Sunday, October 19, 2014
My Favorite Star Parties: Peach State Star Gaze 2002
This, muchachos, is another installment of this series in which “favorite” don’t mean “best.” Not regarding the skies or facilities of Peach State ’02. Those things were just middlin’. What made this one a winner was, to start with, the people of the Atlanta Astronomy Club (AAC). Add to that some great speakers, and you have a star party that is still one of my favorites even though it didn't offer outstanding views or creature comforts.
What impelled Unk to start thinking “Peach State Star Gaze” as August melted into September a dozen years ago? I’d just got my NexStar 11, Big Bertha, a few months before. I’d had her out under a dark sky once thus far, at the 2002 Chiefland Spring Picnic. She’d performed brilliantly there, and I was hungry for more of the views provided by her aperture, tracking, and goto. There was but one fly in the ol’ ointment, y’all. PSSG wasn’t PSSG no more.
For a while, I’d been hearing about dissatisfaction in the AAC ranks, among the hardcore observers anyhow, concerning the original PSSG site near Jackson, Georgia. It was not perfect sky-wise. How could it be, only 50-miles from the Atlanta megalopolis? The sky was not bad, however, and the facilities at Indian Springs State Park were first rate as star parties go.
Yes, the field was small for the large club’s audience, which consisted of not just local amateurs, but of folks from Alabama and Tennessee, too, and was topping 300. There was sufficient field space and overflow space to accommodate everybody, however, and I didn’t think there’d be a growth spurt to TSP levels anytime soon. I put the rumblings of discontent down to the usual sort of give and take that goes on in any big club. I expected to be back at Indian Springs in the fall.
Nope. Afore long, I learned the Peach State Star Gaze was indeed moving to supposedly darker skies for 2002. The event, which would run from October 3 – 6, wouldn’t even be held in Georgia. It would be over the border in Tennessee at a place called “Whitewater Express,” a private outdoor adventure center/camp near Copperhill, Tennessee in the foothills of the Smoky Mountains.
Well, well, well, Tennessee. Two hours farther for me than Jackson. Was I up for the drive? By myself, since Miss Dorothy wouldn’t be able to attend? Given that the site was an unknown quantity, I wasn't sure. However, since the AAC was switching to the new location because they wanted darker skies, I figgered the star party would feature good observing if nothing else. Anyhow, I was all het up to get Bertha out and didn't want to wait for the semi-dark skies of the Deep South Regional Star Gaze (still held in McComb, Mississippi in them days). I’d give Whitewater a try. Once.
Come Thursday morning, 3 October, I packed my old 1996 Toyota Camry to the gills with Bertha and all the support gear I’d need for three days under the stars and headed north on cotton-picking I-65. With me was the NS11 GPS in her enormous case. The eyepiece case and equipment boxes. A (minimalist) tailgating canopy. Cupla jumpstart batteries. Table, chairs, ice chest, and sleeping bag. You get the picture. Cramming all the stuff in the car was actually easy compared to doing the same—plus more—the previous year for the Texas Star Party, howsomeever.
|Those fried chicken biscuits ain't gonna eat themselves...|
The drive? It wasn’t the length of it that bothered me; it was getting through Atlanta. I married an Atlanta girl, so I’d been to the city many a time, but I’d never made the drive by myself. In the days before GPS, all them Interstate entrances and exits in Atlanta dang sure game me the willies.
I only made a couple of stops; one at the Montgomery Stuckey’s for my traditional fried chicken biscuit, and one just over the Georgia line for gas. I was trying my dangdest to miss the Atlanta lunchtime traffic and the beginning of rush hour (which starts real early in the big city). My hands were a little sweaty on the wheel, but I successfully negotiated I-85, got on I-75, and made it to I-575, which would take me close to the site.
Once past Hot ‘Lanta, I could relax for a while, ‘til it was time to get off the Interstates and find Whitewater Express with the help of the somewhat vague instructions I’d printed out. I had a rather entertaining book on tape (really on a tape back then) to listen to, Peter Straub’s The Hellfire Club, whose somehow likable serial killer antagonist almost steals the novel from the strong but put-upon female hero. I was just zippng along, since even Georgia 5, which I picked up after I-575, was a four-laner for most of its length.
Highway 5 did eventually degenerate into 2-lanes, and this last part of the journey was different both from the way I’d imagined it and from what the directions seemed to describe. Unk, being the perceptive sort of cat he is, figgered he must have taken a wrong turn about the time he passed a huge sign reading “Welcome to North Carolina.” I turned around, found the missed turn a few miles back, and was soon entering Whitewater Express’ grounds. I stopped at the Registration Tent, got my packet and T-shirt, and headed for the field.
My first task was finding a spot on the large but crowded observing field. Me and the Camry orbited, and we orbited, and we orbited, finally finding a place near the center. Stopped, got out, stretched my legs and took stock.
I was impressed with Whitewater Express, at least as far as the scenery went. Fir trees and hills that could almost qualify as small mountains ringed the field. In the far-off distance were the Great Smokies. The place bordered the Ocoee River, and, as its name implied, featured white water rafting during the summer. In the autumn, Whitewater got by with the occasional church group before the coming of the Atlanta Astronomy Club.
First order of bidness was gear set up. A little over a decade ago, I was younger and stronger and Bertha was reasonably easy to manage. Unlike today, when she has somehow put on enough weight (sorry, old girl) that broken down old Unk is plotting to move her OTA to a GEM. The tent canopy, just a tarp with some ropes and poles back then, went up. Observing table and chairs and equipment boxes went under that, and I was done.
Now it was time to seek out the little astronomer’s room and have a look at the rest of Whitewater Express. First, I dropped my sleeping bag off in my cabin, which was not too far from the field. The little log cabin I had been assigned was something of a paradox. It was attractive on the outside and looked nearly new. Inside, however, it was purty doggone Spartan.
The bunks were, no exaggeration, more like wooden shelves than beds. There were three tiers of ‘em, and while they had mattresses, it would have been a challenge to find thinner ones. There were a lot of bunks in that tiny cabin. What there wasn’t was heat or AC. I didn’t think we’d need heat, since it was on the sticky and humid side. I just hoped it wouldn’t get hot enough to make me wish for air-conditioning.
The bathhouse and toilets nearest my cabin were in the same large building as the dining hall. Said chow hall was new looking and expansive. Only problem Unk foresaw? The dining area was open to the elements. That was fine during Whitewater’s peak season, the summer. In the fall in the mountains? Not so much. If it got even a little cooler than the predicted late afternoon 70s – upper 60s, that could be a freaking problem.
|Unk's modest setup...|
I was later to learn I had lucked out. Apparently, my accommodations were several clicks nicer than those some of the other folks had to deal with. From what I heard, some of the other facilities on the site were akin to the infamous Black Hole of Calcutta at TSP ’97.
What was up next was supper. And it was not bad, not bad at all. I found the grub at Whitewater quite passable. On the first evening, it was simple but OK spaghetti, garlic bread, and salad. There was enough of it and I enjoyed shooting the breeze with my fellow diners, who included Sky & Telescope Editor Kelly Beatty, keynote speaker David Levy, and celestial cartographer par excellence, Wil Tirion. I always enjoyed hanging out with Kelly, and David’s not just a great speaker and observer; he’s a lot of fun to be around.
So, supper was real fun. But, like you, I go to a star party, most of all, for observing. What were the skies doing? Nothing good. You’d think that up in the hills of Tennessee dadgum hurricanes wouldn’t be a problem. But one was, a bad girl named “Lili.” Bands of clouds from this weak late-season storm had followed me all the freaking way from the Gulf Coast and were making their presence felt.
I did get Bertha uncovered and aligned, and saw a few things along the summer Milky Way, including a cool nebula in Cygnus new to me that astro-writer and AAC member Rich Jakiel pointed out. But mostly it was touch and go, with clear stretches becoming fewer and fewer. By ten p.m., even the sucker holes were filling in with haze, and the bands of drifting clouds began to put on the brakes.
All too soon, the evil gray things were aided and abetted by thick fog rolling in out of the hills, and I knew Bertha and I were done for Thursday night. Once my girl was tucked in, I spent some time shooting the breeze with old friends, who, in addition to my fellow club members from the PSAS, George Byron, Marvin Uphaus, and Betsy Hopson, included Auburn Astronomical Society stalwarts Russell Whigham and Eddie Kirkland.
|My (log) cabin...|
What else did I do? I was tired but not sleepy and spent quite a spell sitting under my canopy hoping for one more break in the clouds. When that had not come by midnight, I broke out the Rebel Yell and relaxed, till the fog had just about soaked me to the skin and I trundled off to my hard wooden bunk and my sleeping bag for some welcome shuteye. After I helped poor old George, who had severe back and neck problems, climb into his tier-three bunk. I offered let him have my bottom bunk, but, in typical George fashion, he’d have none of it.
Friday morning was a slow one and so was the rest of the day. The bathroom’s showers turned out to be OK. Having to trot to a bathroom across the street is not like staying in a motel, but the facilities were clean enough. Breakfast, like supper the night before, was plain and institutional but adequate. Unfortunately, the Whitewater folks insisted on serving it at 8 in the freaking a.m. Even given that there was to be a paucity of late night observing in 2002, that was too early for a star party breakfast.
