Sunday, September 28, 2008
Ethos Mania and the Cost of a Good Eyepiece
I can’t believe how much crying, whining, and downright bad-mouthing has resulted from TeleVue’s release (in batches) of their new Ethos 100-degree apparent field of view eyepieces. I know there weren't Internet astronomy forums in 1980, but I don’t remember all this teeth-gnashing and garment rending when the first Nagler eyepieces began to roll out. What am I talking about?
Take a stroll through Cloudy Nights, the Astromart discussions, s.a.a. (if you can stand the noise), or the Yahoogroups, and you’ll find, sure, plenty of posts enthusing about the new oculars and extolling their virtues, but you will find near-about as many comments like these:
“Elite and exclusive club.”
“Who wants an eyepiece that costs more than their telescope?”
“Some people are not impressed.”
“It’s all marketing.”
“Why pay that much for something that you can only see with peripheral vision.”
I’m talking Ethos MANIA, or maybe, more properly, Ethos Phobia. One telling thing? Most of the negative comments about these groundbreaking oculars have something in common: money. Sure, there are some posts that intimate the Ethos ain’t so hot optically or mechanically, but most grudgingly admit the new TeleVues are good, yeah, just not good enough to warrant their circa-600 buck price tags. Is the Ethos worth that much? What is any good eyepiece worth? What is a good eyepiece?
The first hurdle for the Joe or Jane Amateur who has decided More Better Gooder than the cheap Chinese Plössls that came with the scope is in order is “What is better?” Unfortunately, that is not an easy question to answer.
Frankly, for some folks, inexpensive imported eyepieces are more than good enough. For casual observers with longer focal length telescopes, there may be no reason to turn over part of the 401K (assuming it’s still worth anything) to Al Nagler. An f/10 SCT or an f/8 (or even f/6) Newtonian is pretty forgiving of eyepiece faux pas, and someone who only drags the scope out for the occasional backyard Moon party or a once-in-a-while trip to the club dark site will be very well served by the ubiquitous Plössls.
Cheap as they are—many now hover around 30 bucks—most modern Plössls are amazingly good. Much better than the dratted Modified Achromats and such that were standard fare for the stingy astronomer up until the 90s. I am particularly enamored of Gary Hand’s house brand (“GTO”) Plössls, and really am amazed that eyepieces a million times better than the Kellners and Ramsdens of my youth are actually cheaper in real dollars than those pieces of junk were.
Despite the value, utility, and ubiquity of the imported Plössl, there is no doubt the “serious” observer (whatever the heck that is) will eventually outgrow ‘em. After a while the characteristics of even “better” Plossls begin to annoy. One thing that gets old in a real hurry is their eye relief (or lack thereof). It’s OK at longer focal lengths, but becomes irritatingly tight as you go shorter. At 7-mm or so, your poor peeper is usually jammed up against the eye-lens of the ocular. And that ain’t all. While they serve well in longer focal length scopes, the Plössl’s limitations become evident as scope focal ratios get faster. In an f/5 the field edge that looked nice in an SCT may begin to enter gag-me-with-a-spoon territory. Other optical failings may also become more evident as optics get faster.
All that said, remember you are only talking about an approximately 50 degree apparent field of view (AFOV) with Plössls, and for that reason many of these eyepieces will do respectably on just about any telescope. The big reason most amateurs begin to desert the Plössl after a few years in our ranks? The soda-straw views. Let Jane Newamateur get her first look through a 70 degree or 80 degree AFOV eyepiece, and she will have a hard time going back to the fence-knothole view of Plössls.
Does everybody work their way from Plössls to Naglers, then? Not everybody. Planetary observers might suggest that if you are mainly interested in the Solar System it is possible to avoid widefields and do well on a budget by taking the path to Orthoscopics (which usually top out at about 45 degrees AFOV). Why spend for lots of field when you are only looking at the dit-dot in the center of the eyepiece? Quality Orthos, like those from University Optics, are good eyepieces, and are usually reasonably priced—but not always. Orthoscopics can be just as high as the latest Al Nagler creation; get a load of the recent Zeiss Abbe Ortho run by Baader.
So you can be happy with a 50 buck UO Ortho if Jupiter is you main love? Maybe, maybe not. I consider myself a fairly serious planetary observer and while I still hang onto my ancient set of Celestron “Circle T” Orthoscopics I admit I don’t use ‘em much. Yeah, when I’m looking at Jupiter or Saturn, I am mainly looking at the center of the field, sure. B-U-T…and this is just me…I still dislike the claustrophobic AFOVs of Orthos. Might the Orthoscopics be sharper and brighter than ultrawides like the Naglers (due to fewer lens elements)? At my age my eyes can’t tell the difference any more (if’n they ever could), and I just prefer space-walkin’, even in the bounds of Sol’s little kingdom.
So, a 70-degree then? You'll definitely save some money compared to a Nagler, but not a huge amount if you go top-of-the-line. You'll pay around 300 – 350 for a Meade Series 5000 Super Wide or a TeleVue Panoptic or a Pentax XW (on average; some focal lengths are cheaper, some more expensive).
What’s it like using one of these middle-of-the-road eyepieces? It depends, like all eyepiece questions, on YOU and YOUR scope. Yes, the apparent field of a 70 degree AFOV ocular is not, perhaps, in spacewalk territory, but, you know what? You may not miss the spaceship porthole too much. Especially if you use a driven telescope. Me? I’ve got a boxful of TV Pans, and despite what Uncle Al and Son do in the years that come, I ain’t letting ‘em go.
In my SCTs, the Panoptics and similar super-wides are close to perfection. Stars are dead sharp even at the field edge, and while 70-degrees ain’t 80-degrees, it still feels comfortable and expansive. Optically? All these upper crust super-wide eyepiece are very good, if some are maybe not quite as good as the Naglers (the Pentaxes may be as good if not better). I note, for example, eye placement is more critical with my 27 and 35 Pans than with the longer focal length Naglers. Mechanically, the Panoptics and Pentaxes are superb. The Meades are a step down, with me not liking their dadgummed “screw up” eye-cups. Turning these hard eye-cups to extend ‘em reveals a barrel covered with grease, some sort of weasel-fat based lubricant that inevitably migrates everywhere—hands, scope, charts, etc.
300 buckeroos not your idea of “inexpensive”? It’s certainly possible to go cheap, or even real cheap, with super-wides. The Chinese factories know what you want. Almost every astro-merchant on the ‘net is selling some kind of bargain basement 70 degree job. And there are some real bargains out there. Fact is, it’s fairly easy to produce a nice-performing super-wide. Standouts? For my money the Hyperions from Baader and the Stratuses from Orion (Telescope and Binocular Center, that is). Both series feature numerous focal lengths, good performance even in fairly fast scopes, and prices that top out at about the hundred-an-a-quarter-mark. Still too rich for your blood? Get down and dirty with Orion's 66 degree AFOV Synta-made Expanses for about half that much.
What’s the penalty for being able to pay the mortgage this month? The Expanses are only available in a few focal lengths: 6-, 9-, 15-, and 20-mm, and unfortunately offer fairly poor performance in fast scopes. With “fast” being “less than f/6.” On the other hand, in an SCT the Expanses will make you hop up and down and yell “YEAH, BABY!” I will confess I often use these buggers with my f/4 StarBlast, where all perform surprisingly well with the exception of the 20-mm. Even if they are a couple of steps down from the Pans, a set of four for less than 200 is hard to beat. If you hunt around, you may do even better, since Synta markets these through other folks—Adorama Camera in the past—sometimes for even lower prices. Again, I just loathe them teeny weeny keyhole views of the Plössls and Orthoscopics, and prefer the Expanses, warts and all.
Since Unk Al gave birth to his first Nagler dern near 30 years ago, “ultra-wide eyepiece” has been synonymous with “Nagler eyepiece.” It’s easy to see why when you plop one in your focuser. The Big Circle is just part of the attraction. In a longer focal length telescope, or in a fast one equipped with a coma corrector, the view in the Naglers is heaven: Tiny little stars at the edge, and an obvious absence of the gremlins that spoil the spacewalk party with lesser eyepieces: astigmatism, blackout, internal reflections, and the rest of that demonic gang. The only down-check (for some users) is that Nagler eye relief can be a little tight. Otherwise—until recently, anyhow—this was as good as it gets. Oh, there is one other itty-bitty caveat in addition to eye relief: Price. Naglers start at ‘bout 300 for the 2.5-mm and go all the way up to 690 for the 31-mm, the storied Holy Hand Grenade.
Too much, way too much, non-astronomer hubby or wifey says? There are quality alternatives. Starting with the Meade Ultra Wides. Not too long after Al’s Naglers hit the streets, Big Blue (well, back then, anyhow) came out with a series of—ahem—“similar” oculars. Lotsa folk liked ‘em, with the main criticism being that Meade never updated its optical designs like TeleVue kept doin’.
The Meadesters did revamp these eyepieces a few years back, with the barrels being made a bit more modern-looking and the coatings being brought into the 21st Century. Optically, they are good, if not as good as the TVs. Mechanical/build quality is OK, with my main complaints being a certain occasional non-uniformity in their otherwise good coatings and, as with the Super Wides, the weird eyecup arrangement and its grease-smeared barrel. Price-wise, they represent a significant savings over the Nags, with the Meade 4.7-mm going for 200, and the price climbing to “only” 450 for the 30-mm.
