Sunday, October 23, 2011
The Christmas Telescope
We’re approaching the end of October, muchachos, which now marks the beginning of the Christmas season. Which for you and me is more than just ho-ho-ho and mistletoe and presents to pretty girls. It is also the coming of Christmas telescope season. Some of your friends and family will get one; maybe this Christmas. When they do, they will be full of questions, questions they will direct your way. You are the TELESCOPE GURU, after all.
Need I explain what I mean by “Christmas telescope”? Prob’ly not. I’m guessing every amateur knows what I am talking about. I don’t just mean “a telescope you get for Christmas,” but that most maligned member of the telescope tribe, the department store scope (DSS). One of those shiny 60mm refractors you admired in the big store downtown way back when, one bearing a logo that read “Tasco” or “Jason” or “Sears” or “J.C. Penney.” The DSS is still alive and kicking, if slightly bruised and battered and now mostly found in Wal-Mart (locally).
Whoever makes ‘em, Department Store Scopes share some common characteristics: they are relatively inexpensive, they are imported, and, most of all, they are sold by anyone but astronomy dealers (usually). There have always been Newtonian reflectors in their ranks, often 4.5-inch f/8 jobs, and there have been a few 3-inch and larger refractors, but most DSSes have been 60mm refractors. Many of the early ones, especially the more expensive models, were at focal ratios of f/15 - f/16, while those from the 80s and on tend to be considerably faster, closer to f/10.
DSS Mounts have varied over the years, but until recently the best of the breed were on EQ-2 sized German equatorials. On the lower end of the price scale there were small fork alt-azimuth mounts—often used with sub 60-mm refractors and sub 4-inch reflectors. Over the last five years or so, most of the GEMs have disappeared, and the majority of scopes are now on alt-azimuth mounts, often single-arm forks equipped with electronics like (rudimentary) digital setting circles.
What besides a scope and a mount was in that mind-blowing, psychedelic 60s box? In the hey-day of the DSS, the accessories could be lavish, if quality was sacrificed for quantity. Most scopes shipped with two or three eyepieces, a Barlow, a Sun projection screen (or a dangerous solar filter), sometimes there was an illuminator for the tripod accessory tray, and most had a finder scope of some kind—Unk’s 3-inch Tasco Newt came with a sorry looking peep sight. It’s about the same today. The bad, old Sun filters are gone, but there is lots of other junk in the box to play with.
Most of the stories about dreadful DSS accessories concern how terrible their eyepieces are. That’s true, though usually the longest focal length ones have been at least bearable, and through the early 80s the more expensive DSSes (like the best Sears refractors) had pretty good .965 oculars. The Barlow lenses? Fuhgeddabout it. Those plastic-barreled horrors have never been any good. Their sole purpose? To get your 2.4-inch scope up to the 600x trumpeted on the box.
A close second in badness to eyepieces is the DSS finder. Even forty years ago, finder scopes were way too small. The best you could expect would be a 23 - 25mm job, too small even for a 60-mm scope. As the years went on, finders became ever smaller, eventually devolving into pitiful things with tiny single-element objectives fitted with masks to aperture them down even more (to keep them from turning into a kaleidoscopes). Surprisingly, back in the 60s – 70s the Tascos and Jasons weren’t the only offenders. Their very expensive cousin, the Unitron 60mm, had a way-too-small finder too.
If DSSes old and new have had a single strength, it has been their optics. You may have heard folks say replacing the scopes’ eyepieces improves performance a lot. That is true. Most refractor objectives were and are surprisingly good, showing very little color at their typically slow focal ratios. The mirrors of the reflectors have always been spherical, but they have often been very good spheres and perform well at the accustomed f/8 focal ratio. A couple of new eyepieces, a decent finder (or a zero-power sight), and a 1960s through 1980s DSS may amaze. You-all may have noticed I keep mentioning those three decades as the salad days of the Department Store Scope. What’s up with that?
There had been small telescopes for sale to the public long before the 1960s, but they were usually insanely expensive. They were most assuredly not mass-market items. That changed post World War II for three reasons: the Baby Boom generation of kids was ready to be entertained and educated, the space race was on and Mom and Pop wanted their kids to learn science, and Japan was hell-bent on developing an optical industry.
The first telescopes to be widely marketed to children were not from Japan, but from the U.S. of A., from A.C. Gilbert. Alfred Gilbert’s company made things that could be described as toys, I reckon, but they were toys of a different sort, toys made, like Gilbert’s famous chemistry sets, to educate sprouts about the ways of the scientist. With Sputnik soaring overhead, Mr. Gilbert decided to bring astronomy as well as chemistry to the children of America.
