyepiece to see bands of clouds moving in from both west and east. In about fifteen minutes we were completely socked in. I gave it another half hour, threw up my hands, and began to disassemble my little scope.

I don’t know if Charity was miffed about not getting an adequate ration of photons, or whether it was just Charity being Charity, but she turned on me before I could get her off the observing field. With the OTA in the case, I began collapsing the tripod legs. One…two…three…NOPE. One leg resolutely refused to unlock. In fact, the lock knob seemed to be spinning freely. I was able to cram the tripod into Miss D’s Scion Xb with one uncollapsed leg, but not without saying some real bad words.

At home, I diagnosed the problem. Charity’s OTA is fairly decently made. No, it wasn’t perfect when I received it, but that was more due to slip-shod assembly than poor materials. Once I made a few repairs and mods, all was well. The tripod was and is a different story. It is about as cheaply made as a tripod can be. This is especially galling since, when I bought Charity about five years ago, Meade wasn’t exactly giving the ETX 125 away.

Frankly, the tripod has been falling apart from day one. Starting with the springs and washer arrangement a wannabe mechanical engineer “designed” to make the OTA attachment bolts easier to screw in. These springs and washers fell onto the floor the first time I assembled the scope. I threw them in the pea-picking rubbish bin where they belonged. Not long back, the small metal plates that sit inside the tripod legs under the lock bolts, and which are designed to keep the bolts from marring/bending the tripod legs when they are locked down, also fell out. There does not appear to be an easy way to replace them, but their failure doesn’t seem to have made much difference.

Now a lock knob had failed, spinning on its bolt shaft. A knob-head bolt is not an expensive item, but Meade cut to the bone here, even so. The knobs are hollow, and it was a wonder one of ‘em’s brittle plastic hadn’t cracked earlier, as it now had.

What to do? I couldn’t grip the bolt well enough with pliers to back the thing out. All I could do was use a pair of vice grips to break the knob to pieces. That wasn’t difficult—it was ready to fall apart anyway. With the bolt exposed, I was able to back it out. How to fix? I could order something from McMaster-Carr or check Home Depot, but being stingy and impatient I wondered whether there was something lying around Chaos Manor South I could use as a replacement.

As Miss Dorothy will tell you, I never throw telescope parts away. A little cogitating and I recalled I had three legs from an old Synta EQ-4 tripod sitting in the backroom. Would their lock bolts be the same diameter/threading? They were, and I replaced all the Meade bolts with the Syntas. The Synta tripod was cheap, yeah, but it and all its components were of far better quality than the pitiful Meade ETX tripod.

Because of these and the other faux pas the entire ETX tribe is heir to, I cannot recommend these cute little scopes for novices despite their outstanding optics. What do I recommend, then? Glad you asked.

Before you can decide on a specific telescope, you will have to decide on a general type of scope. At this price level, when you are buying new, the obvious choice is “Dobsonian,” a simple Newtonian reflecting telescope on an alt-azimuth mount. Yes, there are some telescopes in our price range on German equatorial, “GEM,” mounts, but most of these little GEMs are too light to be useful. The average novice will find a “point-and-shoot” Dob easier to get friendly with in the beginning, anyway.

Then there is the question of focal ratio. Many beginners get confused and hung up about this, but it is not a huge concern. Focal ratio is the focal length of the telescope divided by its aperture. The smaller the resulting number, the “faster” the scope (that terminology being a hold-over from photography). Slower telescopes, those with f-numbers of 6 and above, offer narrower fields and higher magnifications eyepiece for eyepiece than faster ones. On the good old flip side, they are less deviled by “coma,” a property of all parabolic mirrors which tends to make stars at the edge of the eyepiece field look more like comets than pinpoints. “Slower” telescopes are also less sensitive to collimation, mirror alignment, errors.

Most beginner scopes in our aperture range, six to eight inches, have f-numbers of 6 and higher and don’t display a lot of coma. The StarBlast 6-inch at f/5 is faster than most of the other beginner-friendly scopes, but at f/5 stars still look pretty good at the field edge. If you’re like me, you will find you spend most of your time looking at objects in the center of the eyepiece field, anyway, rather than agonizing about the way the stars look at the edge. Collimation, while important at f/5, is not as critical as it is when you get to f/4.5 or f/4.

You can get “introductory” Dobsonians, 8-inch Dobsonians with solid tubes (as opposed to open, skeletal “truss tubes”), equipped with computer go-to. Unfortunately, these telescopes, Orion’s Synta-made XTg series, at $850 wreck our budget, not leaving us money for even one el cheapo eyepiece. We can afford the next best thing, however; push-to, a.k.a. “digital setting circles,” with Orion’s XTi dobs. “Push to” is just what it sounds like. You, rather than motors, move the telescope toward the target, watching the read-out on a little computer box. When the computer indicates you are on target, the object of your desire should be in the eyepiece.