If even the Meade prices make the eyepieces an unrealazable dream, there may be salvation for you in the form of the William Optics Uwans. “Uwan” is not a city in China; it is WO’s acronym for, you guessed it, “Ultra Wide Angle.” Optically and mechanically these eyepieces are superb, fully competitive with the Naglers and better both optically and mechanically than the Meades in this old boy’s opinion. Cost is crazy-good for eyepieces at this level, with the Uwan 4-mm going for 200 and the massive 28-mm a “mere” 350. If there is a sour note here it is that these eyepieces are only available in four focal lengths: 4-mm, 7-mm, 16-mm, and 28-mm. Otherwise, they convinced me that there can indeed be both “cheap” (relatively) and “good.” Read all about ‘em here.
You ain’t about to be spending 200 bucks on an eyepiece what with the baby needing Pampers again? As above, you can taste spacewalking for much less than the TVs, Meades, or even the Uwans, but be prepared for a little bitter with the sweet. I’ve tried quite a few 50 – 100 dollar ultra-wides and have not been completely satisfied by any. Probably the best of the lot is an eyepiece sold by several vendors including Anacortes (“Birdseye”) and Owl Astronomy (“Knight-Owl Ultra-Wide”). These are not bad oculars, and I have had a lot of fun with the 30-mm and 11mm Birdseyes. In my SCTs they do yeoman duty as “public star party eyepieces,” presenting decent—if hardly perfect—images to the wee folk and their parents. At these prices at least there’s no need to agonize over mascara and lollipop deposits. Do be aware that if your scope is faster than f/6 or so you may find the field edge of these eyepieces and their sisters TRULY UGLY. Nevertheless, good buys and a hell of a lot better than the Ramsdens—or even the Erfles--your Uncle grew up on.
The Ethos Factor
There things stood until last year, TeleVue remained the king of the hill, but found Meade and William Optics nipping at their heels. Until Ethos time. When we began hearing rumblings that the Naglers were gonna announce something new—really new—at the 2007 NEAF. That turned out to be something most of us had given up on as the merest fancy: a 100 degree AFOV eyepiece. Oh, years ago, Ernst Leitz, had sold an ocular in the 90 degree range, but it was hellishly expensive (one-THOUSAND George Washingtons), only available in one focal length, had not been designed to be a scope eyepiece in the first place, and in some respects, blackout especially, it was not perfect in that role.
While the Ethos, initially available in a 13mm focal length, was not 1000 bucks, it was not cheap or even close to it, going for just over 600 dollars. Almost immediately, healthy amounts of skepticism were generated. 600 is a lot for a 13mm—or any focal length—eyepiece. The subsequent release, an 8-mm, was not much less costly, and the forthcoming 17-mm (2009) will be even more. What do I say about that?
It’s up to each and everyone of us to make the subjective decision as to whether these eyepieces are “worth it.” Me? I’m lucky enough to have started down the path to Ethos heaven already. And you know what? I don’t feel a bit guilty. I am at that rather advanced—kaff-kaff—stage in life where I can afford a few nice things. If I happen to spell that “Ethos” instead of “Rolex,” well, so be it. It ain’t actually that bad anyhow. I find it much easier to round up the 600 – 700 Ethoses demand than I did the 200 the first Nagler commanded (200 1980s dollars is 500 2008 dollars, by the way). Anyway, it is not my goal to convince y’all you need to write a check to Uncle Al. My purpose is just to let y’all know what I have experienced with this new tool.
And so…and so…I was finally able to hold the nine-days-wonder in my hands. I was impressed yeah, but not exactly overwhelmed. This eyepiece was not that different from my beloved Nagler 12-mm Type 2. Barrel was a little longer, and maybe the whole package looked a little more “modern” whatever the heck that means. The eye-lens was impressively large and beautifully coated. The field-lens/Barlow end? Not that different either. With this eyepiece Al and David have returned to the “hybrid” 1.25-inch/2-inch eyepieces of yore. Just like my 12-mm, the 13E includes that weird little screw that screws into the skirt and for which I have never been able to figure out a need/use. The Ethos also “features” that accursed barrel undercut TV eyepieces are (in)famous for. Surprisingly, the Ethos, while more physically imposing than the 12-mm Nag, seemed a little lighter.
While, yes, I was impressed by the new TeleVue, which definitely looks updated without going to radical extremes as Meade did with its new Ultra Wides, I still felt, oh, I dunno, a little ho-hum about the whole shebang. It didn’t glow a radioactive purple. Heavenly choirs did not chant “GLORY TO AL IN THE HIGHEST!”
Yeah, the advertised AFOV aspect was tempting; 100 degrees versus 82 degrees is almost 20 more degrees, quite a lot of degrees when you’re talking apparent field. Still, I didn’t expect my reaction to be anything like what I experienced the first time my eye went from the 45 degree AFOV of a Kellner to the 82 degrees of my first Nagler. The Ethos would be impressive but hardly worthy of making a skinflint such as myself dip into his coffers. Right? Right? With the Sun below the horizon, we got one of our scopes, a fast 8-inch Newtonian, ready to go, gently and carefully inserting that expensive glass into its focuser, and pointing to M42, which was nearing culmination.
What do I remember next? Pat took a look and started squawking. At first I thought he musta aspirated a pork rind. It soon became clear from his wild gesticulations, however, that he wanted me to look through the eyepiece. I did. And I was a goner.
What I keep telling people was the biggest surprise? That what struck me first was not the 100 degrees. No, that was the last thing I noticed. The first thing that hit me was M43’s dark lanes. There is no doubt that Chiefland is dark, has great transparency, and has stable seeing, but I have rarely seen the dust lanes criss-crossing M42’s little comma-shaped companion stand out more starkly than they did in this eyepiece on this evening. It’s a cliché, but it looked like a photograph. What else? The high contrast all across the field. And the tiny, sharp stars edge to edge. The incredible sharpness, as a matter of fact, of everything in the field. There was no point in ruminating further. I was sold.
When we got home, my beloved Nagler 12, which I’d had since Miss Dorothy gifted me with it on Christmas 1995, went up on the Astromart. I bought my first Ethos, and I will tell you I will not stop until I have THEM ALL. Does that mean you need them or should want them? No, not necessarily. Again, what’s a good eyepiece for you depends on you and your scope. The Ethos is that good eyepiece for me, however. I’ve never seen one better. The Internet carping? Oh, it still goes on. People want controversy and drama—it adds a little spice to our otherwise sedate passion, I reckon. Here’s my response to the naysayers, assuming a response is needed:
I’ve been looking through eyepieces for over 40 years. Believe me, this is no gimmick. The “100 degree” bidness is just one aspect of Ethos greatness.
“Elite and exclusive club.”
The folks who’ve entered the Ethos ranks who I’ve encountered don’t fit that mold at all. Most of ‘em are serious about observing—or want to be—that’s all. Nothing sinister. No Bilderberger style conspiracy. I’ll admit some new Ethosites are a bit excited. But why should they be singled out for special scorn ahead of the folks who buy expensive APOs, or humongous dobs, or fancy CCD cams and occasionally crow a wee bit too much about their new obsession?
“Who wants an eyepiece that costs more than their telescope?”
Not even an eyepiece that can make a 400 buck scope perform like a million bucks? Most folks will not need every single Ethos that TV offers up, anyway. Even if you bought all of the four that have been released/announced so far, that would require an investment of around $2500. How much did you pay for that pair of jet-skis that sit in the carport most of the year? Or that bass boat? Or that four wheeler? Or any of the other toys the middle-class in this country don’t blink an eye at in shelling out for?
“Some people are not impressed.”
It is your right NOT to be impressed. Nobody is going to twist your arm to buy an Ethos or shun you if you don’t. I would urge you to actually GET OUT AND LOOK THROUGH ONE before you decide you are not impressed, however.
“It’s all marketing.”
It’s not a gimmick and it’s not marketing either—not that marketing is a bad thing, necessarily. An impressive aspect to the Ethos story? Most of the enthusiasm has not been generated by the (minimalist) TV marketing, but by word of mouth from your brother and sister amateurs. That oughta tell you something.
“Why pay that much for something you can only see with peripheral vision?”
Me-myself sees the field stop easily. It’s not off in some peripheral na-na land. And, once more, the huge AFOV is just part of these eyepieces’ allure.
I have an idea why some are. This has more to do with the chatter about the Ethos than with the eyepiece itself. I find myself feeling this way about Stuff occasionally, too. I heard enough jibber-jabber about American Idol, for example, to make me resolve to never, ever watch an episode. Thing is, though, sometimes that is shooting yourself in the foot. I missed every episode of Idol without knowing whether it was really good or bad. I just didn’t like the chatter surrounding it.
I have no doubt American Idol ain’t Shakespeare, but the Ethos is the Shakespeare—and Cervantes, and Dante, and Melville and Moliere—of eyepieces and if you don’t allow yourself the chance to experience it, you may be sorry later. For sure, it’s less painful to buy eyepieces as they come out than to wait a few years, have the epiphany that, yes, they are that good, and have to start the daunting task of chipping away at a set of five—or ten.
Could I get along without the Ethos? Sure. I’ve had wonderful nights under the stars, countless wonderful nights, with no-name Kellners and Modified Achromats. But now I don’t have to and I don’t want to anymore. I’ll admit the Ethos has spoiled me. I am loving every minute of it.
I never did buy the entire set of Ethoses, and not because of their prices or me not needing all the focal lengths that have become available over the last decade. It was because of two little letters: "E" and "S." It wasn't long before Explore Scientific, the Chinese-owned outfit run by Scott Roberts (formerly of Meade) brought out their own line of 100-degree wonders. Some focal lengths were priced at about half the cost of the TeleVues.
I was skeptical about the ESes at first, but a shoot-out me and my buddies did one Chiefland night between the Ethos 13 and the 14mm ES made me a believer. Was the TV slightly better? If it was, my middle-aged eyes couldn't see the difference. While I've held onto the two Ethoses I bought, and still love them, when I've needed new focal lengths I've turned to ES, who've prospered and thrived, and are now offering 120-degree AFOV eyepieces (!).