The Gilbert 2-inch Newtonian reflector turned a lot of us Boomers on to astronomy. If there had not been an A.C. Gilbert telescope, Stephanie’s telescope, I suspect it would have taken considerably longer for me to find my way into astronomy. These simple instruments and similar ones from Skilcraft and others showed that kids (and maybe their parents) were ready for astronomy. People noticed that, including businessman George Rosenfield, the owner of the Tanross Supply Company of Miami, Florida.
|The beautiful 20TE.|
The secret to this goodness was that George bought the products of renowned (today) Japanese companies like Royal Optical and Goto and Towa. The king of the hill was Tasco’s magnificent 4-inch 20TE “Observatory” refractor and the only slightly less magnificent 10TE. You were unlikely to find in your town’s department store and unless you were well-heeled you'd have lots of trouble paying for either.
Tasco’s emphasis was on small apertures, 4.5-inch reflectors and smaller and 3-inch (only a few of those) refractors and smaller. These scopes were relatively inexpensive even compared to the scopes of the more budget oriented American telescope companies like Edmund and Criterion. AND...you could trot down to the corner Sears or Monkey Wards and get one and be observing that very night. Good luck with that if you chose an Edmund Space Conqueror or a Criterion Dynascope.
Tasco telescopes started a lot of young folk on the road to an amateur (or professional) astronomy career. Hell, I was mightily impressed by the 4.5-inch Tasco Newtonian I bought in an Air Force Base Exchange in the mid 1970s. I had to admit it was well made and performed well, even if it was not perfect (never did like them little .965 eyepieces), and was quite a value. Tasco continued to thrive, importing plenty of good telescopes for over twenty years. What happened after twenty years? H-A-L-L-E-Y.
That changed with the coming of Halley’s Comet and the growth of the Taiwanese optical industry. As the 80s began, anyone selling telescopes realized the comet was a potential gold mine. Everybody would want a scope, and the fact that you could now buy telescopes from Taiwan meant you could get a lot of telescopes and you could get them cheaply. That’s what all the importers began doing, including Tasco.
The early to mid 80s were a golden age for the DSS. At first, quality remained reasonably high, and the flourishing of big box jewelry stores like Service Merchandise gave Tasco and Jason the perfect place to peddle their wares. No doubt these two sold a lot of scopes during the comet’s run, but when the unimpressive Halley passed, the spigot quickly shut off.
Faced with ever more need to economize, “Chinese” became the norm for the importers, and quality began to decline precipitously. Frankly, this had begun during Halley-mania, but got progressively worse afterward. It was noticeably worse at Tasco after Mr. Rosenfield’s retirement and the sale of his company, and quickly went beyond ever cheaper accessories to the plastification of the telescopes. So it was with all the DSS importers. Everything that could be plastic instead of metal was plastic. If a part was still metal, it was the cheapest casting possible.
Where are we today? Tasco is still around, though they have been bought and sold a couple of times. I haven’t seen a Jason in a long time, but they are also apparently alive. J.C. Penney and Sears? You can still buy telescopes from Sears, though they are usually only available online at Sears.com. Last time I checked, J.C. Penney sold no telescopes of any kind, online or offline. The DSSes Sears sells are no longer branded with their name, and are an assortment of the good, the bad, and the ugly from Bushnell, Tasco, Celestron, and Meade.
Bushnell, by the way, ain’t the Bushnell of old. Like Tasco, their name has been bought and sold several times. They, along with Jason and Tasco, are now all the property of an equity firm, “Mid Ocean Partners.” Which doesn’t really mean pea-turkey, since all the brands are and always have been nothing more than badges pasted on imported telescopes. The key to the goodness or badness of the scopes is what these companies choose to import at any given time.
Celestron and Meade, and especially Meade with its “DS” series (I wonder what those letters stand for "deep space" or maybe something else?), have been major players in the department store scope game for almost two decades. Over the last four or five years I’ve seen fewer of their DSS models sold locally, though. Maybe because of economic conditions, and maybe because the “science stores” like Discovery Channel Store, which were a prime outlet for lower level Ms and Cs, have all gone out of business. Meade and Celestron DSS range scopes are still common at online retailers, though.
There is, I was surprised to notice, one new player in the DSS game. Ioptron, the Minitower/Cube mount folks, are not just peddling Cubes paired with minimalist OTAs on eBay; they are selling genuine Department Store Scopes, 60mm GEM-mounted refractors in your choice of red or blue paintjobs, in various online venues. How do they look? Remarkably like the GEM refractors of twenty-five years ago.