The weather, unfortunately, did not inspire confidence. There were some surprisingly strong wind gusts, no doubt caused by what was left of Lili, beginning in the morning and continuing well into the afternoon. Amazingly, my flimsy tent canopy somehow remained standing. That was the good. The bad was that by afternoon it was fraking raining. What was there to do on a rainy star party day? Listen to speakers and buy cool astro-stuff.
The speaker roster for PSSG ought-two was a very fine one. David Levy spoke on Friday as well as Saturday. He was preceded on Friday by Wil Tirion, who talked about his famous atlases including Sky Atlas 2000. Wil was supposed to have been the keynote speaker at PSSG 2001, but the events of 9/11, just a couple of days before, prevented him from flying in. It was a treat to hear the man who composed the atlas I’d used for so many years explain how it and his even deeper work, Uranometria 2000, had been created—in the days when you didn’t just sit down at a computer and mash “print.”
|These little guys seem to follow me everywhere...|
David Levy is my generation’s Walter Scott Houston or maybe Leslie Peltier, and even a casual afternoon talk by the man is something you don’t want to miss. The only bringdown concerning David was that, naturally, all the star partiers wanted to hear him, and the presentation hall at Whitewater was way too small. Much smaller than Indian Springs’ main building. The many folks who couldn’t get in stood outside at the windows despite rain showers that came and went, trying to hear what David was saying, not a very satisfactory solution. It was also stiflingly hot in the hall, which, like everything else at Whitewater, was not air-conditioned.
Which brings us to one of Unk’s fave parts of star party attendance, buyin’ that dadgum astro-stuff. There was a decent if not overwhelming lineup of vendors in a small building on the edge of the observing field. There was Chuck Pisa, then with Wolf Camera, Ken Dauzat’s Ken’s Rings and Things, Astronomy to Go, and a couple of smaller outfits besides. One of those smaller vendors was Thomas Bopp of Comet Hale Bopp fame, who was selling posters and pictures of “his” Great Comet.
My buy? I’d just learned Lumicon had closed its doors, and I was anxious to get one of their 2-inch UHC filters while I could, so I turned over some bucks to Chuck. Turned out I needn’t have worried; Lumicon was kept going under new management. Nevertheless, the UHC was (and is) a good filter and it was nice to have it for the star party.
I didn’t buy anything from Ken, but enjoyed spending some time with my old friend and his wife, Karen. I was actually surprised to see them there with their array of custom-made mounting rings and other accessories—Louisiana had been right in the path of Hurricane Lili. Health problems have since impelled Ken to shut down his pioneering Internet astronomy store, but he made a whole lot of folks, including Unk, happy with his plain but functional accessories over the years.
The vendors’ hall didn’t just offer astro-goodies, but also real goodies. After sundown, there was plenty of hot coffee and deliciously sugar-laden treats like little Debbie cakes on sale all night long. That was an old tradition from the Indian Springs days, and I was right happy it was continuing.
|Dining hall and bathhouse...|
Sometimes I do get lucky. At sundown, the doggone clouds were beginning to scamper off, and it was obvious we were gonna get in a little viewing. You could almost hear the folks on the field heave a collective sigh of relief. It had begun to look like we might be approaching the outskirts of the dreaded Skunk City.
Once Sol was out of the way, I was able to give Whitewater Express’ sky a better evaluation than I had Thursday. The verdict? The site was okay, if not really much better than Indian Springs. There was a substantial light-dome in the west, from Chattanooga. Surprisingly, there was also a smaller one to the south, from Atlanta 100 miles away, I presumed. The light pollution was undoubtedly made worse by the higher than normal humidity, but there was no doubt in Unk's formerly military mind the light dome from Chattanooga, at least, would have been prominent even under better conditions.
The forecast for Friday night was far from perfect—“mostly cloudy”—and that turned out to be mostly correct. That didn’t stop your old Uncle, however. Thanks to Bertha’s faultless goto, I was able to observe thirty objects before my run was ended after about two hours by another batch of clouds. Before that happened, I snagged quite a few of the elusive nebulae scattered through Cassiopeia and Cepheus, which showed up well with my nice new Lumicon filter. With my old 35mm 82-degree Bird’s Eye eyepiece (which I got from Cousin Herb York), Bertha was almost a wide field scope.
One thing was sure, the telescope performed admirably despite a small glitch. When pointed west, Bertha would occasionally suffer from a small “jump” in tracking. That affected all the early NexStar GPS scopes, and was only cured by a firmware update, which I got some time after the star party. The jump didn’t come close to spoiling my views, however.
When the clouds moved in, they did so with a vengeance and there was just no question about there being any further viewing Friday. Out came the Yell, and Unk spend the remaining hours of his Friday evening wandering around the big field annoying all and sundry.
|The weather looked this way much of the time Saturday...|
Saturday evening brought one last meal in a dining hall, that, as I expected, was on the chilly side after the humidity and temperature dropped a hair in late afternoon. The day had been spent much as Friday had been, trotting around the field looking at folks’ gear and listening to speakers. In addition to David’s Keynote, given to another SRO audience, there was Kelly Beatty’s interesting (or maybe scary) presentation on the threat posed by near Earth asteroids. And an excellent talk by Rich Jakiel on deep-sky-fuzzy hunting.
Saturday night’s skies were looking to be the best of the event, which was a bummer since I knew I’d want to shut down early to prepare for the drive home. Transparency was never much better than “acceptable,” but Bertha and I saw a lot, especially of the legendary clusters and nebulae scattered up and down the spine of Cygnus the Swan. I’d take an occasional break for coffee (and, yes, I’ll admit it, Little Debbies) in those benighted pre-Monster Energy Drink days, but I didn’t take too many breaks, since midnight was my designated turns-into-a-pumpkin time. Total for the evening was another thirty objects, making my final catch for the event 75, not bad given the conditions.
And that was that. While the clouds stayed away ‘til about 3 a.m., I was snoozing by then. Sunday morning, I was southbound as early as possible and even managed to find the turn off for I-85 in dadgum Atlanta—I’d been pretty sure I’d miss it and wind up somewhere in the Okefenokee Swamp.
I had a good time at the Tennessee edition of the PSSG, but I never went back. Just too many miles compared to Chiefland or DSRSG for skies that were not much—if any—better than what I had closer to home. I was sorry to give up star partying with my Atlanta friends, but in those go-go days of my engineering career, a six-hour drive was better than an eight-hour one.
Whatever happened to Whitewater Express? A Google search shows it to still be in business, but it continues without Peach State. The star party stayed there for a few years, but, apparently, other members of the PSSG’s audience began to feel the same way about the place that I had. The star party was moved again to the darker (Georgia) location where it is today, the Deer Lick Astronomy Village.
I hope to get back to the big Georgia star party some day if I can just get up the gumption to do an event where I can’t stay in a motel (Deer Lick is out in the boondocks). It’s not easy for your ever older and more decrepit Uncle to convince himself to do that, but I do miss my PSSG friends and dang sure intend to join them for another Peach State one of these years, muchachos.
Next Time: Back to Feliciana...
Sunday, October 12, 2014
The IBM GEM
“What the hail is Uncle Rod goin' on about now?” The GEM, the German equatorial mount, I am referring to, muchachos, is the time-honored Synta (SkyWatcher) EQ6 (a.k.a. Orion Atlas). It is both an amateur astronomy classic and, best of all, an affordable classic. “OK, Unk, but where does the IBM business come in?”
The EQ6, which has been a fixture of amateur astronomy for over a decade, is much like the original IBM PC and its clones. It is out there in large numbers, is simple but reliable and long-lived, and, because of those things, there are tons of aftermarket accessories and add-ons for it. Countless observers and imagers use it; in Europe and the UK, it’s unusual to find an astrophotographer not using an EQ6.
Not that the EQ6 got off to a roaring start. The original non-goto version of the mount showed promise, but that was about it. When I saw my first example of this Chinese mount right after the turn of the century, I was impressed by its heft and appearance. Its large equatorial head weighed over 40 pounds, and its design style was an obvious “homage” to Takashashi, if not even in the same Solar System when it came to fit and finish.
Yeah, it soon became evident that the EQ6 was no Takahashi, and not just because it was cast, and somewhat roughly cast (there's plenty of casting rather than machining on the Tak mounts, too). Its performance was also nothing like that of the EM-400 that inspired it. It didn’t track very well. The periodic error inherent in its gears was large and not overly smooth. Oh, you could take long exposure deep sky images with the mount, but not easily. You’d be throwing out a lot of frames due to trailed stars, even if you were auto guiding the mount.
Surprisingly for some of us, Synta, who was becoming the 800-pound gorilla of the bargain astro-biz, didn’t leave the EQ6 as it was. They soon brought forth a new model, a goto version of the EQ6, variously referred to as the “SynTrek,” “SynScan,” and “GT” version. Not only did this thing have a computer hand control, the SynScan, it had, we were told, had its gears and motors replaced with more imaging-friendly ones.
That was all right nice, but Unk wasn’t interested, even at the very reasonable price Orion wanted for the goto version, 1400 dineros. I already had a goto GEM, a CG5, that worked adequately well for my modest requirements. Or it did ‘til one windy night Down Chiefland Way.