As I predicted, I've become a real fan of the Chinese 70-degree range eyepieces. The really inexpensive ones are still not as good as a Panoptic, sure, but the ones I have are more than good enough for me.
Otherwise? I've stopped buying eyepieces for the most part. I am mostly an imager these days (though that may change if I get to work on a proposed book on backyard visual astronomy), and I am not interested in collecting eyepieces just to be collecting, so I haven't bought an ocular in quite a while.
What I remember fondly, thinking back to the time this article was written, was all the excitement the Ethos stirred up in us. I haven't felt excitement like that in amateur astronomy in a while now.
Sunday, September 21, 2008
Amateur Radio and Amateur Astronomy: A Cautionary Tale
I’m guessing most of you know at least a little about amateur (ham) radio. There’s always been a lot of overlap between these two “scientific hobbies,” and I’d bet quite a few of y’all don’t just know about amateur radio, but are hams, maybe even active hams.
And how is ham radio? If you’ve been keeping up with it, even casually, you know that all hasn't been well in amateur radio for the last couple of decades. There were problems, big problems. Luckily, changes have been made.
Ham radio is growing again. The increase in new licensees, new hams, is frankly amazing now, but I don’t think any OT (Old Timer) will disagree with me when I say it was a rough twenty years or so. So what? I think amateur astronomy is in fair shape. But there's no denying it's got serious problems just as radio did. Largely due to the fact that it is now mostly a pursuit of aging baby boomers. Perhaps the travails—the mistakes—of our sister obsession might be instructive.
In addition to drawing audiences with some overlap (many nerds), ham radio and amateur astronomy share a similar heritage. Both are reasonably young pursuits, just under a century old in both cases. While many folks contributed to the start of both avocations, two names stand out as being responsible, more than anybody else, for the shape of things that came: Hiram Percy Maxim and Russell W. Porter.
Maxim, son of the inventor of the Maxim machine gun, was undoubtedly a genius. Like his daddy, he was inquisitive and mechanically inclined, but soon went from tinkering with the new-fangled internal combustion engine to playing around with the even more sci-fi – pie-in-the-sky radio stuff.
Good as he was at nuts and bolts—and later wires and “valves”—Maxim’s real genius was for organization. You can still see his original “rig” (radio), “Old Betsy,” on display at American Radio Relay League headquarters in Hartford, Connecticut, but Maxim’s greatest creation, and his real legacy is the ARRL.
Hiram started his League as a means to relay messages across the country in the days when hams used long-wave frequencies and couldn’t dream of spanning the continent with one transmitter. This original purpose—relaying emergency communications traffic and other serious stuff—marked the ARRL's, and much of ham radio’s, public face in the ensuing decades. Sure, ham radio was fun, but in the background there was always the Old Man with his serious mien looking on. Even after he passed on into the ether in 1936 he continued to be a strong force in our hobby. Ham radio wasn’t just some hobby like stamp collecting; it was serious. For many of us, very serious.
The history of amateur astronomy? The same, yet different. Some folks will maintain that the birth of amateur astronomy came on a lovely Tuscan spring evening in 1610 when Galileo first turned his little telescope on the sky. Well, sorta. But, truth be told, the amateur astronomy we know, like ham radio, began in the early days of the twentieth century. At this time, public education had finally taken root (temporarily at least) and scientific curiosity was aborning in the good, ol’ U.S. of A.
Like Maxim, Russell Porter was possessed of a magnificent obsession: astronomy and, most of all, telescope making. This struck a chord with a surprising number of otherwise normal guys and even a few gals and soon this telescope business wasn’t just a fringe occupation, but, as Arlo Guthrie says, A MOVEMENT.
While Porter was no doubt the driving force behind this movement, he did not, as Maxim did, organize amateur astronomers into a national group. That task was fostered by two other famous amateurs—icons, really—from the early days, Leslie Peltier and Albert "Unk" Ingalls. The organization that resulted from their early work, the Astronomical League, didn’t get rolling until 1947.
I’ve been going on about the similarity of ham radio and amateur astronomy, but there are big differences. As above, the Astronomical League was a long time coming, while the American Radio Relay league was there from almost the beginning of amateur radio. Why? In addition to the fact that none of the amateur astronomer forebears had quite the single-minded vision of Hiram Percy Maxim, there are a couple of other reasons.
Most importantly, amateur radio lives and dies by the actions of the federal government. The Washington Goobers have come close to legislating ham radio out of existence a time or two, and most (though not all) hams have recognized the need for a strong national organization to deal with threats from our government and foreign ones. While there aren't many commercial interests looking longingly at hams' HF allocations today, there is still work for the ARRL. Industrialists have just switched from longing for more HF band space, to salivating over hams' VHF/UHF/EHF allocations.
Ham radio is also different from amateur astronomy in that it’s a licensed activity, and that the federal government has long relied on hams themselves to aid in enforcement and licensing issues. Hams have always striven to be self-policing and, to the extent possible, self-regulating. Amateur astronomy has nothing comparable to any of that, and our national organization is less involved in and less important to amateur astronomers.
While amateur astronomers do come into contact with government when it comes to issues concerning the threat to the hobby posed by light pollution, that threat is a more nebulous one than that of spectrum snatching high-tech companies. It is also a threat that’s recent enough that it wasn’t a motivation for the birth of the Astronomical League.
Why else don’t amateur astronomers have an ARRL of their own? Maybe amateur astronomers are a wee bit less gregarious? After all, much of the time astronomy is a solitary pursuit. Even if you’re observing with a group you are mostly focused on your scope and the wonders in your eyepiece, not what your buddy is trying to say to you through 75 meter QRM and QRN on the Saturday night net. In part, in large part, amateur radio is about communicating with your fellow humans, while amateur astronomy is about trying to understand the non-human and maybe even inhuman.
Also, maybe because of that lone-wolf orientation, many of us U.S. of A. amateurs seem suspicious of powerful national organizations. They don’t want anybody telling them how to do amateur astronomy (some reserving for themselves the right to tell fellow astronomers how to observe).
More than a few amateur astronomers also have valid concerns about what the national organization, the Astronomical League, does for them. At one recent astronomy club meeting, a member challenged me to tell him what the AL does that's worth the club's yearly dues as an affiliate astronomical society. About all I could come up with was "observing clubs" and "The Reflector" and couldn't help feeling I'd proved the questioner's point for him.
Also, maybe because of that lone-wolf orientation, many of us U.S. of A. amateurs seem suspicious of powerful national organizations. They don’t want anybody telling them how to do amateur astronomy (some reserving for themselves the right to tell fellow astronomers how to observe).
More than a few amateur astronomers also have valid concerns about what the national organization, the Astronomical League, does for them. At one recent astronomy club meeting, a member challenged me to tell him what the AL does that's worth the club's yearly dues as an affiliate astronomical society. About all I could come up with was "observing clubs" and "The Reflector" and couldn't help feeling I'd proved the questioner's point for him.
Anyhow, despite the differences between these “legislated” and “non-legislated” hobbies, their histories are much the same, and a look at where amateur radio has been and gone over the last 40 years may indeed be instructive and cautionary.
Yeah, ham radio began at the turn of the century (the previous turn, that is; I keep forgetting), but in some ways, it didn’t really start cooking till after WWII. Not long after the formation of the ARRL, amateur radio went off the air for the duration of WWI. Hams worked like heck to bring radio back after the Armistice, but just as things were going good the double whammy of the Depression and WWII hit.
The Depression was probably not all bad for ham radio, since it encouraged creativity: how do you make a transmitter out of stone knives and bear skins? It was also a fairly cheap way to entertain yourself when nickels were hard to get. But folks had other things on their minds at the time (like eating).
By 1940, restrictions were already being placed on ham radio as the war clouds gathered, and ham radio was shut down for the duration for all practical purposes after Pearl Harbor. With VJ day, though, ham radio came back with a vengeance, aided by a good postwar economy and tons and tons of war surplus radio gear and parts (there was so much of that that we were still enjoying the bounty through the 1960s).
The tenor of the times helped, too. Concerns about the (very real) threat of thermonuclear war, and the need for alternate communications methods for Civil Defense assured that ham radio was both an exciting and valued way for young men to get their kicks in the 50s and early 60s (there were a few “YLs,” women ops, back then, but not many).
The space race helped almost as much as the arms race, as ham radio was looked on as not just a way to chat with your buds on the Friday night net, but as something EDUCATIONAL for kids. Scientific. There were probably more high school radio clubs then than ever before or surely since. Almost unbelievably, for a little while there, being a ham was not the badge of uber-nerddom, but genuinely cool.
There, in this Golden Age, hams remained till the sixties began to wind down. It almost seemed as if amateur radio were on the verge of gaining mass acceptance/popularity. Down here, there wasn’t just a radio club (no amateur astronomy club), there was a large and active ham radio club. A club filled not just with geezers—they were the minority—but thirty-forty-somethings, YLs, and even, yes, us teenagers despite the other—ahem—“activities” that began to attract us younguns’ notice as the Summer of Love came and went. Unfortunately, change was coming and soon.
The ARRL had become concerned about “appliance operators,” who some thought represented a decline in technical competency in ham radio. Traditionally, hams had built their gear. Well, sort of, anyhow. Most hams didn’t attempt the rather arcane art of building radio receivers, sticking with transmitters—AM and CW (Morse code) transmitters—which were relatively easy to homebrew. As the 1960s dissolved in a Purple Haze, though, most hams, new and old, began to buy rather than build. Why? Mainly due to one thing: Single Sideband (SSB).