“But Uncle Rod, isn’t go-to or push-to a bad thing for beginners? Isn’t it better for novices to star hop? To find objects with a finder-scope and a star chart?” Come si, come sa. I star hopped for thirty-five years. Now that I have push-to and go-to, I will never go back to Sky Atlas 2000. But I am more interested in seeing objects than hunting them. You, on the other hand, may find you enjoy the hunt. Which will you like best? If you are not sure, spend some time on the local star party field with your fellow astronomy club members watching how they work and participating.

Above all, beware of embracing star hopping as a hair shirt. You do not need to forego go-to or push-to to be a real amateur astronomer. You will learn the sky anyway. You will need to know the bright stars, at least, in order to align your computer. Even if you don’t need to be able to identify all the constellations, you will find knowing them interesting and rewarding in itself. Bottom-line-time: push-to/go-to will, in the early days, ensure you see enough to keep your interest alive.

Now, down to brass tacks. There are plenty of solid tube Dobsonians out there—if not as many as there were ten years ago—but most of them come from two makers, China’s Synta (Celestron’s parent company) and Taiwan’s Guan Sheng Optical (GSO). The nature of the beast means the two makers’ telescopes are really very similar. What you want to base your choice on is price and features.

One other thing before we get started? I discovered the 6-inch Dob is becoming an endangered species. Celestron has discontinued their 6-inch Starhopper. Meade’s 6-inch solid tube (and even their 8-inch truss tube) is long gone. SkyWatcher, another Synta brand-name, sells 6es in our price range in other parts of the world, but not in the USA currently. Why should this be? I don’t know, but maybe it is not such a bad thing.

If you absolutely have to keep the numbers at the 500 dollar end instead of the 800 dollar end, consider a six. The 6-inch reflector was the basic telescope of my generation (baby-boom), and it was all many of us ever aspired to. And yet…and yet… Light pollution is worse today, and 8-inch telescopes are far more effective under those conditions. They are also insanely less expensive than they were back in Unk’s day, muchachos.

Orion (Telescope and Binocular Center)

Leaving the too-expensive XTg scopes out of the mix, Orion’s 6 - 8-inch Dobs fall into three families, The XTs, the XTis, and the StarBlasts.

The XT is Orion’s Synta-made basic, no frills Dobsonian. The 8-inch (f/6) is $329.95 and the 6-inch (f/8) is a truly amazing $279.95. What do you get for your money? You get attractive black steel tubes, particle board mounts nicely finished with Formica, good 1.25-inch/2-inch Crayford focusers, and zero-power red-dot “bb gun” style finders. Which you’ll need, since there are no digital setting circles, much less go-to. You get one eyepiece, a 25mm Plössl of OK/good quality. Most of all you get Orion’s top-notch customer service which includes plenty of beginner hand-holding. Oh, and the optics are almost always very good, if not often outstanding.

Downchecks? A red dot finder is insufficient for chasing deep sky objects in light pollution. You’ll want to replace it with an 8x50mm job. Doing so will probably throw off balance despite the presence of a spring that connects the altitude bearings to the rocker box, which is designed to make balance less critical. A weight or two on the nether end of the tube can fix that, of course. The XT’s motions are smooth enough, but azimuth could be a little smoother. All-in-all a great, a wonderful, buy.

The step-up scope, the XTi, which costs $529.95 and $399.95 for the 8 and 6 respectively, adds several upgrades in addition to the Intelliscope digital setting circle computer (which Orion calls a “COL,” “Computerized Object Locater”). The red dot finder is gone, replaced by a real finder scope, a 50mm right-angle-correct-image (RACI) job on the 8-inch and a 30mm RACI on the 6-inch. That’s a little ironic, since the finders are much less necessary on these scopes than on their cheaper sisters thanks to the DSCs. There is a little knob on the front end to help you move the scope, the tube is a pretty bronze-like color, and the rocker box is lighter and more attractive. Most importantly, the spring balance system has been replaced by a more effective tension knob. Oh, and Orion throws in a 10mm Plössl in addition to a 25mm.

Any caveats? Not really. These scopes are even better than the XTs. A beginner, or anybody else, will want to read the manual carefully before assembling the scopes, since the Intelliscope encoders can be a bit dicey to get right. There is a Yahoogroup devoted to the Intelliscope, and the ever-solicitous Orion if you encounter problems, of course.