Unk’s EQ6 story really begins back in April of 2006, when I was at the Chiefland Astronomy Village for the vaunted Spring Picnic. The skies were not great; they were hazier than I’d have liked. But they were not that bad, either. What was bad? The pea-picking wind. Despite the haze and occasional clouds, I was seeing a lot with the combo of my C8, Celeste, and my old Stellacam 2 deep sky video camera. Or I would have been seeing a lot if the CG5 mount hadn’t trembled like a sinner in the hands of Elmer Gantry with every wind gust.
|Could be a comet, could be a custard pie...|
I wasn’t happy despite the fact that by keeping the camera rolling I got some nice pictures, including some good footage of pretty little Comet Schwassmann–Wachmann. It wasn’t easy getting those shots, and most of my footage looked like the image here. I followed my friend Pat Rochford’s suggestion, and removed the dew shield from Celeste, which helped some, but not enough. It was clear what I needed: a sturdier GEM mount.
The CG5 was fine for video most of the time, but obviously not all the time. It also did well enough for Unk’s undemanding prime focus deep sky imaging, but it would have been nice to have a mount that delivered a larger proportion of good frames than the CG5 could. Of course, once Unk resolved, some months after that Spring Picnic, to think “new mount,” came the hard part. Which one?
I was awfully tempted (and still am) by Losmandy’s G11. It was several steps up from the CG5, to say the least. But, given the relatively few astrophotography worthy nights we get down in the Swamp, I wasn’t convinced I needed to spend even the relatively modest amount the G11 commanded, about 3K. Not when I might be able to get by for half that. I’d been hearing a lot of good things about the Atlas/EQ6, and began turning in that direction.
Unk being Unk, it took me months to screw my courage to the sticking point and give my credit card number to Orion, the sole U.S. seller of the EQ6. What pushed me over the edge were two things. First, the Atlas’ hand control, the SynScan, was similar to the Celestron NexStar HC. There were plenty of differences, I knew, but I’d still be on relatively familiar ground.
Secondly, there was a program for the Atlas that was a lot like my beloved NexRemote, which allows the Celestron mounts to be operated with a computer sans hand control. EQMOD for the SynScan mounts was like NexRemote, and had even more features.
The only question remaining concerned the “Hand control or no hand control?” option Orion allowed you to exercise seven years ago. Despite Unk’s famous tendency towards thrift (stinginess, that is), I decided to get the HC. There’d surely be times when I wouldn’t want to tote a PC along to run EQMOD. That turned out to be true and, as you’ll hear, as the SynScan firmware has continued to mature, the more I’ve found myself using the HC.
Due to the Swamp’s horrendous weather in the fall of 2007, the Atlas, which I’d received in October, didn't get its first serious night under the stars until January of ’08. And when it did get that night, I used EQMOD exclusively. You can read the whole story in this entry, but I will say here that I am still amazed at my good results despite plenty of fumbling.
Setting up on the Chiefland Astronomy Village field on a surprisingly chilly January Florida night, I was skittish. Mostly about one thing. The SynScan HC at this time did not include a built in polar alignment routine. Neither did EQMOD. You polar aligned the Atlas the old-fashioned way, with a polar scope. Visions of dim polar scopes and poor polar alignments danced in Unk’s post-Christmas-letdown head.
I needn't have worried. The EQ6 has one of the best polar borescopes in the business. No, it’s not as good as the legendary Takahashi polar scope, but till the coming of the iOptron polar alignment scopes, it was at least second best with a legible, illuminated reticle and, unusual for imported polar scopes, a halfway decent apparent field of view.
Polar aligned, I goto aligned by syncing on a few, and only a few, stars with EQMOD and the planetarium program I used in them days, Cartes du Ciel. On that first night, any target I requested anywhere in the sky was somewhere in the field of the C8 when the slews stopped. On my second night in Chiefland, the mount delivered round stars in three and four minute (guided) subframes without complaint.
Otherwise? This was one big sucka. The Atlas’ equatorial head literally dwarfed my friend Carl’s Celestron CGE. Not that that was all to the good. The weight of the mount, 40-pounds plus for the head alone, was to often impel lazy old Unk to use the CG5 instead. Its heft was undeniably impressive though. And so was its slewing. The Atlas uses stepper motors rather than the CG5's servos and is about a million times quieter.
How about that hand control? The few times I tried it in those early days, I was not impressed. So-so gotos at best, and very few features compared to the NexStar HC. It wasn’t just the polar alignment routine that was missing, but even the ability to goto an inputted RA and declination—you had to enter your comet or whatever as a “user object.” Not hard, but it would have been easier just to punch in RA and dec numbers.
One thing I did like about the SynScan was its Polaris H.A. readout. Once you entered the time, date, and site information, the HC would display the current Polaris hour angle. You could then use that in conjunction with the right ascension setting circle to get a more accurate polar alignment with the polar scope. Mucho bettero than what was obtainable by merely matching the constellation pattern on the reticle to the constellations in the sky.
I continued to use the Atlas with EQMOD, if not that frequently. Let’s face it: it was just easier to transport and set up the CG5 for deep sky video. About the only time the Atlas got used was when Unk wanted to do DSLR imaging, which, by the end of the last decade, had entirely replaced CCDing in his affections. I’d probably have used the Atlas more if I could have left the computer at home, however.
There were plenty of nights that would have been Atlas nights at the Possum Swamp Astronomical Society Dark Site if I could have run just with the SynScan. Those nights that were windy enough to challenge the CG5, but which were not quite clear enough to make me want tote laptop, laptop battery, wireless gamepad, wireless gamepad receiver, USB hub, and all the other junk needed for an EQMOD run.
There things remained for a long while, ‘til 2012 to be exact. That was the year Synta really buckled down with the SynScan firmware. Oh, they’d continued to update it in the four years I’d owned the mount, but the updates were incremental and didn’t contain many new features. Certainly nothing like the big Celestron GEM firmware update of 2008.
Then, everything changed. In 2012 Synta/SkyWatcher issued the beta release of an update that contained lots of new stuff, including a polar alignment routine identical to the AllStar of the company’s NexStar mounts, something everybody was raving about. I gave the new firmware a good check ride in September of that year, and found the beta was mostly all there, if still containing a few rough edges.
The polar alignment routine worked, and the goto alignment had been improved. The star choices the HC offered during alignment were more likely to produce good goto accuracy than formerly. Before the new firmware, if you just accepted the first three stars the HC picked, you were almost guaranteed poor goto performance.
The current firmware release for SynScan v3.35, has mostly rounded off all the rough edges I discovered at the CAV that September of 2012. It’s still maybe not quite perfect, but a new SynScan firmware release is, I understand, in the offing, and I believe it will finally tie the bow on the SynScan hand controller package.
It wasn’t just the new firmware that helped with the hand control’s accuracy. What probably improved it most was that four years down the line Unk finally read the manual’s instructions regarding the HC alignment. Before, I’d tended to use the SynScan just like the NexStar, accepting whichever stars it first offered. As above, that led to fair goto accuracy at best. One day I was looking up something else in the manual, however, and noticed there were rules for alignment star choice.
According to the instructions, the first two stars should be separated by at least three hours of right ascension. Separation in azimuth was not as important, especially with a decent polar alignment. Star three, the book said, should be between declinations 30 and 70, north or south…
Hmmm…why not give it a try? Sure would be nice to get the HC working reliably. I hauled the mount out to the dark site, did a three star alignment, rejecting stars the HC offered that did not follow the above rules, and started gotoing my gotos. Guess what? The mount never missed a beat with the C8. Ever’thing was in a wide-field 12mm eyepiece. The new firmware, as I found out in Chiefland, had refined the hand control’s ability to choose “good” stars, but I am still careful to monitor the choices, and doing that still seems to help with accuracy.
Sometimes you can’t choose good stars, however. The mount does not like alignment stars that are too high in the sky, too close to the Meridian, that is. But sometimes you’ve got no choice. A tree (whose days are numbered) blocks the southeast sky at the New Manse, so I have to use the stars I can see. Nevertheless, on a recent DSLR run from the backyard, the mount placed anything I requested in the field of my Canon 60D with the C8 at f/6.3.
|Starry Night Pro Plus and EQMOD...|
The upshot of all these things is that I am now using the SynScan hand control more than EQMOD. That may change as I become more comfortable with the new planetarium program I am now using, Starry Night Pro Plus 6 (yes, Skeezix, I know it’ not new, but it’s new to me for reasons you will read about some Sunday soon). I will undoubtedly go back to EQMOD for some imaging runs, but it’s nice to know that I don’t have to use EQMOD if I don’t feel like using it.
So you’ve got your Atlas EQ6. It works good. But you’ve got the sneaking suspicion that it could be More Better Gooder. There are things that can make the mount better. A sturdier tripod is one—the 2-inch steel-legged tripod that ships with the Atlas is not bad, but there is little doubt it is the weak link for this heavy mount.
There are a couple of ways to solve the tripod conundrum. The obvious way to do that is by replacing the sucka. While I don’t know of a replacement tripod being manufactured specifically for the EQ6, you can buy adapters that can let you use better tripods. My CAV buddy Paul Lavoie, mounted his CGEM, which is similar to the Atlas, on the large Meade field tripod (the one for the 12-inch SCT), and you could do that same for your EQ6. It does make a difference.