Ioptron’s entering the Department Store Scope bidness is about the only news I have to relate this year. Tasco and Bushnell are sputtering along, but seem to be offering fewer scopes this season. The quality of these scopes, while not at an all time low, is nothing to write home about, either. There is still way too much plastic and too much of the production budget goes into modern gimcracks like digital setting circles and go-to that rarely work—even poorly. Optically, not much has changed. The objectives and mirrors are still mostly OK; it is the everything-else that sucks if anything sucks.
If there’s bad news about DSSes this Christmas, it’s that their makers and importers are continuing their love affair with short tube reflectors, long focal length Newtonians with short tubes. What they do to achieve that is furnish the scopes with fast f/4 mirrors and install “corrective lenses” in the focusers. Problem is that these fast mirrors are still spherical and the corrective lenses are just cheap and crappy Barlows. The combination, not surprisingly, results in absolutely horrible images.
Want a really bad scope? Welcome to the wonderful world of eBay astronomy. If there are heirs to the worst of the 90s crew, you can find them on the ‘Bay. A tip-off as to their badness is that what is often most prominently advertised is not their design or aperture, but their tube color: “red telescope,” “blue telescope,” etc. Not only are they usually worse than the worst of the Wally World bunch, you will pay considerably more for them after ponying-up outrageous shipping fees. Want the straight poop? Read the Cloudy Nights review my friend Jon Isaacs wrote about a “Baytronix” short tube reflector.
With the depression (I ain’t afraid to say it) still on, the market for DSS telescopes has been much reduced the last couple of years. There were no Christmas scopes at our Wal-Mart last year, and I have not seen any there this year—yet. So far, the DSSes I have seen have been in drugstores and sporting goods stores and have been distinctly on the low end of the price/quality scale. I saw minimalist 60mm refractors in the Chiefland, Florida CVS Drugs last Christmas, and discovered a brace of ‘em in the Possum Swamp CVS this past weekend. I also spotted several little 50 - 60mm fellers prominently displayed in the front of the local Academy Sporting Goods. But that has been about it.
Wherever they come from and in whatever numbers, there will be DSSes this year. Like the Whos’ Christmas, they will come ANYWAY. And you will be called upon to help with them. While there’s little that can be done to improve the lowest of the low, the 20 dollar 50mm scopes, most DSSes, e’en today’s somewhat debased breed, can be helped.
What do you say when a novice brings you one? What you do NOT say is, “Well, that’s junk. Here’s an Orion catalog; I’ll help you pick a real telescope.” It may be appropriate to dispense that catalog when (and if) it is time for Jane Novice to upgrade, but, for now, hold your peace. How would you like it if someone pronounced your beloved scope “junk”? Joe Novice will feel exactly the same. Maybe even moreso. That clumsy telescope may have been wished for and dreamed about for weeks and weeks.
What you do say when presented with even the crummiest DSS is “Great! You’ll have a lot of fun with it. I can show you how to use it, and we can tune it up a little to make it easier to use.” And that is the truth. When I was a kid, an humble Gilbert, which could show the craters of the Moon and the rings of Saturn, if only dimly, would have been incredibly wonderful to me. And even the cheapest Wal-Mart refugee of today can do those things better than that 60mm cardboard tube Newtonian could.
To paraphrase one of my heroes, Linus van Pelt, “It's not a bad telescope at all, really. Maybe it just needs a little love.” What do most DSSes need in addition to love? Glad you asked…
Oculars are the place to begin. While the longer focal length eyepieces shipped with a DSS can be workable, they are certainly not optimum, and the shorter f/l ones generally have nearly zero eye relief, tiny eye lenses, and poor optics. The DSS makers are still sticking to the tried and true of their trade: Kellners if you are lucky, Huygenians if you are not. There is one light in the forest, though. Many DSSes now have 1.25-inch focusers. With good .965 oculars a rarity, you can now upgrade to 1.25-inch eyepieces without resort to replacement focusers or hybrid diagonals.
What to replace ‘em with? Ideally, with a couple of the cheap Plossls you’ve got squirreled away in the back of a drawer. How many? Start Jane off with two, maybe a 25mm and a 12mm. If you’re doing your job correctly, Jane and Joe Novice should understand they don’t need high power and why. If they seem doubtful, crank it up with the plastic Barlow and 4mm eyepiece that came with the scope. What if you don’t have any spare eyepieces to give out? Chinese Plossls are cheap and good. My fave loss leaders are Gary Hand’s GTO Plossls, which can be had for less than 30 bucks a pop. You can likely undercut that at a swap table at a star party or on the Astromart.
If the focuser has so much slop and shift it’s impossible to get the image sharp and keep it centered, you need to fix it. That can often be as simple as tweaking adjustment screws. Do be careful, since most DSS focuser bodies are plastic. At worst, you might have to install some shims. If not sure what to do, enquire with an ATM buddy.