This was a new (to the ham radio rank and file) voice communications method that was much more efficient than Amplitude Modulation. Unfortunately, an SSB rig, especially a transceiver (which combines the functions of transmitter and receiver in one box, both sharing many of the radio's components), which was what most hams now wanted, was impossible for many hams to construct from scratch. My Old Man did it, but he was a broadcast engineer who could sketch a schematic and sling a soldering gun with the best of ‘em, and even for him this was not a trivial project. Another factor in the decline in homebrewing was that the flow of free or nearly free war surplus parts had begun to slow to a trickle (Vietnam produced little in the way of surplus radio gear).
The ARRL began to believe there was a CRISIS IN HAM RADIO. Hams were becoming just like the dreaded CBers—buying a radio to chat with Good Buddies being the sole focus of the Appliance Operators. Then the League made a mistake that was to slow our growth for a long while. Instead of doing something to gently encourage hams to become more involved in the technical side of the hobby—developing course materials/project kits for the clubs, for example—they decided on a more proactive and draconian approach. What was needed, they said, was harder licensing exams.
Except in the very early days, ham radio has always required a license, and an exam has been the price of that “ticket.” Until the end of the sixties, that license required nothing more than a modest theory exam and a Morse code test that was slow enough that most anybody (though not everybody) could pass it. The ARRL decided the way to increase the proficiency of hams was to force them to undergo more difficult exams. Ham radio’s frequency space would be ghettoized. If you chose just to stick with your old license, you could still get on the air, but only in crowded and less desirable segments of the amateur bands.
How could the ARRL impose this system, which they (and the FCC) called “Incentive Licensing,” on hams? They’d long had the ear of the Federal Communications Commission, and in internal amateur radio matters the FCC almost always deferred to the ARRL. Whether it was the ARRL or the FCC who first came up with the idea of Incentive Licensing depends on whose history you read, but there is no doubt the A-Double-R-L was instrumental in seeing this scheme become a reality.
The result? Some hams just upgraded. If you were lucky, you had a facility for taking tests and copying Morse code. Having somebody like my Old Man who could make the most arcane radio technology understandable with a few pencil scrawls on one of Mama’s paper napkins didn’t hurt either. For me, the theory and the 20 words-per-minute code test of the Extra Class license were doable (if not exactly a walk in the park). If you were not so good at tests and at deciphering dah-dih-dah-dih/dah-dah-dih-dah? Too bad…no soup for you.
Quite a few hams became discouraged by the situation and dropped out at this time. Why, they understandably wondered, wasn’t there a place for ham radio operators who just wanted to operate? Wasn’t being a good radio op just as important as answering questions on a government test?
Eventually, ham radio lost a lot of old timers who couldn’t or wouldn’t upgrade to the Extra Class license, and who also couldn’t adjust to life in the 75-meter “General Class” band-segment zoo. Undoubtedly quite a few new hams dropped out as well. After struggling to learn the Morse code and theory so they could finally have some fun, they were informed there would be yet more code tests and electronics exams before they would be allowed to have the real fun.
As early as the 1970s, Morse code was dying as a valued mode for commercial and government communications. Modern technologies like SSB and, increasingly, advanced (digital) communications modes had been pushing CW out of the commercial sector for years. But ham radio as practiced in the USA still required the initiate not just be able to copy the code, but be proficient.
That proficiency wasn't easy for everybody to attain. Even passing the General Class 13 words per minute test was utterly impossible for some. While International communications treaties required ham radio licensees to demonstrate a knowledge of Morse code, that requirement did not mandate expert proficiency. 5 w.p.m. would satisfy it.
Unfortunately, not everybody’s brain is wired right for CW. Ain’t no shame in that. Some have a talent for it, some don’t. Ham radio Old Timers’ attitude? Beyond talk about CW being useful for emergency communications, it supposedly being possible to copy the code when nothing else will get through an H-bomb-disrupted ionosphere, there was a sub-text: “The code is good because it keeps the riff-raff out.”
It certainly kept a lot of people out of ham radio—if not necessarily or always the riff-raff. My old man was strongly in the OT ranks, but even he would sometimes admit that maybe 20 w.p.m.—or even 13—was too much. He’d had a friend who dearly loved the idea of ham radio. He was sharp technically, too. Unfortunately, this prospective ham just could not learn the code, finally giving up after multiple attempts to pass the test. Ham radio, the OM reluctantly admitted, lost a person who would have been a huge asset.
Incentive Licensing and the code really didn’t have a huge initial impact (I’m not sure how many of those General Class hams who swore they’d tear up their tickets rather than try for the new Extra Class really did that). It was more like a potent but slow-acting poison. The effect was eventually felt in the expected way: Fewer and fewer new hams. Sure, as the 80s came, the ARRL tried to lure video-game crazy younguns with visions of computerized radios and digital communications modes, but when the newbies showed interest they were told, “Cool, welcome! But first you’ll have to learn Morse code just like grandpa did!”
At a hamfest I attended about ten years ago, I was struck by the fact there were few, very few, attendees who appeared to be younger than their mid-fifties. A relatively small deep-south amateur radio gathering does not tell the entire tale, of course, but the outlook appeared grim. Would ham radio fade away as the last of us Baby boomers checked out?
Then everything changed. The ARRL saw the light and thanks in no small part to their efforts with the FCC, the Morse code tests became a thing of the past, dropping to 5 w.p.m., and then disappearing altogether. The only question was “Is it too late?” I am happy to say the answer was "no." Amateur radio licenses are up, and if this continues, the avocation will soon be back on an even keel.
Unfortunately, ham radio squandered three decades during which we should have been expanding. Now we are faced with the task of rebuilding and convincing young folks that fancy transceivers are more fun than chatting on a cell phone or typing on the Internet or playing an Xbox.
Ham radio, schmam radio, what does all this junk have to do with amateur astronomy? The parallels are clear. Come on, admit it, you’ve been one of the group of geezers at the local club meeting lamenting the fact that these gull-derned sprouts and newbies don’t know the sky, don’t want to learn the sky, and just want to—darnit—have fun looking through their telescopes.
Yep, go-to is amateur astronomy's Morse code. We do have one advantage hams didn't; you don’t have to get a license to use a telescope on the sky. There is no way to force a novice to learn the constellations when she enters our ranks. Well, almost. If said novice joins a club that is dominated by OTs (“I paid my dues, you’ll pay yours”), peer pressure may do it.
I recently ran across a young squirt at our local/regional star party cruising the sky with his brand new LX200 GPS by means of finder and hand-paddle. A few questions soon revealed that this was not due to a self-motivated desire for self-improvement, but fear. He was genuinely afraid of what his fellow and senior club members would think of him if they caught him using go-to without knowing every darned star’s name. I tried to suggest he consider just having fun with his new scope, but he wouldn’t take the bait. I haven’t seen that young man in a while, and would guess the wonderful new scope has taken up residence in a closet and that he hasn’t been to a club meeting in long time.
Club meetings? Some radio club meetings with their impenetrable jargon and older and sometimes seemingly unwelcoming participants can be as frightening for novices as induction into a 19th Century East London murder cult. Sad to tell, astronomy clubs are much the same, and with radio clubs now attracting young folks again, many astronomy clubs are actually worse. I know there are a lot of nerds and geeks among us (yours truly included), but could we at least TRY not to scare off every single young man and woman who wanders into a club meeting?
Could we at least try not to show off our Special Knowledge right away? Could we try to refrain from locking Jane Novice in our steely gaze and asking, “Huh-huh, huh-huh, bet you can’t tell me NGC 6553’s Shapley-Sawyer class (giggle-snort)!” Ever think about inviting the (over 21) newbies out for a beer after the meeting and occasionally discussing the Saints’ prospects for this NFL football season instead of/in addition to the pluses and minuses of front/back illuminated CCD chips and the probable value of Lambda in the universe? No, I am not suggesting we change who we are, but if we want to go mainstream, we are gonna have to be a little more mainstream.
Why bother? What’s in it for us? Well, beyond an innate desire to see the avocation begun by Russell Porter (or if you prefer, Unk Albert or maybe William Herschel), continue down the generations, there’s a selfish motive. More folks = more stuff. Would you like to see Astronomy Technology Today twice as fat as it is? Would you like there to be an honest-to-god telescope dealer in your Podunk town? Would you like star parties every month of the year—big star parties with lotsa vendors? Would you like a grass roots local movement that forces the politicians to enact strong ordinances mandating sensible lighting? The way to get these nice things is not by being exclusive, but being inclusive.
In addition to making the face of amateur astronomy more welcoming, we’re gonna have to make it more diverse—if we care about the above good things. As I have preached before, that face will need to be younger, of different colors, and of different gender before we get to where I think we should be given our inherent appeal. Inherent appeal? Yeah, you see it at every public star party: The look of wonder on a housewife’s face when she gets her first look at the Moon through a real telescope. The attraction is there; we just need to find a way to capitalize on that attraction.
Ham radio? The ARRL and hams in general are turning in a new and better direction, and given the uptick in new licenses it is obviously not impossible that ham radio will soon be thriving again. The main lesson we can take from the hams' story? Let us welcome all and sundry into our ranks to enjoy our glorious avocation as they see fit. Let us have kids on our side in our ranks and let us co-opt and use technology for our advancement and benefit when it comes instead of fighting and fearing it.
73 de W4NNF
Next Time: Ethos Mania...
Sunday, September 14, 2008
The 37-Year-Old Telescope
Some Amateur Telescope Making projects are like fine wine. Set them aside for a while, let them mature, and they become sweet. Others? More like Boone’s Farm, muchachos. Let ‘em sit too long and they turn to vinegar. The question facing ol’ Unk was which category would the 37-year-old mirror fit into? I was finally, with the help of ATM Pat Rochford, determined to find out.