Want an off the shelf solution? Mount guru Ed Thomas sells the famous Berlebach tripods configured for the Atlas through his company, Deep Space Products. They do NOT come cheap, but the results will most assuredly be better than the stock tripod and they will also most assuredly lend your mount that touch of class.
If, like Unk, the Berelebachs are a mite too rich for your blood, there is another way. Maybe not quite as effective a way, but close. The problem with the Atlas tripod is not really the tripod legs, or at least not just the tripod legs. It’s that pitiful little spreader. A tripod spreader should be a sturdy thing that doesn't just provide you with a place to stow eyepieces, but something that holds the legs firmly apart and stabilizes the tripod, which the Atlas’ puny cast spreader cannot do.
For once, campers, the fix is easy. It comes from an outfit called “TPI,” Telescope Performance Improvements. Their beautiful (and strong) spreader attaches to the lower ends of the stock tripod legs and holds them firmly apart. It folds easily for transport and does not make a nuisance of itself, either.
You can kick it up another notch with one of TPI’s big accessory trays that clamp to their spreader. Install one, put your jump-start battery on that, and your rig is even more stable (we used to hang gallon milk jugs full of water from our tripod heads to stablize ‘em). While your tripod still won’t look like a Berlebach, it will be near about as steady, and the TPI gear also makes the old tripod look much nicer—almost gives it that touch of mink. The damage? About $350.00, which is a freaking bargain if you’re trying to get the mount to accommodate a heavy OTA or are going after long exposures at longer focal lengths.
If you just want to keep it steady for imaging with a C8 or a small medium refractor? I still recommend either the TPI spreader or one of Ed’s tripods, but if you are as cheap as Unk, you might be able to get by with a set of Celestron’s vibration suppression pads for about 40 bucks from Unk’s fave photography superstore, B&H.
What can you do to help the mount itself, assuming your OTAs are larger than Unk’s C8 or your imaging goals more lofty? Have a stroll through the web pages of ADM. They have several products that can improve your mount, but the big deal is a replacement saddle that will allow your EQ6 to use OTAs with Losmandy D dovetails rather than Vixen dovetails. There is no question the Losmandy dovetail setup makes for a steadier scope once you get past a C8 or a C102.
What else can help with that C11 or Meade 12? A longer, stronger counterweight shaft. Orion and others will sell you a replacement shaft that will allow your heavy OTA to balance with fewer/lighter weights. Do keep in mind that these solutions will mean giving up the Atlas’ convenient retractable counterweight shaft feature.
“That’s all cool, Unk, but it ain’t what I had in mind. What I am thinking about is HYPERTUNING the doggone thing.” Some folks do dig into their mounts, replacing everything from gears to grease in order to (try to) improve their EQ6s’ performance. This “hypertuning” can include not just regreasing, but polishing of various parts, remeshing gears, replacing some parts, and modifying the Atlas somewhat creaky altitude and azimuth adjuster system (if you can call it that).
Should you? I am inclined to say, “no.” It’s too easy to mess something up bad unless you are considerably more mechanically inclined than Unk. If you think your mount needs a rework, let Ed Thomas do it instead. He will do it right. However, as he will tell you, hypertuning will not turn your mount into a Tak or an A-P. It can help the mount live up to its potential, but if you need an A-P mount, buy an A-P mount. Luckily for our bank accounts, most of us don’t need one.
And that, muchachos, is purty much the Atlas story till now. Should you get one or wait for the next big thing outa China? As always in amateur astronomy, “that depends”—on you, your resources, and your goals. But the Atlas is a solid, time-tested, uber dependable mount. It ought to tell you something that Synta, despite introducing the newer and “better” including the CGEM and the AZ-EQ6, continues to pump out the old reliable. That’s because it is the old reliable. Recommended, y’all.
Next Time: I'm rearranging the schedule...to get y'all in the mood for the fall star party season, let's go to the 2002 Peach State Star Gaze!
Sunday, October 05, 2014
The Refractor Way Part II: Imaging with a Small APO
“’Twas a dark and stormy night.” Not really, muchachos. In fact, the last dark of the Moon Saturday evening was one of the best we've seen in the swamp in a long, long time. Damp, sure, but reasonably cool. Some autumn-like haze on the horizons, but clear 30-degrees up with nice, steady seeing.
As always, though, your old Uncle is putting the doggone cart before the horse. Let’s start at the beginning, shall we? I had several goals for my Saturday night expedition to the Possum Swamp Astronomical Society Dark Site. Firstly, I needed some images, both for a magazine assignment I am working on and for use with my “Uncle Rod’s Messier Album” series here.
I also wanted to do the observing for Part II of “The Refractor Way,” which I began last week. The second installment would concern imaging with a small APO refractor, and, ergo, I needed to do some imaging with a small APO refractor.
Lastly, I wanted to check out a “new” piece of gear, Hotech’s SCA field flattener, which is designed for f/5 to f/8 refractors. While the evening’s scope, the Megrez 80, Veronica, has a moderate f/7 focal ratio and a relatively flat field, she is not perfect in that regard, and I was interested to see what the SCA could do for her. While I received the flattener last fall, the weather, other projects, and our move to the New Manse had prevented me from doing pea-turkey with it.
Come 5 p.m., I loaded up the 4Runner, Miss Van Pelt. Which was not hard to do. I’d only be on site for a few hours, so I didn't need the EZ Up canopy—I’d work out of the back of the 4Runner. Wasn't doing video, so I didn't need a monitor or a DVR. What I packed was the VX GEM mount, the 80mm William Optics Megrez II refractor, “Veronica,” in her case, the Canon 60D DSLR, the Toshiba laptop (for Nebulosity), couple of gear cases, and three jumpstart batteries. One for the DewBuster, one for the mount, and one for the big-screen laptop (via an inverter).
Out at the site, everything was “go” for once. I’d have several buddies with me for the evening, including my old pal Max, who’d be imaging with his 80mm refractor, a Brandon. Most importantly, perhaps, the sky was holding. A couple of my weather resources, including Scope Nights and the dadgum Clear Sky Clock, had been showing a possibility of clouds, but as sunset came on, the few white fluffy things that had been cruising the sky scurried off. Next on your old Uncle’s agenda was setup.
Which was remarkably easy. Plunk down tripod, attach VX mount head and counterweight, place Veronica in the saddle, plug in HC (being careful to get the cord in the right socket less I let the cotton-picking smoke out), hook up battery, rig the DewBuster heater and its battery, install the Intes 2-inch diagonal and reticle eyepiece for alignment, and I was ready to go.
I’d already tested the mount with the Canon 60D and SCA on the scope, so I knew where the declination counterweight needed to go for proper balance (slightly east heavy). Almost all the way up the counterweight shaft, that is. While the Megrez is not a lightweight for an 80mm refractor, she is considerably lighter than the Edge 800. When I get a few pennies saved up, I need to order a 7.5 pound counterweight, which will be more suitable for Veronica and much more suitable for my 66mm APO than the VX’s stock 11-pound weight.
And that was it. No guidescope, no guide camera. Given my experience with unguided imaging with the VX Down Chiefland Way last summer , I was purty sure keeping exposures to a minute or less would, with a reasonable polar alignment, produce round stars with the Megrez's 560mm of focal length. At any rate, I didn’t have a mount for my 50mm Orion mini-guidescope appropriate for Veronica (since rectified), so I’d have to go unguided.
While I normally run the VX with NexRemote, I demurred on this night. I wanted the gear loadout and the cables and the hookup to be as simple and quick as possible. I’d just use the Plus HC that came with the mount. While I still don’t like the new HC as much as I liked the old NexStar hand control, I reckon I’ve made friends with it. I have a perfectly good old-style programmable HC I could use with the VX, but I haven’t yet been moved to do so.
|The Hotech SCA Flattener...|
Anyhoo, all that remained was to wait for Polaris to wink on. When the North Star did so, I centered him in the hollow polar bore of the VX to make AllStar a little quicker. The closer you get to the pole initially, the less you have to move the mount during the hand control's AllStar polar alignment procedure, and the less the need for a redo of the goto alignment afterwards. I sometimes use a polar align helper program, usually one on my iPhone (the free Scope Help these days) to get the R.A. axis as close as possible to the NCP during rough alignment, but I didn’t this time; just centered Polaris is the polar-scope-less R.A. axis bore.
Now, just a little more waiting to give the alignment stars time to peep out. I spent that time admiring Max's Brandon refractor. While it’s an older scope now and could use some updating, like with a modern focuser, it is still a nice telescope. It's not an APO, but its images show little color. The most striking difference between it and the Megrez? The Brandon looks like an 80mm. Sly Veronica often fools folks into thinking she is a 4-inch. At any rate, the images of deep sky objects the two scopes produce are near identical.
The six-star (two alignment stars and four “calibration” stars) goto alignment went smooth as silk, but it really wouldn't be an Uncle Rod observing run if there weren't some kind of a foul-up, now would it? That came during the AllStar polar alignment. The best star to use for the automated polar alignment routine is one due south, not too far from the intersection of the Celestial Equator and Local Meridian. What was over that-a-way? Sagittarius, and I knew one of the Archer’s stars, Nunki, was in the hand control’s “named star” database, so I thought I’d use it as my polar alignment “tool.”
