Ode to the Small Scope August 23, 2009Posted by Treehopper in astronomy, equipment, opinion.
Tags: astronomy, small aperture, telescope
Maybe I’m just a sucker for the underdog. Maybe I’ve never quite gotten over that tendency to be an underachiever. Or maybe it’s just the allure of not using the biggest and best equipment and still enjoying my astronomy habit. But I’m usually in the vocal minority of folks who routinely defend and champion the smaller aperture telescopes.
I’ve seen it happen time and time again. A neophyte would-be astronomer comes asking one of the very first questions a newbie always asks when in the company of more learned folk. “How do I select a new telescope?” And it seems as though as sure as night follows day the majority will rise up chanting the near-universal mantra, “Aperture is king! Buy the biggest thing you can afford!” And more often than not, what they mean by this is, “Get a Dobsonian reflector! Dobs rule! I wouldn’t let my ugliest, smelliest dog sit on anything less than a 8-inch Dob!”
“I remind myself that the likes of Galileo, Newton, or Messier didn’t have even an 8″ Dob to accomplish the deeds for which they are so highly regarded and fondly remembered these centuries hence”
There’s some merit to this, to be perfectly honest. In truth, the Dob is about the least expensive option per inch of aperture to be found. You don’t have to monkey with temperamental mounts like the perennial German Equatorial Mount (or GEM), you’re not dead in the water when your GoTo goes flakey or your batteries die, and you do get quite a lot of light gathering relative to the monetary investment. These are the upsides to the Dob that I willingly accede to.
However, what these devotees to the almighty lawn cannon often don’t take into account are other criteria for selecting an astronomical instrument, particularly with the new student in mind. I’ll use my own experience as an example. When I first was seriously bitten by the astronomy bug, my friend and mentor Jim didn’t recommend a telescope right up front. For the first six months or so, I didn’t so much as even look through an eyepiece. Instead, I learned the night skies with my unassisted eyes, and every once in a while would augment them with a cheap drugstore pair of 7×35 binoculars I got as a Christmas gift as a kid. When I finally did look through a telescope, it wasn’t some grandiose light bucket. Instead, it was through a home-brew refractor.
The objective was an oddball…around 90mm edge to edge, with a little “clam-shell” divot about the size of my pinky fingernail on the crown side. We blacked out the defect, mounted it in a 4″ blue sonotube with a cannibalized rack-and-pinion .965 focuser on the business end. We did what we could to help it along. We coated the inside of the tube with flat black spray paint, I got my hands on a converter diagonal to go from the smaller .965″ to 1.25″, and made a light/dew shield out of a modified coffee can (spray painted inside and out to match the rest of the scope.)
The mount was even more humble, if you can imagine it. It sat on a square plywood base with a threaded metal plumbing socket screwed into the center. A collection of short metal tubes and elbows created a slingshot-shaped “Y” mount, and two 1/4″ carriage bolts with washers out the wazoo attached the OTA to the slingshot. Two over-sized wingnuts controlled the tension on the altitude plane. On the bottom of the square mount base were screwed-and-glued three small blocks of wood with holes drilled in the centers. They were spaced about 120° equidistant to each other. Bolted to each of these blocks was a leg crafted out of discarded wooden crutches! That’s right, crutches! The span that formed the upper part that normally would go under your arm was removed, as were the “handles” in the middles, and then they were squeezed together at the top and bolted through the blocks. About midway down the length of each leg was an eye-bolt that was screwed into the thickest part of the leg; these would accept a thin metal chain spreader to keep the legs from flying akimbo unexpectedly. All tolled, it cost about $20 at the local hardware store and an afternoon of labor to put it all together. After thinking long and hard on a suitable name for the poor thing, we hit upon “Hobble” as being singularly appropriate considering it’s appearance and construction. It was among the most hideous grotesqueries to ever grace the star party circuit.
And I wish I had it today! It may have been uglier than an inbred coon-dog, but that little sucker could really see the skies!
I’ve since then experienced many such “humble” instruments. Some of them are refugees from weekend yard sales and church bazaars. They’re usually pretty scuffed up, some have parts missing or are in some state of outright disrepair. Almost without exception, none of them has been so far gone that they haven’t benefited from a little time and TLC. And once they’ve had a fresh coat of paint and some adaptation to make them a little more usable, they all found homes with very grateful new owners. You couldn’t convince one of these people, whether they were 9 or 79, that you hadn’t just handed them the keys to Palomar. Some were shocked, others laughed nervously and yet others shed tears of gratitude, but not one of them complained that it wasn’t big enough to see anything with!
And this is precisely my point! Some times we’re so eager to help newbies spend their money the “right” way, that we may have forgotten (or perhaps, some never actually experienced) what it’s like to view the cosmos through a humble little scope. I stand among the fringe of others who didn’t have the benefit of the enormous optics often scattered afield like massive dandelions at large star parties. I remind myself that the likes of Messrs. Galileo, Newton, or Messier didn’t have even an 8″ Dob to accomplish the deeds for which they are so highly regarded and fondly remembered these centuries hence.
At some point, I’ll post my take on the criteria I use for advising new would-be observers on which instrument suits them the best. Suffice it now to say, I don’t always subscribe to the “Aperture is king” party line. My battle-cry is more along the lines of, “Get the scope that will most adequately perform the purposes for which you got it.” Certainly, aperture should be one of those criteria. But we can’t overlook other, equally important topics such as portability, functionality, ease-of-use, and of course the all-important “fun factor.” If you haven’t learned yet how to actually have fun with a 60mm or 80mm refractor, or 4.5″ “newt”, then perhaps you’ve deprived yourself from one of the real joys in this hobby. Seeing the skies the way some of the “giants” in the last 400 years have seen them. Now THAT’S fun!