What kind of jibber-jabber is your silly ol’ Uncle spouting now? As always, it’s best to start at the beginning, and this beginning began a right smart while back. Let’s set the WABAC Machine for the summer of 1971...
For those of you who weren’t around for that halcyon year, the sixties had rolled over to the seventies the previous annum, but 1971 had more to do with the previous decade than with what was to follow. When I think about what we listened to and watched that year, I feel old, real old.
Naturally, music was in the air. The big news (for us silly kids, anyhow)? Former Beatle George Harrison’s Concert for Bangladesh. The surprise hit album? One that amazed and scandalized in those simpler times, Love it to Death by a dude calling himself Alice Cooper. Not quite your cup o’ tea? Gordon Lightfoot had a big hit with “If You Could Read My Mind.” Movie-wise we chose from flicks as diverse as Carnal Knowledge (real good) and Fiddler on the Roof (purty much the last victorious gasp of the traditional filmed musical). What were we watching on TV on the three channels that were all we had down in the Swamp? All in the Family and The Flip Wilson Show. Political news? Watergate was aborning but not with us yet. George McGovern was cranking up his ill-fated campaign, though. In science, Apollo 15 trumped everything else, naturally.
Like I said, long, long time ago. Sigh. Seems that way sometimes, too, though if I really concentrate I can still hear the faint sound of a sitar way off in the distance. What was your old Unk doing at the time? Purty much what I do now, obsessing about amateur astronomy. One thing was different, however. This may shock y’all, but back then, Unk, who is probably best known today as an ATB (Amateur Telescope Buyer), was an honest to god ATM, going so far as to grind, polish, and figure several Newtonian primaries.
I will admit that even then I was more interested in looking than making, so what got me involved in the grit n’ glass game? One thing: poverty. As I’ve mentioned a time or two, my prime instrument for the longest time was a Palomar Junior, a used 4.25-inch Newtonian from Edmund Scientific that I’d somehow been able to glom onto in 1966. While I loved that scope (make that “love;” she still occupies a hallowed spot in Chaos Manor South’s Massive Equipment Vault), I was becoming less and less satisfied with her.
Not only that: by the end of the 1960s the city began to catch up on streetlight installation. Until then, suburban mercury vapor lights had been fairly few and far between. Then, all of a sudden, there was one on the power pole in front of our house. The vacant lot next door where me and my buddies in our Backyard Astronomy Society held our star parties? Sadly, a house was built on it at about this time; luckily, it was bought by an understanding couple who turned off their porch light whenever they noticed me and my Pal were out and about.
Alas, this understanding and friendly couple moved away after a while, and next door was then occupied by decidedly peculiar and mean-tempered folks (the husband was a drunk and an absolute nutcase and the wife was just plain weird) who immediately decided they needed a couple of huge mercury vapor yard lights—probably in part to keep an eye on what that weirdo neighbor boy was up to at all hours of the night. By 1968, my poor Pal Junior was losing ground, showing DSOs not much better than what my first scope, a 3-inch Tasco Newtonian, had done.
Not that I hadn’t felt the stirrings of aperture fever before this time. From the backyard in the Pal Junior M13 was a (bright) smudge. What to do? Get a 6-inch, that standard of ADVANCED AMATEURS back then. B-U-T. The Edmund Space Conqueror and Criterion RV-6 Dynascope both hovered at 200 bucks, a seemingly insurmountable obstacle. Why, then, I’d follow in the footsteps of Russell W. Porter and my other amateur astronomy heroes and roll my own. Surely Sam Brown wouldn’t let me down? A mirror kit and a copy of his All About Telescopes and I’d soon be glob busting.
Lucky for naïve little me, one of my buddies and his dad had done a 6-inch mirror and they offered to show me the ropes. I doubt I would have gotten the project even an inch or two off the ground without their aid. With their patient instruction, though? Mirror making turned out not to be as tough as I’d feared. As I proceeded, I even managed to get The Old Man (OM) involved in the project—making a Foucault tester was just the sort of project he enjoyed.
I zinged along, not making too many mistakes. Oh, I had to back-up a grade or two of grit a time or two, learning in the process the valuable lesson that cleanliness really is next to Godliness—when it comes to making mirrors, anyway. Finally, on one pretty spring day it appeared I was done. I had managed to keep the focal ratio at right around f/8 or a wee bit more. Yeah, there was, I thought, still some of the dratted and dreaded turned-down-edge I’d struggled with, but I was convinced I was in “good enough” territory.
I’d originally planned on using vile chemicals to silver the mirror myself, but the Old Man put his foot down about that. He (to my amazement) offered to pony-up the simoleons required for aluminizing. Part of the reason was no doubt his natural generosity. The other part was, I suspect, his understandable reluctance to allow the frightening combination of his often-careless 14-year-old son and a batch of poisonous chemicals.
I also believe he had been bitten just a little bit by the amateur astronomy bug and wanted to give my little project the best possible chance of succeeding. Ham radio was his passion; he was a real Old Timer—W4SLJ, now a Silent Key—but some of my love for the night sky must have rubbed off in the course of those many evenings when I’d burst into the family room demanding he come out and look at the latest wonder I’d discovered with my 3-inch Tasco.
After a seemingly interminable spell, the mirror was back. The intervening weeks had not gone to waste, however, with me spending the time assembling something that resembled a tube (stovepipe) and a focuser (plumbing parts), and a "pipe mount," a German equatorial made of, yes, pipes. I did my best to get the RA and declination motions just as smooth as I could. Oh, the mess I made with valve grinding compound in the course of "lapping" the pipe threads. I thought Mama was gonna blow a gasket when I walked into the den in my good school clothes, which were now generously adorned with nasty black streaks and splotches.
I also needed a spider, a secondary holder, a secondary mirror, and a main mirror cell. I was truly astounded when the OM sprung for a secondary. The spider, secondary holder, and primary cell were a testament to Daddy’s metal-working skills, acquired in the course of many years of home-brewing his rigs (ham radios).
Frankly, the resulting tube and mount didn't look half bad, and I began to imagine actually using the scope on the sky. Nevertheless, I was scared. The OM seemed to have confidence in me, frequently asking what I’d use for my First Light object, but I wasn’t so sure. In fact, I was doubtful what I’d made would be much better than a shaving mirror.
First Light Night came and I braced for disappointment. Daddy and I hauled the whole business out into the backyard. This felt like a serous scope, at least. I hesitated, but the Old Man prompted, “Go on now.” I pressed my eye to the eyepiece of the finder we’d cobbled together (a couple of pieces of aluminum tubing, an old Wollensak camera lens, and a homebrew crosshair eyepiece). Homed-in on Saturn. I hesitated, “You look first Daddy.” He would have none of it. So, in went my 12mm Ramsden and to the eyepiece went my hopeful but wary young eye. Blob. Big blob.
I moved the focuser in and then out and, shoot, THERE SHE WAS! We were maybe two years past a ring plane crossing, so Saturn’s wondrous halo was nicely displayed. The planet was sharp, impressively sharp, with the Cassini division obvious almost all the way around. How did it compare to the Pal Junior? Brighter. Sharper, too, I thought. And what were those little dit-dots? Moons. In the Pal I could usually just make out Titan, but in my new 6-inch, three more were immediately obvious.
I pointed the new scope, my new scope, built by me, at many more objects on this storied night. I gave the OM plenty of eyepiece time, and he accommodated me by sticking with it for an hour or so before allowing that he reckoned he’d head on in to watch his show—probably Mission Impossible, which was his favorite that year. I, he thought, should press on. I did indeed keep it up well into the wee hours, until the carport light eventually flashed on and Mama appeared at the backdoor with her oft-recited “It is two o’clock in the a.m., young man, you get yourself inside.”
Naturally, I was purty pumped following my First Light success, and the months that followed saw quite a few incremental improvements to the 6: a real tube and a real rack-and-pinion focuser. I believe we got both from A. Jaegers of Lynbrook, NY, the same place I’d got the mirror making kit. Back in the Long Ago, Jaegers was almost up there with Edmund Scientific as the go-to guys for poverty stricken amateur astronomers.
Even before the improvements there was no doubt the scope performed well. M13 was a treat compared to what I’d seen in the 3-inch and 4 ¼-inch scopes. On good nights, it finally looked like a big ball of stars. And yet…and yet. Somehow it all seemed too easy. Surely I had no talent for this. What success I had was likely due to the help of my friend’s daddy, my Old Man, and Sam Brown. The images looked good, but I had a sneaking suspicion I had fouled-up. In my mind, the dimensions of that turned-down-edge grew and grew, despite the evidence my eye provided. My “flawed” 6-inch ate away at me, and I determined I’d do a new mirror, another 6-inch f/8, and I’d do it right this time.
When Mama asked me what I wanted for my birthday the following summer, I unhesitatingly chirped, “A 6-inch mirror kit from Jaegers; it’s only $12.95.” I had secretly wanted to ask for the step-up kit, which provided a blank with a pre-generated f/8 curve, but I thought $14.95 was probably more than the traffic would bear. Mama assented, though she was more puzzled than ever that I didn't want a slot-car like the boy next door, and that I was going to make yet another telescope—I already had two. How naïve the poor woman was to the ways of the astronomy equipment junkie! Actually, I didn't plan on a whole ‘nother scope, all I wanted to do was replace the mirror with one that was More Better Gooder.
In retrospect, it’s possible I was right. My first mirror was fine, but I could do better. I’d done more reading at the library and in Sky and Telescope and felt better equipped to handle the task. I exercised more care this time, too, especially regarding cleanliness. I also did my dangdest to keep that consarned edge under control, addressing that problem just as soon as it reared its ugly head. I also developed the idea that the most important part of the process is putting a good polish on the mirror. I don’t know how true that is, but it stood me in good stead. The end result after a couple of months of slow and steady work was a mirror—and a telescope—I was finally proud of.