I mashed the buttons to send the mount to Nunki, and when the VX stopped, I peered into the 12mm reticle eyepiece in Miss Veronica’s diagonal. I didn’t look through the Mergrez’s zero power finder, since I had little doubt the star would be in the field of the main eyepiece. Sure enough, Nunki was just off center and shining bright.
Star visible in the eyepiece, I didn't center it; instead, I hit the Align button on the HC and started AllStar from that button’s menu. First thing that happens is that the HC tells you to center the star with the hand control buttons. I did, and the HC reported that it was synced to the star, Nunki. It then slewed away and instructed me to re-center the star with the hand control buttons. I did so, and the mount slewed away one last time. A considerable distance, since the star was no longer in the eyepiece. The HC’s next message told me to center the star one last time using the altitude and azimuth adjusters on the mount, not the buttons. Hokay…
|Zhumell's "Deep Sky" clone...|
So far, so good, till I squinted through the finder. The little bull’s-eye was a long ways from Nunki. I was no doubt a degree or two off the pole, but not what looked to be close to five degrees. I was flummoxed. Should I power down the mount and start over? Then I had an embarrassing epiphany. I had it in my head that Nunki was the “top” star on the lid of the teapot. Was that right? I asked Bubba Taras. He had the same impression, but said maybe we ought to take a look at a chart and fetched his Sky and Telescope Pocket Sky Atlas.
Wheeew! Turned out we was both wrong. Nunki is the brightest star in the teapot’s handle. That being the case, the mount had stopped a reasonable distance from the star. I used the altitude and azimuth adjusters to move the relatively small distance to re-center Nunki and we was done.
As I said up above, if you have to move the mount far during polar alignment, you will need to do a new goto alignment (or replace the alignment stars in the hand control). I essayed a goto to M13 to see how we had fared in that regard. The Great Glob wasn’t quite centered, but it was easily in the somewhat narrow field of the 12mm Meade reticle eyepiece. I decided we could get by without messing with the goto alignment, and spent a couple of minutes just admiring the globular. It wasn’t yet dark, but inserting the 7mm Uwan eyepiece showed good resolution.
It was now camera time. I stowed the diagonal and eyepiece and got the Canon 60D out of my gadget bag. I replaced the 60D’s lens with the combination of a T-adapter ring and the T-threaded SCA flattener, which screws right onto the T-ring. I inserted the whole shebang into the 2-inch extension tube on the Megrez (which is needed for imaging and visual use both). The SCA is particularly cool in this regard. After I inserted it in the extension tube, I turned the SCA's threaded ring, which causes a series of rubber o-like rings to expand, ensuring the flattener is held securely in the drawtube. The nature of this arrangement makes the SCA self-centering, which is critical for good performance.
All that remained of camera setup was connecting the 60D to the laptop via a USB cable and lighting off my camera control program, Nebulosity. When I was done, I was feeling a mite skittish, however. I wasn’t sure whether I’d got the scope properly configured with extension tube, SCA, and T-ring so I could achieve focus. I sent the VX to bright Arcturus and started up Nebulosity to find out.
|M13 (click for larger image)...|
Two things I really like about my setup are the 60D’s Live View feature and Nebulosity’s focus tools. I told y’all all about Neb not long back, so here I’ll just say its focus mode is finer than split frog hair. Mash the “frame and focus” button and Neb displays the field on the big screen of the laptop with images updating in video fashion. That makes it simple to get a bright star as small as possible. And I was able to get Arcturus nice and small. I had to rack the focuser out a ways, but there was sufficient travel.
Rough focus done, I engaged “Fine Focus” and clicked on a dimmer, unsaturated star onscreen. That brings up a small zoomed-in image of the star along with intensity and Half Flux Radius numbers. Make the first number as large as possible and the second as small as possible, and you are focused.
To make sure everything was copacetic, I thought I’d start with a bright target, M13, natch. Slewed back to the globular, engaged Frame and Focus again, this time with 2-second exposures, centered the cluster up a little, and was soon ready to shoot.
I chose to image at ISO 6400. Some folks look askance at DSLRs’ higher ISOs, but my experience is that you capture more detail, especially in less than perfect skies, with higher speeds, and that today’s cameras are remarkably noise free at bigger ISOs. In fact, sometimes DSLRs' higher speeds offer better resolution than lower ones.
I did a 30-second preview, and was pleased with the results. M13 was a mite small, but not too small. At f/7 with the 80mm, we was only at 560mm, considerably shorter than my accustomed 1400 mm with the Edge 800 at f/7. The stars looked excellent to the very frame edge thanks to the Hotech flattener. I probably don’t have it quite at the correct spacing, but the results were still mucho better than without. I will hunt around and see if I can find a short extension ring before the next run to put the camera a little closer to optimum spacing with the flattener. In short, I was thrilled with the Hotech.
Time to get started, beginning with M13. From the look of the preview frame, it seemed to me 30-second subframes would get it, so I instructed Nebulosity to take 15 of ‘em with the Canon 60D. I hit the “go” button, and wandered off to see what my mates were up to. Since I’d told the camera to take internal dark frames (with an uncooled camera, it is good to take your darks immediately after the lights), completing the sequence would require 15-minutes rather than 7.5-minutes.
What was going on with The Bubbas? What was going on was M57. It looked so good in good buddy Ken's 10-inch Orion/Synta goto Dob—I thought I almost glimpsed the central star at high power—that I asked Taras if he'd send his 15-incher over that way.
At first, the elusive central star was no-joy, even at 450x, but, suddenly, as I stared, that pesky star winked in. I couldn’t hold it, but at powers from about 450x to 500x, it would make an occasional appearance. Averted imagination? For once, I don’t think so. Max and Taras also saw it. Which is damned good. While I’ve spotted it with my 12.5-inch a time or two, it is often invisible in a 25-inch. What helped? The clear skies were good, but I suspect the main things were that the Ring was close to zenith and that the steady seeing allowed the image to sit rock solid in the eyepiece. At 500x.
Just as I finished looking at M57, Nebulosity played the little fanfare that means, “Sequence is done, Boudreaux.” The last subframe on the screen looked good. The histogram indicated sufficient exposure. And it was easy to see the nearby small galaxy, NGC 6207, even in an unprocessed shot. So, I felt moved to go onto a new target, nearby M92.
M92’s fame, other than its status as a Messier, mostly has to do with it being Hercules’ “also ran” glob due to the nearness of stupendous M13. It was even smaller at 560mm than M13, but looked good nevertheless. I let M92 have 15-more frames at 30-seconds. I paid more attention to the subs as they came in this time, and noted the stars looked good and round and small in all of ‘em. Looked like we was on a roll, y’all.
After M92, I skedaddled over to M10, which was getting right low in the west. I probably should have done M12, too, but by the time I was done, 15-minutes later, it was maybe a little too close to the horizon murk to get started on.
With the whole of Sagittarius laid out before me, I had my choice of legendary nebulae and star clusters. I went for what is probably the best of the best, M8, the Lagoon Nebula. Not only did I need a picture of it for the Messier Album series, I wanted to see how the unmodified 60D would do with nebulae. A thirty-second preview showed substantial nebulosity and even some red color, so I thought we’d give it a go. 15 more 30-seconders.
Before I started the sequence, however, I removed the camera and SCA, screwed a mild light pollution filter onto the flattener, which is, hep-fully, threaded for 2-inch filters, and refocused. I’ve had good luck with my 1.25-inch Orion imaging filter, and I thought a mild Deep Sky-like filter would help with M8, which was a little low and almost into the horizon glow.
While I’ve had success with the Orion imaging filter, I didn’t go out and buy the 2-inch version. No sir buddy. Orion’s 2-inch SkyGlow imaging filter is 130 freaking smackers, and your stingy old Unk wasn’t ready to dish out that kind of moola for a relatively small amount of contrast improvement. I hunted around and found what I wanted at, of all places, Hayneedle.com.
They had a Zhumell (Chinese) 2-inch filter just like I was looking for for about 30 bucks. Guess what? Based on visual looks and the improvement in my images, its performance seems every bit as good as that of the 100 buck more expensive Orion. It’s ain’t fancy; the “Urban Sky Filter” filter don’t come with a data sheet outlining its bandpass. You get a nice looking 2-inch filter in a cardboard box labeled, yes, “filter,” a padded plastic case, and that is it. But it works, y’all. Hell of a buy in this old boy’s opinion.
How did the DSLR do with the Lagoon? My finished images show plenty of red nebulosity. Maybe tetch less than the astro-oriented 60Da, but despite what you might have been told, the difference is not like night and day. When it comes to nebulae, images from an unmodified Canon require slightly more care in processing to bring out the reds, but not much more, campers.
Like M8, M10, M92, and M13, the target that followed the Lagoon, M22, was another easy and spectacular one. But for its location, which is purty far south, which makes it a little less lustrous from mid Northern climes, this huge Sagittarius globular would walk all over M13. For me down here at 30 north, it is well on the way to doing just that. I could see from the subs that my images of M22 and its rich field would turn out right nice.
With the easy done and the night growing older, it was time to essay a couple of harduns. At the top of that list was NGC 6888, the Crescent Nebula in Cygnus, which can be a tough target (visually) for a 12-inch. I did a 30-second preview, and, at first, it looked like I hadn’t got nuttin’ honey. Peering more closely at the sub, however, showed the dim arc of nebulosity blown off by a misbehaving Wolf-Rayet star. While it was visible in a single 30-second shot, I thought I’d better kick the exposure up to 1-minute. Given the tracking I’d been having all night, looked like the VX would have no trouble delivering round stars with 1-minute unguided exposures.