The final Orion Dob tribe only has one member of interest to us today, a 6-inch. Orion’s StarBlast 4.5 was scaled up to 6-inches not long back, and quite a few newbies are attracted to it due to its low price, $279.95 without Intelliscope, $399.95 with, and small, cute nature. What makes these different from the XTs and XTis? Their focal ratios of f/5 and the resulting wider fields and lower magnifications. Is that a good thing? If you want a compact scope very suited for viewing wide expanses of the sky, it sure is. At f/5, as I mentioned earlier, coma is not too bad and collimation not too touchy.

The problem with the StarBlast 6-inch is not its fast mirror, but its small mount. You will need to put the StarBlast on something—a table, a hefty bar stool, a specially made stand, something—to use it unless your name is “G.I. Joe” or “Barbie.”

Accessories? Both the Intelliscope and the non-computer 6-inch ‘Blasts are furnished with two Plössls, a 25 and a 10, a red dot finder and, like all Orion’s telescopes currently, a copy of the basic edition of the Starry Night software.

Me? I like the StarBlast 6, but I still prefer the full-size f/8 6-inch due to somewhat better performance on the planets at high power and the fact I can just plop the XT on the ground and use it.

Finally, if you really, really don’t want a Dobsonian and believe you can live with 6-inches of (f/5) aperture, Orion sells a Synta scope they call the “Astroview 6,” mounted on a relatively stable EQ-3/CG4 style GEM mount. This pretty telescope (barely) avoids busting our budget at $419.95.

Zhumell

The other major player in the Dobsonian game today is Zhumell, the somewhat odd-sounding brand name of GSO. The Zhumells are offered by a wide array of retailers, from Amazon.com and Telescopes.com (one of the multitudinous websites of the Hayneedle company) to Zhumell’s own website. Are these scopes good? Yes they are good—if you want a non-go-to, non-push-to XT-like scope. BUT there is a little catch…thus far the company and its resellers have not really glommed onto the idea of customer support, with the scopes often not even being furnished with assembly instructions.

The price is certainly reasonable for a Zhumell 8-inch (the 6-inch does not appear to be available right now). It’s a little more expensive than the Orion XT at $379.98, but in some ways it’s nicer. Some people will tell you GSO’s mirrors are better than Synta’s. I’ve never noticed that, but the Zhumell Z-8 does have some upscale features. The side bearing tension system is very well done, the scope is equipped with a 50mm straight-through finder (which I think is easier to use than a RACI), and it comes with two eyepieces, a 9mm Plössl and a 30mm two-inch eyepiece. There’s also a cooling fan for the primary, though you probably won’t need that for an 8-inch telescope unless your conditions are truly bitter. And an “improved” azimuth bearing.

The sticking point with all the Synta Dobs I’ve used is, well, their sticky azimuth motions. The Zhumell cures that by using a lazy susan bearing rather than Teflon pads. Unfortunately, in some amateurs' opinion, that makes the azimuth motion too easy. Oh, well…

Would I choose a Zhumell? If I didn’t want the Intelliscope computer and didn’t need the hand-holding and support Orion offers, I’d be mighty tempted. The telescope offers some significant improvements over the XT in my opinion.

Better still? Telescopes.com currently offers a cool Z-8 bundle. In addition to the scope and its standard accessories you get a Telrad finder-sight, a 16mm 100-degree AFOV eyepiece of Chinese origin with decent optics, a Sky-glow (a little mild for most purposes) light pollution filter, a polarizing filter, and a good beginner’s book, Terrance Dickinson’s Exploring the Night Sky. You could probably assemble better accessories on your own, but probably not for a little over 200 bucks over the price of the scope alone. This package, a little table, a red flashlight, a freeware astro-program, and you could be on your way in right smart style, muchachos. Hell, if I had a spare $599.98, I’d be tempted to take advantage of this steal.

Stargazer Steve

Do you want a Dobsonian that’s a cut above the Orions and Zhumells in some ways? If you don’t mind wielding a hammer, Stargazer Steve may have you covered. Steve, who is based in Canada, will sell you one of his kits, that, when assembled, is both beautiful and functional. Yes, the tube is Sontotube—cardboard—but as a couple of generations of Dob owners have learned, that is durable and is just about perfect for a scope. The rocker boxes of Steve’s scopes are of real plywood, not particle board, putting them light years ahead of the competition.

Only downer? Last I heard, the Stargazer Steve kits are not off the shelf items. Be prepared to wait a while for your kit to make its way to you from Canada. Also be prepared to spend a little more, 379.95 for this 6-inch. What do you get? In addition to a base made from birch plywood, you get a very good Rigel Quik-finder zero power sight and a good Plössl.