There things stood till after my high school graduation in 1971 when I got bored. I had just graduated from high school, been accepted at a university, and in the wake of that excitement felt downright let-down. What to do? How about another scope? What kind of scope? The natural thing would have been an 8-incher, but the idea of doing a larger primary made me uneasy. Hell, even on the second six-inch I’d still felt like I’d been flying by the seat of my pants. Also, the cost of an 8-inch kit, about 20 bucks, was a bit rich for my taste—I now had to pay for gas for my 1962 Ford Galaxie (natch), you see. Doing an 8 would also have meant a new tube, a new spider, and maybe a new secondary and secondary holder..
Instead, I decided I’d do another 6-inch and reuse the current OTA, just cutting it down. Cutting it down? Yep, I’d decided I’d take on a challenge for 6-inch Newt number three, a FAST f/6 mirror. All the books on ATMing warned about how hard it was to do “high-speed” optics, and all advised beginners to stick with f/8. Well, hell, I wasn’t a beginner any more, was I? Where would I get the money for another Jaegers kit? I’d just ask for a combined birthday and graduation present package: the portable 8-track tape player I’d had my eye on and the kit (although I probably had enough abrasives left from the previous two outings to do another mirror). Mama didn't say a word as she wrote yet another check to Jaegers; she’d learned to humor her crazy son.
For some reason, my new kit arrived much sooner than the other two had, and I set about hogging out the deep(er) curve, working with a will as Bob Dylan’s Greatest Hits Volume II played on the 8-track. Before long I was polishing. As was my custom, I tried to do as good a job with that as was humanly possible, and prob’ly spent way too long in that endeavor.
I was just getting to the point where I figgered it might be time to try to do that dreaded f/6 parabola when the phone rang. Mama stuck her head out the door and announced it was one of my “crazy theatre friends.” "Crazy," yeah, but I could see Mama was actually pleased. My brother had been doing local theatre since he was the weest of wee sprouts, and Mama had enjoyed playing Stage Mother for years. To her, theatre was considerably more normal than young Unk's usual pursuits—amateur astronomy and comic book collecting.
Finished mirror or no finished mirror, I was having a great time over the course of what turned into my best summer vacation ever. I hadn’t lost interest in observing or in completing my primary, but in June I began dating a fascinating and lovely young woman, Linda, who I'd met at another community theatre, and she began to eclipse the Sun, Moon and stars for me--to put it mildly. Anyhow, as September came in it was time to forget grit and glass and head off to college. I was a little sad that I hadn’t quite finished the f/6, and resolved I’d just shelve it temporarily, finishing her up during Christmas vacation.
When Christmas vacation came, though, there was the holiday to enjoy with the love of my life. I didn't touch the mirror the whole time, and one day it migrated from the top of my dresser to a cardboard box in the closet in my old room. There it stayed while Miss Linda and I married, sadly, got divorced (my fault, to my shame), I continued college, did a tour of duty in the Air Force, unwisely got remarried, started a career, wisely divorced, and finally got hitched to Miss Dorothy (one of the FEW things this old boy EVER got right). Until…
One afternoon my observing buddy, Pat, stopped by good old Chaos Manor South to drink java and shoot the breeze about the current state of amateur astronomy as is our wont. That wasn’t all he came by for, though. Unlike me, Pat, despite a long amateur astronomy career, did not get bitten by the mirror making bug as a youth, but in middle age, and had been bitten hard.
He’d brought his current project, a 6-inch, by so he could get my opinion about its Foucault test appearance. After we’d taken a look at it, one of my few remaining neurons fired. “Hold on Pat; I’ve got something to show you.” I ran upstairs, rummaged around, and recovered the box containing the f/6 primary. It had been sitting around at Chaos Manor South for the last couple of years, since we'd sold the old family home after Mama went to her reward. The mirror almost went into the trash pile then, but I had the sense to look in the vaguely familiar box first, and there it was almost four decades later, a little yellowed, but unblemished.
Pat and I slammed it into the Focault rig he had brought with him. After squinting a bit, he pronounced that it appeared to be a good and smooth sphere and that WE WAS GONNA FINISH IT! I muttered that I didn't want to impose on Pat (though I often do), but that if he found himself looking for a project in the coming months, sure, slap it on the mirror stand and have at it. That was outwardly. Inwardly I was thrilled. After thirty-seven years this long-forgotten mirror would finally get to serve its purpose. There was more to it than that, of course; this humble six-inch Pyrex disk was a tangible link to my faded youth.
Pat did some further testing at home, verifying that it was a fairly decent sphere and that I had come reasonably close to f/6, with it testing-out right at f/6.3. Following that conversation, I didn't give the mirror much more thought for a month or two. What with the coming of summer and the inevitable clouding of our skies, Pat did indeed decide he wanted an ATM project, and got seriously to work on “Old 37.” The shocker? When he rung me up shortly thereafter to tell me it was done. It turned out I had been a mere 2 – 3 hours from finishing on the August afternoon when I’d gone off to flirt with the girls in the chorus of The King and I. Talk about irony.
Given the convoluted history of the mirror, the rest was anticlimactic. The only real eye-opener was how scarce ATM parts (at least for smaller aperture scopes) are these days. I did quite a bit of looking around before I found a secondary holder and spider that I thought would do, a nice set-up from the 1800 Destiny folks. Their name may be odd, but their service and their products are outstanding. One thing I did different this time was that I bought a curved spider. That eliminates the diffraction spikes that I, after 32 years using CATs, now find distracting. The focuser to go with it was a 2-inch Crayford from Orion. I was astounded at the quality of this unit, especially given its insanely low price. Smooth as butter, but capable of handling a decent payload.
Primary cell? I’d horse-traded some items with a fellow club member some years ago and one of the things I’d received was an 80s vintage Meade 6-inch mirror mount. With some cutting and fitting and modifying Pat was able to get it to fit my tubing. The last piece of the puzzle was a finder, but I intended to keep it simple with a good, ol’ Telrad. A base came promptly from one of my favorite newer dealers, Agena AstroProducts. All that remained was to get Old 37 aluminized.
I chose a standard aluminum coating, and used the same firm as when I had my 12-inch Dob’s primary recoated recently, an outfit local to my area of the country. The 12 had come back in just a couple of weeks, and I was hoping to get the same service on the six, since, almost in spite of myself, I was getting excited about the “new” scope. Alas, the two-week turnaround I’d experienced with the 12-inch did not repeat. After five weeks or so, I called the coater, who sounded annoyed to hear from me, but allowed that it had already been shipped. The day Old 37 returned I was both thrilled and dismayed.
The coating on the 12-inch had been just about perfect, beautiful even. The 6? I wasn’t impressed. In addition to one large and obvious sleek, there was a spot near the edge where the coating was obviously thin. An email to the coater got a prompt if somewhat snitty reply. Surely, if there were anything wrong with the coating it must have happened during shipping. If I wanted to send the mirror back, he’d take a look at it. Since the problems wouldn’t impact mirror performance, I demurred.
I do not, frankly, believe the coating problems happened during shipping, but I am not sure, and for that reason I am choosing not to mention the coater's name at this time. I was mostly put-out because, despite the standard coating, getting the 6-inch done had not been cheap; just the opposite, and I felt that this small mirror—which was nevertheless important to me—had not been given the care I’d paid for.
The long wait for the mirror had not been all to the bad. Just like way back when, it gave plenty of time for putting the OTA together. One thing I knew was that I wanted to paint the tube white. In the Olden Days, all telescopes were white, and I wanted Old 37’s paint-job to reflect her heritage. I also asked Pat to do two sets or mirror cell mounting holes, one for visual use, and one for imaging. Unless you use extension tubes for visual observing, it’s necessary to be able to move a Newtonian’s mirror up the tube in order for the scope to reach focus with a camera. Pat asked “how far,” and I ciphered out how far up the tube the mirror would need to move to come to focus with my Canon DSLR.
This was important, because I envisaged Old 37 being primarily an astrograph. Sure, I’d use her visually occasionally, but I thought she’d be just about perfect for picture taking. I’d wanted something a little shorter in focal length than my C8 for astrophotography, but with more aperture and image scale than my small APOs. I’d been considering a short Mak-Newt or a 4-inch ED refractor. If the 6-inch would serve, that would be a whole lot cheaper.
If not that cheap. Not including the mount (I intend to use it on my Atlas mostly), and not counting the cost for a mirror blank which I already had (not cheap now), I probably wound up with about 300 bucks in Old 37, which is likely one of the reasons people are not doing more ATMing. It’s much more practical and economical to just buy. An 8-inch Synta Newtonian on a good (non-go-to) GEM can be had for 600 bucks. A Dob is even less. A nice six-incher from Orion, for example, is crazy cheap--less than 300 dollars at the moment. Is it any wonder most clubs have shut down their mirror making classes? Now, as I said from the get-go, I am hardly a grit ‘n glass madman, but even I acknowledge that with the death of mirror making something has been lost from amateur astronomy.
And, then, finally, despite the twists and turns and passing of 37 summers, she was ready. Pat told me to grab a mount and head over to his digs for First Light. I packed up the CG5 and drove across the Bay-Way way too fast. On the mount, Old 37 looked just beautiful. If you didn’t look closely at the GEM and with all its computer frippery, she fairly reeked “1960s,” just as I’d hoped. Now it was time. With a gibbous Moon hanging in the sky, that was the obvious choice as First Light object. I was not disappointed. In an Ethos eyepiece, the Lunar terminator was just dead sharp and lovely (and I imagined it would have been almost as lovely in my Edmund Ramsden). Despite poor seeing and intermittent haze, Jupiter was a welter of detail when the air would settle briefly. I was sorry Saturn wasn’t available; seeing the ringed world on this First Light Night would have tied the bow on the package.
