Friday, March 30, 2007
Sky Adventures with my A.C. Gilbert
|Jellyorum likes the new scope!|
“A watched pot never boils.”
“Having is never as good as wanting.”
English, especially American English, is littered with aphorisms about the beauties of delayed gratification—as befits our Puritan heritage, I suppose. But, dang, I finally decided my gratification had been delayed way too long, 44 years to be exact, and that I was going to do something about it.
What is your silly old Uncle talking about now? My long-unrequited love affair with A.C. Gilbert telescopes.
If you’ve read my “astro-bio,” you know all about Stephanie’s Telescope. If you haven’t, well, to make a long story short, What got me started on the astronomy road way back in 1963 was a classmate’s show-and-tell presentation of her brand-new and wonderful, A.C. Gilbert reflector.
Never heard of A.C. Gilbert? If you’re a sprout, I ain’t surprised. That wonderful company has been gone these 40 years. The memory of it is still green in the minds of those of us who lived through a 50s – 60s childhood, however. Well, not all of us, maybe. Back then, you probably had to be a boy-type kid to appreciate the products Alfred Gilbert’s “toy” company sold. “Toy” in quotes because that really doesn't seem adequate to describe the man’s products. They were so much more than that.
Chemistry sets. Electronics kets. Erector sets. Microscopes. Even telescopes. Gilbert sold a few things that could be described as “toys”—they offered magic tricks and building blocks. But mostly what they sold was dreams. Or maybe tools. Simple tools designed to give a little person the idea that those dreams of high-flying rocket ships and world-changing scientific breakthroughs might be made real some day.
“Simple” was the operative word for describing Gilbert’s plastic and cardboard creations, but the kids who lived in that simpler and more naïve (maybe) time didn’t care. For us, a few test tubes and little bottles of semi-household chemicals (BORAX! TANNIC ACID!), were the beginning of a lifetime interest in—and for some of us, a career in—science or engineering.
Chemistry sets and erector sets were Gilbert’s main and most remembered creations, but, with the space age coming in, he didn't ignore astronomy. By the end of the 1950s, the company was selling telescopes too; little 60mm f/12 reflectors (never knew there were sub-3-inch Newtonians, did you?). Me? I had became obsessed with Gilbert’s telescope. As I say in my bio, I HAD to have one.
Alas, ‘twas not to be. Gilbert didn’t exactly give scopes away, not as Mama and Daddy reckoned such things, and with the family settled into in its usual after-Christmas semi-poverty condition, there’s wasn't a dog's chance in hell of 10-year-old me hitching a ride on the A.C. Gilbert wonder wagon any time soon. Actually, I did get a scope a couple of years after Stephanie's show and tell presentation, but it was not a Gilbert. In fact I never owned an A.C. Gilbert scope or even put my hands on one again for over 40 years.
Which didn't really seem to be such a bad thing at the time. I eventually progressed from the 3-inch Tasco Newtonian Daddy rescued from a pawn shop, moving on, by means of extensive summer lawn-mowing, to a 4.25-inch Edmund Scientific Palomar Junior. From there, the sky was literally the limit as I moved on to Celestron SCTs, leaving childhood and the A.C. Gilbert in the past where I thought they belonged.
I never did completely forget Stephanie's Telescope, though, or the many days and nights I spent wistfully dreaming of the wonders one like it might show me: the mountains and craters of the moon, the rings of Saturn, exploding suns!
44 years later, it’s the age of eBay. If anything's made the Internet appealing to the general populace it’s eBay. Anyhoo, one lovely Chaos Manor South afternoon I was browsing that strange and wondrous site, searching under “telescopes” as I sometimes do, and to my amazement found that I could actually buy a Gilbert telescope.
Should I? Spend what would probably be an exorbitant sum for an ancient child’s toy? Sure I should. Despite all the great equipment I’ve owned and used over the years, something’s always seemed to be missing. What was missing, I knew deep down, was this little cardboard-tubed dream-machine. That being the case I screwed my courage to the stickin' place and ponied-up (too much) for an A.C. Gilbert wonder-scope.