And, indeed, it did not. The stars looked good in the subs, and the Crescent was “there” enough to make me believe it would look right nice after some processing. Which it did once I ran the final stacked image through Photoshop. I intend to go after it with Veronica again with longer guided shots in hopes of picking up more of the nebulosity between the horns of the Crescent, but I was pleased at my first crack at it with the Megrez.
|NGC 6888, the Crescent...|
When half an hour of exposures of the Crescent Nebula was finished, it was getting late and damp. Very damp. I had to dry the Megrez’s objective with Max’s dew zapper gun. While I had a 3-inch dew heater strip on the refractor, the 3-inch one was not large enough to go all the way around the scope’s over-sized tube, and the objective eventually gave way to the damp. Next time I’ll make better provisions.
Time for one last shot, I reckoned. I’d wanted to get a picture of Comet Jaques, but had heretofore been stymied by weather. While, given the way it looked in Taras’ Dob earlier in the evening, it was a mere shadow of its former self, it seemed worth a try with Veronica. In my finished images, it’s a little green fuzzball adjacent to a field star. If you hold your mouth just right, you can even see a small tail.
And that was that. Fun is fun, but done is done. With my small scope and relatively light load of support gear, I was packed up and ready to go in a surprisingly short time. By 12:30, Miss Van Pelt and me was rolling for the New Manse. Back there, it was a little cable TV (A Haunting) and a couple of Kolorado Kool-aids. What? No Yell? Nope. I was just too tuckered to enjoy the magic elixir.
Takeaways, muchachos? I was pleased with the evening’s images. They were decently exposed, easy enough to process, and showed mucho cool stuff. It’s remarkable how deep a silly little refractor will go. Maybe even more remarkable is how much easier it is to get pictures when your focal length is short and your mirror don’t have to move to focus. Once I was set up, I just started clicking off deep sky image after deep sky image like a crazed 1960s tourist. What’s next for Veronica? I’ve adapted a guide scope mount for her, and hope to try some longer exposures when I get good weather again. When that happens, be assured you-all will hear all about it.
Next Time: The IBM GEM...
Sunday, September 28, 2014
The Refractor Way: Part I
|A 4-inch achro just looks like a refractor...|
I see you out there, Joe and Jane Novice Amateur, looking all googly-eyed at advertisements for them pretty little refractors. You are not alone. More than a few veteran amateurs are not immune to the charms of 4-inch and smaller lens-type scopes. That’s not the question, muchachos. The question is, “What are they good for?” Are they worth the high prices (relatively speaking) commanded by color free apochromatic refractors or even the more modest sums achromatic refractors cost?
What’s the refractor story, anyhow? I ain’t gonna go through the whole nine yards concerning Hans Lippershey’s baby. I will just say the main threads of the refractor drama since telescope makers moved beyond the tiny lenses of Lippershey and Gallileo have concerned color and aperture.
The apertures of the early scopes didn't have to get much larger than an inch or two before astronomers began to be tormented by the color purple. What the hail am I talking about? As you prob’ly know, refractors use lenses rather than mirrors to gather light. The big lens collects light and refracts the rays, sending them to a focus point. An eyepiece, a magnifying glass, if you will, can be inserted just behind that focal point to enlarge the image for inspection by an observer. Sounds simple. Much simpler than, say, a Schmidt Cassegrain telescope. It is, but, alas, there is a catch.
As objective lenses became larger, astronomers noticed brighter objects—the Moon, planets, bright stars—were ringed with purple halos. This “false color” was bad enough to reduce contrast and sharpness. What was happening? Glass refracts different colors (wavelengths) of light by different amounts. The same principle that allowed Newton to see the rainbow of the spectrum with a prism was ruining astronomers’ views of the sky. All the colors of light were not being brought to focus at the same spot, resulting not just in color around objects, but, in the worst cases, a haze of purple that partially obscured objects.
The solution, at least a partial one, wasn't long in coming. Experimenters discovered long focal length lenses suffered less from this “chromatic aberration.” The longer the focal length of the simple single element objective lenses, the less obtrusive the color. Chromatic aberration was still there stealing sharpness, but it could be lived with.
|Public star party circa 1680...|
The result was the infamous “aerial telescope” of the 17th century. Refractors were made in insanely long focal lengths—as much as 125 feet for a 7-inch aperture scope. A seven inch had to be that long. The larger the aperture of the lens, the longer its focal length had to be to keep chromatic aberration bearable. Double the aperture of the lens, and you had to quadruple the focal length. This effectively made a 4 – 6-inch telescope a big gun.
Tubes in these absurd focal lengths were impractical given the materials of the day—it was impossible to keep flexure from rendering the scope useless. The Huygens brothers dispensed with tubes altogether, keeping eyepiece and objective aligned with a taut rope. What is amazing is that they and others made some landmark discoveries with these crazy telescopes.
There had to be another, better way and there was. John Hadley and, later, Sir William Herschel and others, inspired by Newton, made the reflecting telescope into a powerful instrument for astronomy in the 18th Century. Without an objective lens, there was no chromatic aberration, and mirrors were not limited in aperture by the “two times larger, four times longer” rule. Still, the refractor had its fans. It was a more robust instrument compared to the reflectors, which used polished metal mirrors that began to tarnish as soon as polishing was done. If only there were some magical way of getting rid of the dadgum color purple.
The fix for the refractor, or at least a more practical partial fix than 100 foot tubes, came in the mid 18th Century. A London barrister, Chester Moore Hall, discovered that a two-element refractor objective lens made with two dissimilar types of glass with different indexes of refraction reduced chromatic aberration tremendously. Hall tried to keep the secret of his "achromatic" refractors, but it soon got out.
While the achromat was a big improvement over the single element objective, it was not a complete cure. An achromat will show considerable color on bright objects at faster focal ratios, and, as with single element objectives, the larger the objective, the higher its focal ratio has to be to keep color down. A 6-inch achromat needs to be near f/20 to be (mostly) color free.
The achromats were a revelation and the savior of the refractor. Nevertheless, astronomers still wished for that elusive More Better Gooder. For most amateurs, that had to wait till 1977, when Japan’s Takahashi began selling the first widely available commercial apochromatic "color free" refractor. Tak led the way with telescopes that used fluorite lens elements, but they were soon joined in the apochromat business by today’s big names is refractors, including Astro-Physics and TeleVue.
|Could be the Moon, could be a custard pie...|
The principles of the “APO” refractor objective had been known since the late 19th century: lenses with more exotic glasses than crown and flint, sometimes including fluorite crystal elements, and objective configurations sometimes consisting of three or even more elements. What it took for the apochromatic refractor to become a practical reality was modern materials and fabrication techniques. And, most of all, an audience, serious amateur astronomers, who began to appear in numbers in the mid 20th Century—professionals had long since discarded the refractor.
The APO’s downsides? Cost and aperture. Perfection in the form of exotic and perfectly figured glass don’t come cheap. It is difficult for manufacturers, even given an unlimited supply of dineros, to find decent glass blanks of the special glasses good enough to make an APO lens. For the well-heeled amateur, a 7-inch APO is purty much the limit, and, in today’s terms, a 7-inch is a small scope. For the less affluent, like your old Unk and many of y’all, even smaller, 3 or 4-inches, is more like it.
Which brings us back ‘round to that sixty-four dollar question, “What can a 3 or 4-inch refractor do for you?” From a suburban backyard or from a semi-dark club site? Before I could refresh my memory as to the facts in that case, I had to locate the 80mm f/7 APO refractor that has lived with me and Miss Dorothy for many a year, but hasn't gotten much use lately. She's a beautiful little scope, a William Optics Megrez fluorite, but with the freaking Herschel Project going pedal-to-the-metal for several years, this little person, Veronica, had sat in her case for a weary old time.
Out to the shop went Unk to hunt up Miss Veronica; I remembered stowing her case out there during the move to the New Manse. There she was. Opening up the nice WO aluminum box revealed my little gal pal, who now has nearly a decade of miles on her. Her paintjob ain’t what it once was, and her poor dewshield ain’t exactly round anymore, the result of a fall to the floor of an observatory she took when she was new (don’t ask). Still, she looked good, with her pretty off-white tube, gold trim, retractable dewshield, and hefty Crayford rotatable focuser. All the parts and pieces was in the case, too, including the 2-inch WO extension tube necessary for almost anything to reach focus with her. Even the stalk for the red dot finder was in its accustomed place.
All I had to do to get Missy ready to go was gently clean her objective, which had a little gunk from who knows where on it, but which cleaned up nicely and soon looked pristine, and mount the finder, a selectable-reticle red dot job that I normally use with my Zhumell100mm Tachyon monster binoculars.
The mount? For the quick backyard run I contemplated, that would be my SkyWatcher AZ-4. I bought this alt-az mount (which you can still get in the U.S. of A. from Orion, if at a higher price than the SkyWatcher-badged version) for the C90, but it’s come in handy for everything from refractors to C8s to Unk’s homebrew f/6 6-inch Newt. There is a Vixen compatible dovetail screwed onto the scope’s “foot” that would allow me to mount Veronica on the VX GEM or the Atlas EQ-6, but I demurred. It would be a relatively hazy evening more than like, and I’d be a little tuckered from teaching my late afternoon astronomy lab, I figgered “AZ-4 on the deck” would be just about freaking perfect.