Bow-tying, you see, was what this project was really about, muchachos. I think Old 37 will perform brilliantly, and will report on my success there when we finally get some clear skies again. However that goes, something important has already happened. This long unwrapped package has had the ribbon put on it. The circle has been closed. A link has been forged with the long-ago summer of ’71. When I look at and through my wonderful telescope, I feel again the excitement of jumping into my jalopy to tear across town to my girlfriend’s house, where we’d sit for hours listening to Woodstock and solving all the world’s problems. Most of all, it brings back those first-blush nights when the stars were new.
Next Time: Amateur Radio and Amateur Astronomy...
Sunday, September 07, 2008
The Guiding Game
How can I adequately describe the pain we used to go through in order to get a fuzzy Kodacolor drugstore print showing a smudge that might look a little like M13? It went like this: you used a smaller telescope, a “guidescope,” piggybacked on your main instrument or you used an off axis guider (don’t ask) to monitor a “guidestar” during exposures. Why did we do that? Then or now, you unfortunately can’t just open the shutter of a camera (be that a CCD cam or a film cam) and do long exposure deep sky imaging. Most telescope drives are not blessed with gears good enough to allow that. Normally, you must guide, you must adjust the aim of the scope by minute amounts throughout the course of the exposure. If you don’t? You get nasty, trailed stars and a picture that goes into the trash can—real or virtual.
Back in the bad ol’ days, what this meant was that you kept a star precisely centered in the crosshairs of the guidescope’s high power reticle eyepiece for the duration of the exposure. If the star drifted the tiniest amount, you pushed a drive corrector of hand paddle button to re-center it. Back in The Day, most drives weren’t so hot—30 arc seconds of periodic error was common and good—so the star did a lot of drifting. But even with a good drive, you didn’t dare take your eye from that eyepiece. Miss one bump and you’d have wasted your time. You sat there and watched that consarned star for 15 minutes…30 minutes…an hour—as long as you could go. No wonder astrophotographers were looked on as the madmen of the amateur astronomy ranks; we had literally been driven nuts keeping that star centered.
Things are much different today, thankfully. You no longer have to watch that dadgummed star—a CCD camera does it for you. Once you get things set up and running, you can do what we all dreamed of doing way back when: open the shutter and walk away to look at the sky with your binoculars, eat a snack, or have a drink of—err…“sarsaparilla.”
Not only do you not have to keep your eye glued to the guiding eyepiece, the guiding quality delivered by one of these “autoguider” cams is far superior to what you can do by eye—better than what I could do, anyway. Even a minimalist setup is capable of guiding with better than 2 pixel accuracy, and many folks do considerably better than that. I find that at the relatively short focal lengths I image at, I can be pretty cavalier about setting up my guide system and--and this is a big deal for me--polar aligning. In most cases my guide cam can keep up with the errors—declination drift—introduced by my approximate polar alignments. I take relatively short exposures, and the computer stacks them later, making up for drift from frame to frame. That means I don’t have to worry about no drift aligning, which is not one of my favorite activities.
Is there no catch? Is there finally a free lunch? Is it really this simple? Just slap a guide camera and scope on your fave imaging telescope and have at it? Yes and no. Once you get into the autoguiding groove, it really is that simple. The devil comes in learning to autoguide, which consists of assembling workable equipment and setting up the software that does the work. Before you can wander around the field annoying your buddies while your CCD cam and autoguider do their thang, you must choose a camera and guidescope, choose an autoguiding program, choose a method of mounting guidescope and guide camera, choose a guide camera, and, hardest of all, get everything working together.
Almost any CCD camera can be pressed into service as a guide cam. There are only two requirements: that it be compatible with whichever guide program you plan to use, and, most importantly, that it is sensitive. A camera that is not very sensitive will soon incite you to hair-pulling as star field after star field lacks a suitably bright star for guiding (that is, bright, but not over-saturated). People have autoguided with unmodified webcams and things like the Meade LPI, but that is hardly an optimum solution, and I recommend it only if you absolutely have no choice. Even then, I suggest you look into modifying a webcam for long exposure. If you have the electronic skills to do the mod, or have a buddy who does, a webcam can work fairly well if it can be made to do 2 – 3-second exposures. Celestron’s inexpensive NexImage webcam is particularly easy to modify.Webcams do tend to be noisier than “real” CCD cameras, but that usually doesn’t matter much for guiding.
You can spend a wee bit more? One possibility is a used CCD camera of just about any kind. A tired old Starlight Xpress MX5 or SBIG ST-237 will work superbly (just make sure you can find a guide software package that supports the old clunker). A particularly nice choice is Meade’s original color DSI, which is what I use. Not only is it cheap—less than 200 bucks on Astromart, usually—it is quite sensitive. I don’t think I’ve ever been unable to find a suitable guidestar in any field, even though I normally restrict myself to guide exposures of 2 seconds or less.
Yes, you can also buy dedicated guide cameras, CCD (or CMOS) cams sold expressly for this use. Two standout examples are the Orion StarShoot Autoguider, and Fishcamp Engineering’s Starfish camera. Both sport one very nice feature that many general-use CCD cameras lack, an ST4 autoguide-output (more on that shortly). Downchecks? The Orion uses a CMOS sensor and is thus a little noisier and a little less sensitive than it could be. The Starfish is also a CMOS device and is also kinda pricey, $695.00 for the uncooled version, more than your stingy ol’ Uncle would like to pay for a guide-only cam. Is cooling necessary, by the way? Not really. Yes, cooled cams do mean lower noise—you are less likely to try to guide on a hot pixel than you are with an uncooled rig like the StarShoot. In truth, though, at the short guide exposures most of us use, cooling is really not necessary.
Anyhoo, let’s assume you’ve got yourself a guide camera of some kind and are ready to proceed. Next fork in the road is guidescope choice. Step one? If you’re an old-time film astrophotographer and manual guiding casualty like Unk, forget everything you were taught about guidescopes. Which was mainly that the guidescope should be as close in focal length as possible to the main scope. Longer was even better. That is simply not necessary in this day of computers and silicon chips. The average guide program does not care pea-turkey about the focal length of your guidescope, and shorter guidescope focal length has one huge advantage: a wider field and a larger number of guidestars to choose among.
What will work? Almost any small refractor is a good choice. I have successfully used a William Optics 66SD for lots of guiding, but today I am back to Old Reliable, my venerable 9 year-old Synta-Celestron Short Tube 80. This is, in fact, the guidescope I recommend for most ever’body. It features decent aperture, a short focal length, and a good build quality. One caveat: there have been quite a few ST80 clones sold over the last decade (like on Ebay). The original ST80’s focuser is a sturdy all-metal affair that can be locked down solid. Some of the clones have wobbly plastic focusers that will flex during guiding, ensuring your final image sports less than round stars no matter how well guide cam and PC did their job.
Next hurdle? How do you mount the guidescope? What I did for quite a while (after I stopped using that devilish off-axis guider) was piggyback a guidescope on the main scope, mount it on top of my SCT with a pair of adjustable rings. That can work well. Do be sure to get good, sturdy guidescope rings and a hefty mounting bracket. Any differential flexure between scope and guidescope brought on by a less than secure guidescope mounting arrangement, will, again, result in them derned trailed stars. If I wanted to do it right, I would probably look at Losmandy’s or ADM’s piggyback setups (to name just two outfits producing good stuff). After many years of experimenting, however, I’ve some to the conclusion that a side-by-side arrangement as seen in the image above is less prone to flexing and easier to work with. I have produced many, many well-guided images using piggyback setups, though; quite a few with the inexpensive but effective guidescope mountings sold by Scopestuff. I advise against scrimping in this area, however.
Camera? Check! Guidescope? Check! Guidescope mounting? Check! What else? Unless you are using SBIG’s ST4 or STV cameras, which feature built-in computers, you will need a laptop running a guiding software program. It is this program that is the brains of the outfit. It monitors the position of the guidestar on chip and issues guide commands to move the telescope when and as much as required. If you are as cheap as me, you will be pleased to learn you may not have to pay for a program. If you’ve purchased an SBIG camera, the soft that came with it, CCDOPS, will do a good job of guiding. If you’re using any of the top-of-the-line CCD camera control programs like CCDSoft or Maxim DL, these include guiding features that are more than sufficient. What if you are using a webcam? Gravitate to Astrogeeks’ freeware program MetaGuide. What do many, many of us use with great success, however? Another freebie, this one from Stark Labs (maker of the Nebulosity camera control and image processing program), PHD Guiding.
What makes PHD so good? Better than the guiding routines in many expensive CCD camera programs in many folks’ opinions? It’s a no-fuss, no-muss kinda thing. Most guide software requires you to fiddle with quite a few parameters before the software will guide right. PHD, in contrast, usually only requires you to pick a guidestar and push the “go” button. That’s why it’s called “PHD.” In this context, that does not stand for “Doctor of Philosophy” (though the author of the program has one), but for “push-here-dummy.” PHD does allow you to tinker with settings just like the other programs do, but that is usually not necessary. While I have had very good luck with CCDOPS and CCDsoft for autoguiding, these days PHD is about all I use.
What’s next on our autoguiding agenda? Now that you have all this stuff, you gotta hook it all together. Getting the image output of the camera to the PC is way easy; you just connect the camera’s USB output to a USB jack on the laptop (older cameras may have serial or even parallel format connections). Please be aware that some cams, like the Meade DSI, are powered from the USB bus and are also very power hungry. I find I need to connect my DSI to a powered USB hub, not just plug it into the laptop. If I do that, it completely overwhelms the little DC – DC powersupply I use to run the computer from 12vdc in the field. If at all possible, look for a camera that features USB 2 output rather than USB 1—if the camera image format is much above 640 x 480 in size, image download-time may play hob with your guiding over a USB 1 connection.