When the box arrived, I was both pleased and appalled. Pleased that the scope was mostly complete. All that appeared to be missing was the lower tube end ring. The beautiful little booklets were there. The cool solar viewer attachment was in the zippered scope case (which is still as impressive now as then, even if it is made of pressed cardboard). Unfortunately, though, the years had not been kind to the primary mirror.
Maybe 20% of the coating was left. On the one hand, I was P.O.ed ("put-out;" this is a family-friendly blog, y'all) that the seller had not mentioned this fact. On the other hand, I supposed the people who sell these things look upon them as “collectible toys,” not something to actually be used. Sigh. I didn’t bother to try the little thing beyond a look at a distant telephone pole, which yielded a dim and blurry image.
Over the following months, I did not forget my quest for Stephanie's Telescope, however. I could have had somebody recoat the little primary, but that seemed overkill and somehow untrue to the spirit of the thing. I figured I would eventually turn up another A.C., one with a better mirror, and that I might be able to combine two scopes into one workable one (in addition to a missing end ring, my Gilbert’s case was on its last legs).
Some time later, I found a Gilbert sans tripod for less than 20 smackers on eBay. I enquired with the seller as to the condition of the mirror, and was informed that it looked “pretty good.” When it arrived, I removed the primary, which, after a gentle cleaning, was indeed in pretty good—if hardly pristine—shape, and put it in the OTA of the original scope (which tube was in slightly better condition). I also transferred an end ring and moved the whole thing to the better case.
The mirror is, believe it or not, mounted in a simple but “real” cell, which is collimated with three bolt/nut/spring arrangements just like a big boy’s scope. I didn’t mark the primary center, just collimated by eye until everything looked good enough. The long focal length of the A.C. makes up for a wealth of optical sins.
The first step, of course, was assembly, which was as simple as could be. Attach three small black extruded aluminum tripod legs to the “mount” base with thumbscrews, place scope on minimalist mount, and you’re done. The mounting itself is a very simple “pillar and claw” variation that consists of a bracket that’s squeezed together with a bolt on the scope side and a metal ball on a shaft on the mount side for this bracket to swivel on. Snap bracket onto ball, tighten thumbscrew until the OTA’s alt-az motion is just right, and you’re done.
Next? Trot scope into Chaos Manor South backyard. Plunk it down in a spot where the Moon would be in view. Wait one last half hour at the tail end of 44 long, long years. What would I see? The first challenge was getting my eye to the eyepiece so I could see anything.
As is obvious in the photo, this is a dramatically kid-sized scope (though it’s a Big Gun for my cat, Jellyorum, who was very interested and happy to pose). The tripod places the eyepiece no more than three-and-a-half feet off the ground most of the time. I could have found a table or stool to elevate the little thing, but with a First Quarter Moon high overhead, the eyepiece was high enough so that I could contort my minimally flexible body enough to take a peek.
What did I expect? Not much. Beyond any doubts about the quality of the primary, there was the eyepiece question. The “eyepiece”—and I use that term loosely—for these scopes was a non removable two-element Ramsden (if you don’t know what that is, don’t ask; you don’t want to know) in the all-plastic analog of a .965-inch rack and pinion focuser.
Surprise.When I got the Moon in view with the aid of the non-magnifying and over-long sight tube that substitutes for a finder, the little scope was able to present a respectable image. The Moon was a mite hazy but that was probably attributable to a dirty secondary (I’d cleaned the primary, but forgot to take a good look at the secondary), but was surprisingly sharp, with plenty of detail on view. The great Crater Copernicus showed off some floor detail and wall terracing. Certainly it would have thrilled me as a child. Darned sure would have.