Others

While the ranks of inexpensive Dob makers have thinned in recent years, there’s still more than the above big players. There’s old-time optical company Bushnell’s six-inch Dobbie, the “Ares,” which is certainly cheap at $224.99. For which price you make out fairly well. The scope includes a couple of imported Plössls and a 30mm finder scope.

Who makes this telescope for Bushnell (who does not make any of the telescopes they sell and hasn’t in a long time)? Hard to say. It looks like a Synta, but I am not sure. Would I buy one? Not without knowing for sure who made it and trying one first. As most veteran amateurs will tell you, “Bushnell” has been synonymous with “crap” for a long time when it comes to telescopes. This Dob may be different, but I do not know that. The fact that the company's own website sports an image of this little scope pointed at the center of the Earth does not exactly inspire confidence in their astronomical expertise.

There is another frequently seen brand of Dobbie, “Galileo,” but, as is the case with the Bushnell, I know nothing much about these Dobsonians—except they seem to be a favorite of internet non-astronomy merchants, like Amazon.com and Overstock.com. What kind of a buy might they be? At over 350 bucks, their 8-inch is competing directly with Zhumell and Orion. These are attractive telescopes, but I’d need more information before trying one. Their advertisements’ information that the 25mm eyepiece shipped with the scope is of the “Astroscopic” design is enough to give this old boy pause.

Finally, there is Discovery Telescopes, who are more well known for their larger Dobs, including a line of inexpensive truss tube rigs. They do, however, still offer one Dobsonian in our range, the 8-inch PDHQ. You do get a nice plywood base, but otherwise the telescope and its accessories look pretty pedestrian to me. The kicker? This pup will set you back a cool $999 smacker-roonie-ohs.

Worth it? While it is much more expensive than the competition, Discovery scopes have often had a reputation for being better than the run-of-the-mill Chinese imports. “Often,” but not “always.” The company also has a reputation for taking a long, long time to deliver telescopes and not being very willing to communicate with the customers it keeps waiting.

Next up was supposed to be a survey of the accessories you will need. Eyepieces, charts, chairs, computer programs, yadda-yadda-yadda. But as you can see we are well and truly out of time/space for this Sunday, so that will just have to wait for a part two. Which will appear week-after-next—if the weather cooperated last night.

Next Time: Once more unto the breach, dear friends—with the Herschels.

Comments:
Nice review. About two years ago at age 10, my Matthew worked odd jobs around the neighborhood to buy himself the 6" Star Blast. Not only is it his favorite scope to take to Chiefland, it was the scope he used to complete his Astro League Sky Puppy Certificate!

Looking forward to part 2....
 
I would definitely not recommend Discovery. They still haven't improved the customer service aspect of their business after all of these years and bad press, and they are still completely incapable of providing honest delivery estimates. When you're told two weeks, it really means at least four months, but they'll lie to you and tell you "next week" every time you ask.

I hate to call them out, but I have to call it as I have personally seen it.
 
I had to laugh when I saw the picture you included of that Bushnell Dob, as you say, pointed at the center of the Earth. I once saw someone describe that as "Department Store Display Configuration".

My first scope is a Hardin Optical DSH-8, which is very similar to the Zhumell of today. About a month after I got it, Hardin went out the astronomy business - Not that it mattered. It was so good, I didn't need support.

What's nice about an 8-inch Dob such as mine, is that you can eventually take it off the alt-az mount, fit it with rings/dovetail, and put it on a GEM, which is precisely what I did. My venerable DSH-8 now resides on my CGEM mount, controlled by nexremote on my netbook computer, with AstroPlanner controlling the go-to's.
 
Great Blog look forward to spending some more time reading it. :) Help needed for y2k chip for Celestron U2K telescope. enjoy, shane@cbm8bit.com
 
Unbelievably useful Blog! I really love it! Wow!
Just wanted to say thank you so much, for all of this great/useful info. I was just reading the top of the page today (Sunday Feb.27th Post), and it's great! I've been feeling just like that!

Well, here's an old Blog of mine:
http://urbanastronomy.blogspot.com/

Thanks again,
Al
 
Duh! I just realized that Uncle Rod is actually the Author of my new favorite book! - 'The Urban Astronomer's Guide: A Walking Tour of the Cosmos for City Sky Watchers (Patrick Moore's Practical Astronomy Series)' I just finished writing a short review of it on my Blog. Wow! That explains why I love this Blog so much : ) That is soo funny!

Clear, dark skies to all,
-Al
 
Yep...there is only one of me...

"Thank God," Miss Dorothy says! LOL!
 
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