That’s the connection from camera to computer, but you will also need a path from camera (or laptop) to the mount for guide commands. There are two ways to go about this. The most familiar to many of the older CCD hands is “ST4.” This uses the autoguide input many mounts feature. The format is relay/switch closures (not serial data). This guiding system is simple and reliable. When the camera wants to move the mount east, it closes the east switch, just as if you’d pushed a button on the HC. Ointment flies? Only that some cameras, like the DSI, do not have autoguide outputs. In that case you’ll need Shoestring Astronomy’s GPUSB or GPINT-PT adapters. They provide an ST4 output from your PC, and plug into the laptop’s USB port or a parallel port, respectively. Why is this type of guiding called “ST4,” anyhow? Santa Barbara Instrument Group developed this guide system for use with their ST4 camera.
You can use ST4 guiding only if your mount has an autoguide input port. What if it doesn’t? The popular Meade LX90 and LXD75, for example, do not. That’s harder. Unless the mount manufacturer or somebody else makes some kind of conversion kit or add-on you can forget ST4 guiding. Shoestring does make an ST4 kit for generic (non-go-to) CG5 GEM-style dual axis drives, and Meade used to make the #909 Accessory Module, which could add an ST4 port to the LX90 and LXD75 (apparently the 909 has been discontinued). That does not mean you have to forget autoguiding if there’s no way to add an ST4 input to your mount, though. You can guide through the mount’s serial port instead. In this setup, the computer issues guide commands over the serial line connected to your hand control (usually). This is just like when you are using the laptop to send the mount on go-tos, only instead of telling the mount “go-to M13,” the computer says “move east at guide speed.” What if your PC does not have a serial port (most new laptops do not)? One of the ubiquitous USB – serial converter cables you find in Walmart or BestBuy will work fine for guiding.
Some folks wonder whether it’s OK to use serial guiding. Isn’t ST4 guiding more accurate? Not necessarily. Some mounts and software will be able to use a serial guiding method called “pulse guiding.” This allows the software to not only move the scope in the appropriate direction, but also to change guide speed by small amounts, making for very accurate guiding, easily the equal of ST4. In fact, even non-pulse serial guiding works very well in most cases. Do be aware that if you need/want to use serial guiding, you’ll probably need another program in addition to your guiding software—ASCOM (free). Generally, most guide-software makers do not include built- in drivers that allow your PC to talk serial to your particular mount; they use ASCOM instead.
One other very important thing? If you are guiding through ASCOM, remember, you do NOT plug the serial cable into the Autoguide port. Lots of folks want to do that—where else would you hook-up to the mount for guiding? A serial cable from the computer ONLY goes to a serial port on the mount. Only if you are NOT using ASCOM, only if you have a Shoestring Adapter or a camera with a built-in guide output, do you plug a cable (an ST4 format cable; Shoestring sells ‘em) into the autoguide port on the mount.
Software Set Up
With all the cables connected, only one (important) preliminary step remains, setting up the software. The instructions that follow are aimed mostly at PHD users, but other software is remarkably similar. Software configuration is relatively simple and mainly involves telling the program how you are going to guide and (if you are using serial guiding) what kind of scope/mount you are using. In PHD, you set up for serial guiding by clicking “ASCOM” in the “Mount” menu at the top of the screen. That done, click on the little telescope icon at the bottom of the screen to bring up ASCOM’s familiar telescope chooser. Select your scope type and fill in its details with the “properties” button.
What about them other choices on the Mount menu? GPUSB and GPINT? They allow you to guide through one of the aforementioned Shoestring guiding adapters if your camera does not have an ST4 output. Note that there are multiple selections for the parallel port (GPINT) adapter: GPINT-378, for example. The numbers refer to the address of your particular parallel port. This can be determined using the Device Manager in Windows. Take a look at the Properties for your parallel port and examine its “Resources.” If that sounds confusing, Shoestring Astronomy has a little (free) utility that will find out what your number is. The last choice on the menu, “On Camera,” is, natch, for you lucky folks who have an ST4 output built into your camera. If you are using any of these guide methods you do not and cannot choose your scope type. That info is not required.
Once all them cotton-pickin’ cables and menu selections is sorted, the next step is getting the guidescope focused. If you have not already done so, click the Camera icon in PHD and choose your camera. Pick an exposure too. How long? To begin with, fairly long, at least several seconds depending on the sensitivity of your camera. It is likely the guidescope will be way out of focus. To begin, click the “Loop” icon at the bottom of the PHD window, and watch the display. What do you focus on? If you’re using a go-to scope, the last alignment star will work just fine. Focus until this bright star is as small as possible on the PHD video display. When it is, observe other stars in the frame, increasing exposure a bit if necessary. Make the dimmer ones as small as you can as well. With PHD and most other guide software, it is not necessary to achieve perfect focus; just make the stars as small as you can by eye. When you’re done focusin’ press the Stop icon. Send your go-to scope to the night’s first target, or push a non-go-to one there, and get your imaging camera arranged.
When you are ready to begin guiding, hit the Loop button again. Exposure should be no longer than two seconds if at all possible. If your mount is not precisely polar aligned, and/or has significant Periodic Error, keeping the guide exposures, and thus the guide updates to the mount, short will help keep you on track. Now, examine the display for a reasonably bright star. If one is not found, you may have to adjust the aim of the guidescope (or the whole rig if need be). Only increase exposure if you can’t find a decent guidestar without moving the imaging camera off target. Remember, this star does not need to look like Sirius; it just needs to be obvious to your eye that it is a star. One caveat: make sure this star is not close to the edge of the frame.
When you have a good guidestar candidate, press Stop and then click on the star. When you are ready to begin guiding, press the archery-target icon on PHD. The program, like all other guide software, will then do a calibration; it will move the mount in all four directions (assuming you have declination guiding enabled) to see how the star moves on the guide camera chip. That is why you must not choose a guidestar at the edge of the frame—if calibration moves slide it out of the frame, calibration will, naturally, fail. Don’t be impatient; calibration can take a goodly while with PHD. If all has gone well, calibration will finish without any kind of error, and PHD will begin guiding without any further input from you. There will be a small box around the star, and the program will keep the guidestar in that box (you’ll see changin’ numbers at the bottom of the screen indicating guide corrections). If it looks as if ever’thing is as should be, take an exposure with the imaging camera of the duration you intend to use for subframes. Examine the resulting image carefully. Stars (those at the frame center, at least) nice and round? Success!
What then? Shoot your target. When you are done, press Stop on PHD before moving to the next target, otherwise PHD will make unhappy sounds because its guidestar has been lost. The same thing will happen if the wind blows the scope off target or your buddy, Goober, comes up and taps on the tube: “Wut’s this here camera, Unk Rod?” Chances are, though, that all will go well. Autoguiding is a fairly complex process, but PHD is about as bullet-proof a piece of software as I have ever seen. What if all your stars look like eggs, though? Here are a few tips to get you over the rough spots:
- Balance, balance, balance! This is probably the number one cause of poor autoguiding. Always balance the scope so that it is slightly heavy to the east, so the drive gears pull the scope along. That ensures the main drive gears stay closely engaged and lessens the magnitude of hiccups.
- Start small. When you are first learning to guide, begin with a 1000mm focal length imaging scope or less. You will cry far fewer salty tears than you will if you start out with a C14 at f/11!
- If your stars don’t look great, calibrate. A good calibration is the path to good performance, and one calibration will likely not last all night long. Some programs, like CCDOPS, insist you either enter the declination of each new guidestar or perform a new calibration (I generally have best results by doing a new calibration). PHD does not ask for this, but it does want a new calibration if you move from one side of the Local Meridian to the other.
- If nothing else works, you may have to adjust “advanced settings.” In PHD, clicking the Brain icon brings up a list of cryptic stuff like “aggressiveness,” “RA hysteris,” “Dec algorithm,” and “Calibration step.” In my experience, the only one you may need to fool with in PHD is “Calibration step.” If your candidate guidestar is far from the celestial equator, you may need to increase this value.
- I’m frequently asked whether it is a good idea to do a PEC, “Periodic Error Correction,” recording on the mount (if it has this feature) before attempting to autoguide? The answer is probably not. In some cases a PEC recording and an autoguider actually seem to work against each other. Most guide setups can take care of a mount’s periodic error without any additional help anyway. I will say I have seen a few telescopes—mainly large aperture fork mount SCTs—that simply could not be made to autoguide without doing a PEC recording first to bring down egregiously large RA excursions.
Does this sound like a lot of work? It is, I reckon, but once you get the hang of it it’s easy and adds just a few more steps to your imaging routine. It is gull-derned worth it, too, as you’ll agree when you see all them nicely guided subframes begin to roll out of your imaging camera. Is it always as simple as Push Here Dummy? Usually it is, whether you are using PHD or some other program. Naturally, in this here blog I could only draw the vaguest of outlines of the difficulties you can potentially face; if you do run into problems, as always, thank god for the Internet. There’s a Yahoogroup devoted solely to autoguiding issues, Autoguiding. All the guide software I am aware of has good online support. Go here for the group devoted to Stark Labs software (PHD).
I just wish I could get out and give my autoguiding setup a workout. We got through Gustav with only copious rain (9-inches on Selma street…or was that the River Selma?), but we are now cautiously watching bad, ol’ Hurricane Ike. I keep telling myself this too shall pass, that clear skies and calm are coming. Am I a cockeyed optimist? Stay tuned.