The image probably would have been even better if I’d been able to use a little less magnification than the 80x supplied by the Ramsden. While I’ve heard that some of the Gilberts had a semi-interchangeable eyepiece system where you switched out the eye lens but not the field lens (!), there was only a single eyepiece in the box with the first scope I received. The second example had a simpler non-rack-and-pinion focuser equipped with an eyepiece that was even less removable.
What else? The Moon was wonderful, and would have been immensely more wonderful way back when, but I’d have been even more anxious to see Saturn. Of that I have no doubt. Luckily, the ringed wonder was only a few degrees from Luna, so I didn’t have to contort my body to use the devilish little “finder” again.
And there he was. Not a very good image as we judge such things in these latter days, but good enough. The rings were visible, and, when I held my mouth just right, I could make out Titan. Frankly, in the eyes of a child the sixth planet would have been fantastically beautiful. No, I couldn’t see Cassini’s Division, and, no, no disk banding was visible. The mount, such as it was, was awfully shaky, too, and no matter how I adjusted the wing nut to change tension, backlash was a big problem. Focusing? Don’t ask.
None of that mattered. The boy who, I found to my surprise, had suddenly displaced the middle-aged man at the eyepiece, was riveted. I could actually see RINGS. That tiny firefly of a speck beside the planet? That wasn’t just an anonymous star, it was TITAN. The same mysterious moon I’d visited in Alan E. Nourse’s Trouble on Titan. It was there; I was seeing it. I was seeing it in my own backyard with my own eyes; with my own telescope.
Who can ask for more than that, then or now?
Next Time: Is Anybody Surprised?..
Tuesday, March 20, 2007
Everything Old is New Again: CdC 3.0
What’s everybody’s favorite freeware planetarium program? Patrick Chevalley’s Cartes du Ciel, of course. OK, I know lots of you also like that other shareware masterpiece, Hallo Northern Sky, and that new upstart, Stellarium, but CdC is still ahead in the race for the hearts and minds of amateur astronomers.
It’s easy to see why Cartes is so well-liked. It’s not just that it’s free, it’s capable and useful, containing some features that even the most expensive astronomy applications don’t boast. The ability, for example, not just to download Digitized Sky Survey Charts—almost any astroware worth its salt is Internet aware these days—but to superimpose these images on your charts. The program also boasts many and huge catalogs, runs fairly zippily on run-of-the-mill modern computers, and is—did I mention this already?—free. It’s so good I once chided Patrick for not trying to make at least a little money off it. His reply? “Rod, I’d rather see amateurs spend their money for a new eyepiece than for astronomy software.”
Yeah, CdC is great, but nothing is forever. There’s no denying Cartes, decked out in its Windows 98 finery, is starting to look a little over-the-hill. Looks ain’t everything, and you will find CdC will still do just about anything any of the most expensive and modern programs will do, but there issues. Cartes grew like Topsy from its modest initial releases into a full-featured program. As is often the case with one-man (or nearly one man) software writing operations, the code became a little less than “optimum” over the years as the features were piled-on, and that means CdC runs a little less well than it could on today’s fast machines. Then there is the fact that CdC only runs on Windows PCs. With Apple making a strong comeback and Linux installed on quite a few observatory computers, it seemed a shame Cartes was only available for the Windows machines.
So, when would Patrick grace us with a new version? If you’ve been visiting the Cartes website at least occasionally over the last several years, it didn’t seem as if he ever would. The program version has remained resolutely at v2.76 forever.
A close look at the website, however, reveals a clickable link to a new Cartes du Ciel, version 3.0, now in beta release . This new CdC is just now catching the attention of John and Jane Amateur, since development has been a little slow. In part this is probably because Patrick spent some of his spare time working on his outstanding freeware Lunar atlas program, Virtual Moon Atlas, and possibly also because Cartes du Ciel required a rework from the ground up. Developing the Linux version also undoubtedly took time too (a Mac version has been compiled, but according to Patrick there’s still a good bit of work to be done in that area). The good news? Cartes du Ciel v3.0 is fully useable in its current Windows beta .0.1.2 release.