Right after poor eyepieces, the number one offense of DSSes is that their mounts are too shaky. Let’s fix that starting with the tripod. Once upon a time, Department Store Scopes came with wooden tripods that were usually OK. Today, extruded aluminum is the norm. When properly done, aluminum tripods can be fine, but they are, natch, rarely done properly in the DSS. What to do? Start out by tightening all the hardware, especially anything associated with the accessory tray. Don’t strip any bolts and be careful to leave anything loose that needs to be loose for proper operation. One way to make a huge improvement is to replace the accessory tray with a triangular piece of plywood firmly attached to the legs. Downside is that the tripod will no longer be collapsible—but the improvement will be worth it.
Often just tightening bolts provides a real steadiness increase, but if not you can try filling the legs of an extruded aluminum tripod with sand or some other material. But that is a pain and usually doesn’t make much difference. What will make a difference is vibration suppression pads—like those Celestron and Orion sell. With one under each tripod foot, the scope will be much steadier. Unfortunately, a set is 50 dollars or more, but you can gain at least some of the same benefits using things like hockey pucks or bathtub drain stoppers under the tripod legs. If the tripod is tall enough for your apprentice astronomer to use comfortably with the legs retracted, you might instruct her to always observe without extending the legs, which will always make the scope steadier.
Whether GEM or alt-az, make sure all hardware is tight and that the head is firmly attached to the tripod. What else? Depending on the size/sturdiness of the mount, fill either a gallon or quart milk jug with some water and suspend it from the bottom of the mount head. That will do a lot to reduce vibration. If slow motions are too tight or too loose, adjust gear mesh so they are easy, but without too much backlash. You won’t get it perfect; “good enough” is good enough.
How about electronics? If you can get DSCs or go-to working reasonably well and can show your novice how to do the same, OK. If not, tell your buddy to forget about that stuff for now. Instead of agonizing over a gadget that will, at best, only get “kinda close” to objects, encourage your Padawan Learner to use the scope manually.
The OTA (tube)
If the telescope is a Newtonian, collimate it and be SURE to show the owner exactly how to do that, too. Unless the telescope is one of the nasty little short tube reflectors (which are often impossible to collimate), collimation is not difficult. Mirror alignment is not too critical at f/8, but every little bit helps.
Is the scope a refractor? Check its collimation by observing the diffraction rings of a slightly out of focus star. A lens scope will often be OK, but not always. If not, collimate it. Unfortunately, the objective cells on most DSS refractors do not include collimation adjustments, but you can still collimate. Loosen the screws that hold the tailpiece/focuser to the tube and move as needed to make the diffraction rings concentric, retightening the screws when done. Usually the screw holes in the tube will be large enough to allow sufficient tweaking.
Finally, put a decent finder on the scope. My choice for beginners is a zero power sight. If the tube is too small to accommodate a Telrad (the best), a Rigel Quickfinder or one of the red-dot sights like those sold by Orion is almost as good. Having a right-side-up, non-magnified view will make aiming so much easier for your “client.”
What else? The usual things. Set your Padawan up with a set of star charts—maybe the computer programs Cartes du Ciel and Stellarium—and a planisphere and show her/him how to find good stuff. Make sure the idea of using a red light at the scope is understood, and give or make your apprentice one. Also give Joe or Jane a good beginner’s book, or at least the title of a good one. Caution about cleaning optics (in other words, DON’T), and then…and then… You might give the novice a check ride under the stars, but mostly it is time to let your little bird fly.
Don’t be discouraged if it turns out your novice’s interest in astronomy was a fleeting thing. When it comes to being an astronomer, many are called but few are chosen. It’s a special type of experience, and one that requires real work. If you did your job right, though, it’s possible the owner of that Christmas scope will be coming to you next year for advice about a REAL TELESCOPE.
Even if that does not happen, many of these much-maligned telescopes have long and productive lives. They may not get used every night or even once a month, but they do get used when their owners suddenly have the yen for Moon craters or Saturn’s rings or Jupiter’s Moons again. I am tempted to say there is no such thing as a bad telescope; even the most humble and silliest can open a young person’s eyes for the first time. I don’t grumble about the little scopes in the gaudy boxes at the front of Wal-Mart anymore. I welcome them every Christmas.
Excellent article Uncle Rod. Not a sidewalk astronomy event goes by without a novice Joe asking Matthew and I the very same questions....(I usually refer them to Matthew. He provides much better 'tech support' than I do).Post a Comment
Just loaded up the van for our trip to C.A.V. Look forward to next weeks blog.
Just loaded up the van for our trip to C.A.V. Look forward to next weeks blog.