One good thing: here in the second week of September, darkness is now arriving at a more reasonable time, DST or no, with it dark enough to do some gazing by 8 p.m. When that hour arrived, I waltzed Veronica onto the deck, and went back inside to hunt up the eyepiece case and to give the scope a little while to adjust to the steamy outdoor temps. While a small refractor will normally present almost perfect images without acclimatization to outdoor temperature, it was so hot and muggy I didn’t dare remove the aperture cap for a while—the objective, coming from the air-conditioned house, would have fogged-up in a heartbeat.
Anyhoo, by the arrival of astronomical twilight just before 8:30, both scope and eyepieces had warmed up and plenty of stars had winked on. Yes, there were a few passing clouds early on, but a look north showed magnitude 4.3 Zeta Ursae Majoris was easy to see despite its relatively low altitude from out latitude. I know that ain’t exactly dark sky heaven, but it’s better than what I’ve had to deal with at home for the last quarter century and I know it’s better than what a lot of you put up with. On the other hand, the sky was certainly bright enough to provide a test of what a small lens-scope can do from a light-polluted backyard.
First stop was bright Arcturus, now getting low in the west. I wanted to check Veronica’s collimation on a bright star, given the abuse she’s taken over her life. Defocused the yellow star and, yep, alignment was still dead on. That is one of the beauties of refractors, y’all. You’ll often read a refractor will only need “infrequent” collimation. Actually, assuming your scope is of decent quality, it’s unlikely you will ever have to worry about collimation. Despite the only so-so seeing, I couldn’t resist giving Miss a quick star test, too. The patterns in and out of focus were, to my eyes, identical.
“What about color, Unk?” What color? I didn't even think about that. There was simply none. Not on Arcturus. Not on Vega. Zip. Zero. Zilch. It’s been so long since I’ve looked at the Moon with the scope that I can’t remember what Luna looks like with the Megrez, but I am guessing it is every bit as good as these bright stars color-purple-wise.
Now for rubber-meets-road time: “Can an 80mm refractor, no matter how good, satisfy in the backyard? On the deep sky?” Off to M13 we went. Given the wide field of the scope with my 100-degree 16mm Zhumell Happy Hand Grenade in the (Intes) 2-inch diagonal, about 3-degrees, finding M13 or anything else, even in relatively poor skies was trivial. There was Daddy-O Messier 13. Even at 34x, I had to admit he was looking dang good. Better than I remembered him being under similar circumstances in my 4.5-inch StarBlast Newtonian, and certainly better than he’d ever been in my good, old Short Tube 80 80mm f/5 (who now lives with Unk’s son, Chris). But I was not prepared for just how much better.
The view sure was nice in the 16mm 100-degree eyepiece. The globular looked surprisingly grainy, and the field stars was just so purty. So small. Yes, I know, stars just naturally look smaller in a small scope at relatively low power, but I ain’t gonna lie to you: stars are sharp and oh-so-pretty in a lens scope. Period. Anyhoo, in my quest for More Better Gooder, in went the 8mm Ethos.
DADGUM! (This is a family-friendly blog, y’all.) The silly little scope was actually resolving the Great Glob. No, it wasn’t a great big ball of stars, but it had gone from “grainy” in the 16mm to “real grainy” in the 8mm and, yes, as I stared I could see—with direct vision—cluster stars winking in and out. That, campers, is at least as good as what my 4.5-inch StarBlast can do from a dark site under better conditions and with higher magnification. The magic wasn’t just due to Veronica being a refractor, however; it had to do with her being a very good refractor. The Short Tube 80, much as I loved the little guy, couldn’t make M13, which is a fairly tight glob, look like anything more than a fuzzball from the darkest skies.
The results were similar for every DSO I pointed Veronica at. The Dumbbell Nebula, M27, showed form and substance. M92, Hercules' “other” glob, was small but grainy, almost wanting to resolve. M12, the loose globular over in Ophiuchus, didn’t just want to resolve; it broke into stars despite its low altitude. M57, the Ring Nebula, was obviously a ring. Under poor skies, M57’s donut hole is sometimes difficult or impossible to make out with a 4-inch reflector.
By 10 p.m., the bugs was biting, Unk was sweating, and clouds was moving it. One last look. How about Polaris? As most of y’all know, Polaris is double star. It's easy with a C8, but can be a challenge with a smaller scope. While Polaris' buddy is a sizable 19” from the primary, the differences in magnitudes—9 vice 2—can make it difficult to see. Veronica? She laughed, giving me a glimpse of the companion star just as clouds moved across the field.
And, with that, it was time to pull the Big Switch. Luckily, an 80mm APO on an alt-azimuth mount equates to “little switch.” In 5-minutes, I was back inside enjoying a cold one and watching a DVD of Star Trek the Animated Series. What was next? While I have a lovely little WO SD 66mm APO (or maybe “semi-apo,” whatever that means) refractor who performs admirably under dark skies, I believe she is just a bit on the wee side for a bright backyard. Up next would be a pair of scopes that have a little more aperture, 4-inches, if considerably less ritzy pedigrees.
With the my ST80, Woodstock, gone, there are “only” three achromats left in the stable, a modern Explore Scientific OTA, an f/6.5 AR102 Miss Dorothy won at last year’s Deep South Regional Star Gaze, an older Celestron (Synta) C102 f/10 4-incher given to me by my friend Pat, and an 80mm SkyWatcher f/11. I decided to leave the 80mm SkyWatcher out of the running for now, since I was purty sure she couldn't compete with the Megrez, and concentrate on the 4-inchers. The ES would get first crack at the New Manse’s backyard.
Unlike when you take your first glance at the Megrez, your initial impression of the AR 102 will likely not be “pretty,” but “odd,” or “gawky” or maybe, if you are being charitable, “different.” That’s not because of its beautiful gleaming white tube, but because of the peculiar dewshield—short and fat—the AR’s Chinese maker, JOC, bestows upon its refractors.
Look deeper, however, and I think you will agree this is an extremely nice scope. The focuser is a large and smooth Crayford (though not rotatable like that of the Megrez) and, like the APO, includes a slow motion/fine adjustment on one of its two large (metal) focus knobs. Put a 35mm Panoptic in the diagonal and point the tube at the zenith and there is no slipping whatsoever. The included tube rings are heavy and solid. Finder? One is in the box with the scope, a good 50mm. There’s also an outstanding 2-inch diagonal. Is the build quality of the scope as good as that of the Megrez? Of course not, but it’s surprisingly good anyway. How the hell Mr. Scott Roberts and company do this for 500 bucks, I do not know, but I hope they keep on doing it.
|She's kinda homely, but has a great personality...|
That’s not the true test of a scope, however; that’s images. I had no illusions that the optics of the AR could keep up with the Megrez's. The APO's fluorite objective alone is worth considerably more than the whole AR102. I did, however, remember the AR had done an outstanding job on the deep sky from the dark observing field of DSRSG last year. The question was how well it would do from a semi-punk backyard.
To find out, I removed Veronica from the AZ-4 and secured her in her case, replacing her with the AR102, who hasn't yet told me her name. While lighter than a C8, the AR102’s tube is somewhat longer, but is not a problem for the AZ-4. The telescope looked good on the SkyWatcher mount, I gotta say.
As night fell, it was apparent the AR102 wouldn't enjoy quite as good an evening as Miss Veronica had. It was clear, with the aforementioned Zeta UMi shining steadily. And if I held my mouth just right, I could even see the dimmest bowl star, magnitude 5.0 Eta, without much difficulty. However, there were bands of clouds passing through all night. I had to pick and choose my targets, and even the “clear” patches were not as clear as the sky had been on the previous evening. Be that as it fracking may, after five decades behind the eyepiece, I thought I could give the scope a thumbs up or down, clouds or no.
I’ll cut to the chase, y’all: the extra inch of aperture helped. If maybe not quite as much as I’d expected. That M13 was better in the ES was apparent as soon as astronomical twilight arrived. In a 7mm eyepiece (94x), it was everything it had been in the Megrez and a little more. It simply looked more like a ball of stars. I had little doubt that from a dark site, the Great Glob would have been looking awful good. At least as good as it is in my 5-inch MCT, Charity Hope Valentine. Part of the reason for that was that the 7mm eyepiece yielded slightly more magnification in the 4-inch than it had in the 80mm (80x), but that wasn’t the whole story. The extra inch of glass was picking up more photons and that made the star cluster better.
The results were the same with M92 and M12. They looked just a little better. M12 was slightly more resolved, and M92 actually showed some stars now and again. M15, while not at all resolved that I could see, was considerably superior to how it looks in the 4.5-inch StarBlast from better sites. Its halo was larger and the core was brighter than in my little green gremlin of a telescope.
|The vaunted Happy Hand Grenade...|
Maybe not too surprisingly, the 1-inch advantage was not as apparent on nebulae. Oh, M27 looked right nice, but better than it had in the Megrez? Not really. The same went for M57. I thought it might be a step up in the AR102, but it was not. The little smoke ring’s appearance was identical to what it had been in Veronica the night before.