What’s new? Other than the forthcoming ability to run on those other operating systems, the program seems to work better on my Win machines. It certainly looks better, with an updated and more modern appearance. While a few of the features of the “old” CdC aren’t working yet, there are some new ones, like multiple linked charts, that are already functional and which blaze new trails for the program. At this point, 3.0 seems pretty bug free (any remaining ones are minor), and core features, including image downloads and telescope interfacing (via ASCOM), are ready to go.
My advice? If you’re a Cartes du Ciel fan, you owe it to yourself to download 3.0 (you can continue to run 2.76 as well—a 3.0 installation will not overwrite the older version at this point). I think you’re going to like what you see. If you’re not a CdC user? Go get 3.0 and get started with the future of astronomy shareware. Prepare to be amazed at how good free astronomy software can be.
Monday, March 05, 2007
Well, muchachos, I didn’t get caught up in the minor bout of eclipse mania that swept through the amateur astronomy ranks last week. Leastways, I didn’t think I would.
Eclipse mania? Yeah, LUNAR ECLIPSE mania. After a Moon eclipse drought of several years, we were to be treated to a total one this past Saturday night, 3 March.
I’ve always been a Moon fancier, and eclipses are special for me. It was, in fact, the total Lunar eclipse of December 1964 that served to light my amateur astronomy fuse. For us veterans, a Lunar eclipse is maybe not the most exciting event on the astronomical calendar, but for a starry-eyed eleven-year-old it was something else. Not only was I seeing the sky do something in real time, I’d read up on the mechanics of the event beforehand, and the kids in my church youth group—and the adults—dutifully assembled to view this EDUCATIONAL event soon recognized me as the expert in astronomy and started asking me questions. If I had to point to a moment when I became an astronomer, that was the moment.
This eclipse, though? Sounded pretty punk. The Moon would not rise for me until totality was well underway. Might this be a public outreach opportunity? Didn’t sound like it—not much noise was being made about it in the media far as I could tell. I did get one call from the local newspaper enquiring as to whether we, The Possum Swamp Astronomical Society (PSAS), would be “doing anything" for it. “Nope,” I answered, “it won’t be much of an eclipse, and we have a public star party coming up later this month, anyway.”
Ho-hum, sounded like a real ho-hummer. Rather than sitting around planning a Lunar eclipse campaign (load up a truck full of gear and drive out to the club dark site for an unobstructed horizon), I instead loaded up Miss D, and Miss Lizbeth and we took ourselves to the annual chili cook-off in Bienville Square
Quite a bit of chili (and some beer) later, we returned to the old manse, I took a nap, and, when I awakened at about 5pm, I began to think “eclipse.” Wouldn’t be much, but I’d feel a mite guilty to miss it, I decided. Feeling a little logy, I didn’t want to mess with big scopes; the Meade ETX125, Charity Hope Valentine, and a pair of 15x70 binoculars would have to do. I did tote a laptop into the backyard, as I’m evaluating a program (Earth Centered Universe Pro) for a review, and figgered I'd kill two birdies with one stone by testing the software’s go-to capabilities with the 125 while I was outside. So…I dutifully connected ETX to PC and slewed to a few targets while waiting for the fat ol’ Moon to come up. When she did, I was surprised.
I was not impressed by the beauty of the eclipse as eclipses go—by the time Luna cleared trees and rooftops, totality was well over—but by the fact that even a run of the mill event like a minor Lunar eclipse still had the power to move me. Almost against my will, I found myself getting excited. I even ran inside and rustled up our little Canon Powershot point ‘n shoot digicam to snap the snapshot you see here (by the simple expedient of holding the little camera up to the ETX’s eyepiece).
Excited, yes. And I’m so glad. I hope never to lose the ability to forget about the nuances of SCT design, or the operational details of chilled CCD cameras, or the ins and outs of long exposure image processing, and just enjoy the simplest pleasures the night sky throws my way.