The color? There was color, you betcha, but really only on Vega. At 41x, Alpha Lyrae was surrounded by a considerable (blue, not purple) halo. At 94x, the halo went from “there” to verging on the disturbing. While careful focus minimized it, this is a short focal length achromat, and you will not banish the color. You can mask it with a filter, but it will still be there reducing contrast. That said, none of the deep sky objects showed any color whatsoever. Neither did bright Arcturus. This would not be a scope for looking at the brightest stars, but I am unlikely to do that with it anyway. Caveat? It appears some people are more troubled by excess color than others.
How about the Moon and planets? The Moon wouldn’t be above the trees till late, and the planets, Mars and Saturn, were down behind the treetops to the southwest. I have never tried the AR on the Moon or the planets. My guesses would be: Venus purty much unbearable, Jupiter bearable and showing considerable detail, Mars OK, Saturn pretty, the Moon fine on the terminator with a loss of contrast on the disk. In other words, this scope would be alright for casual inspection of the planets, but not what you’d want if that is a regular pursuit. I will turn the AR to Luna, at least, one of these nights and report back.
One last impression: while the AR102 had a little more light gathering oomph, its images were never quite as nice as those of the Megrez. The stars weren't quite as sharp, and the contrast was not as high. There just wasn’t as much “pop” in the images. This was not quantifiable, but was my impression, nevertheless, and one that was constant throughout the evening with the AR.
Hokay, then, only one contenda remained, the old Synta-Celestron, the “C102.” There is no question it is a good-looking scope. No, the tube ain’t as long as that of a freaking Unitron, but it's long enough and hearkens back to that classic “long refractor” look. That’s enhanced by the nice faux brass paintjob Pat applied to gussy up a slightly worn OTA. The dewshield is a normal long and skinny one, and the Synta tube rings, while minimalist, work fine and look OK.
|Yeah, that's how a lens scope oughta look...|
The telescope’s focuser is a second-generation Synta rack and pinion. No, it is not nearly as smooth as the AR’s Crayford, but it works well and smoothly enough, and a rack and pinion has the advantage that it will not slip under most conditions. It is a 2-inch job, unlike those on some of the earlier Synta/Celestron 4s, and the pretty brass focus knobs Pat added complete the attractive picture. This sucka looks like a refractor.
The C102’s down-checks were few. The 30mm finder would have to go. Hell, I hadn’t much liked using the 50mm finder on the AR102 despite its bright images. This old boy prefers zero power finders. Luckily, I had a Synta red-dot sight that slid right into the mounting shoe on the scope. The original Synta dovetail was kinda pitiful, but it only took a couple of minutes to replace it with a nice ADM Vixen bracket that was sitting unused out in the Shop. The Celestron’s objective cell is not adjustable, but it’s unlikely you’ll ever need to adjust it, so that is a non-issue. Finally, the coatings on the objective aren't as good as those on the AR102, whose lens tends to disappear in room light.
Back in her box went the AR102 and onto the AZ-4 went the Celestron. The scope’s tube is, obviously, considerably longer than the AR’s and not much, if any, lighter. I wasn’t so much worried about weight as tube length, which is what really tends to cause trouble for a mount. I needn't have worried; the 4-inch f/10 was at least OK on the AZ-4. In fact, SkyWatcher used to sell the AZ-4 with a similar 4-inch refractor.
Yeah, I know us Baby Boomers still lust after the f/15 Unitron 4-inch Photo Equatorials of our youth, but dealing with the f/10 Celestron made me almost lose my desire for a true Long Tube. This was the only refractor I had to remove from the mount to get out the door easily. It was just too long and awkward otherwise.
It was also the only scope that impelled me to extend the AZ-4’s tripod legs to their maximum length. Even then, the tripod seemed too short. I can scarcely imagine what life would be like with an f/15. What’s the problem with pulling the legs all the way out? Any mount performs better with its legs at least partially collapsed, and that was sure true with my AZ-4 (which is, unfortunately, the model with extruded aluminum legs rather than tubular steel legs). The other two refractors were rock solid; the C102 was, yeah, shaky. Not fatally shaky, but shaky. 'Course, I was operating from the wooden deck; the scope would have been more stable on the ground.
Verdict under the stars? Celestron has been selling this scope in one form or another for over twenty years, is still selling it in slightly modified form, and it is easy to see why. The optics are amazingly good. Not that I thought so at first.
Arcturus was shining bravely in the gloaming, so we went that-a-way so I could get the red dot finder aligned. In focus, the star was showing much more chromatic aberration than the AR had. Not a tremendous amount, but a noticeable amount compared to the wide-field refractor, which had shown no appreciable color around the star. I was puzzled, natch, but, paying more attention, I saw how much Alpha Boötis was dancing around. I decided seeing and/or tube currents were the culprits and went inside to await darker and, I hoped, steadier skies.
At 8:30 p.m., astronomical twilight had arrived and another look at the star showed it to be free of that nasty colored halo and shining steadily rather than hopping around. Next up was a collimation check. Alignment was dead on. How about a little star test, then?
Amazingly, this old warhorse threw up an essentially perfect star test, with the in and out of focus diffraction patterns being identical far as my old peepers could tell. The results were on a par with those with the Megrez, and a hair better than the star test of the AR102, which, while quite OK, had shown just a hint of undercorrection. I hate to be the breaker of dreams, but the C102’s optics tested as good/better than those of any Unitron I’ve examined over the years.
There was one last bit of drama—or comedy, more like. I wanted to see what the C102 would do with Polaris’ companion. Turned to the North Star and saw nothing—nothing but the yellowish primary. That was all. Even with the 7mm it was just a single star. Huh! Then, staring up at the sky in puzzlement, I realized I not looking at Polaris, but at Kochab. Doh! When I had the real Polaris in the field, you coulda drove a truck between primary and secondary.
What I really was curious to know was whether would this telescope’s fine optics and 4-inches of aperture would put it in the lead over the other two refractors. There was little question M13 was a smidge better in the C102 than in the AR102 and the Megrez, but only a smidge. And I think that improvement was mostly because the Celestron delivered more magnification eyepiece for eyepiece, 143x in a 7mm vice the faster 4-incher’s 94x, for example. Anyhow, in the C102, M13 was one more click closer to being a ball of stars. Frankly, what really amazed me was that all three refractors made something of M13 from less than perfect skies. That’s something my comparably sized Newtonians—including my beloved long focal length Palomar Junior—simply cannot do.
The story was much the same on the other objects I looked at. M92, M57, M27 and the rest looked very good, but not appreciably better than in the AR102 or Megrez. Yes, there was some gain over the Megrez attributable to that extra inch of aperture, but it was not a slam-you-in-the-face kinda thing. As with the AR102, the stars looked good and tiny in the C102, but the images just didn’t have the somewhat ineffable breathtaking quality of those in the APO.
My conclusions regarding 80 – 102mm refractors are that they can and will do a good job for semi-casual backyard observing. They can indeed satisfy. How do you choose between a smaller (and much more expensive) APO and a larger achromat, though? That is simple. If you just want to look—at the deep sky—you won’t go wrong with an inexpensive achromat. If you want a more versatile scope that can do the Moon and planets and is useful for imaging (forget using an achromat for long exposure work unless you like huge purple halos and bloated stars) get an APO. The best APO you can afford. I’d rather have a real good 80mm than a so-so semi-apo-ED 100mm scope.
If you decide on an achromat, fine, I salute you. Don’t go hog-wild, though. A 6-inch achromat can be had for around 600 dollars these days, but don’t imagine it will give you a dose of More Better Gooder. The light gathering advantage of a 5 or 6-inch achromat is more than offset by the increase in color and resulting decrease in contrast (remember that dadgum “larger needs longer” rule).
My specific thoughts on the refractors I used over this series of nights are that all three amazed me with their capabilities. The true star was the little Megrez, though. Its images were just freaking terrific. While William Optics doesn't sell that particular model anymore, they have comparably good or maybe even better 80s for around 900 – 1000 dollars. Which, while it might sound high to the uninitiated, is a bargain once you start comparing prices for similar scopes from folks like Takahashi and TeleVue. The only surprise to Unk is that more observers don’t consider WO when buying refractors and eyepieces. Their products are still easily available in the states, including from one of Unk’s old favorite dealers, Anacortes Telescope and Wild Bird, and a newer outfit I like very much, Agena Astro Products.
What’s next for our three stars? You’ll hear more about Veronica, the Megrez, in Part II when we look at small-refractor imaging, one of the biggest reasons for getting an 80-100mm APO. The achros will get their place under the stars in the near future, too. The AR, will be going with us to DSRSG next month. The C102 (who just whispered to Unk that her name is “Amelia”) will take over from the ETX when Unk continues his Messier Album series. Charity did a good job on that, but Amelia is much closer to the spirit and goals of that project.
The C102 back inside as clouds rolled in—as they tend to do in mid evening in late summer down in the Swamp—Unk grabbed the Rebel Yell bottle and ruminated. I have never been a refractor guy, muchachos. In fact, I have often laughed about the obsession for small and exquisite lens scopes. Maybe in part because of my advancing years, however, I have to admit small is becoming more and more beautiful. Especially when coupled with “real good.” I will never abandon my love for CATs, but, yeah, in his golden years, Unk just might change horses—once in a while, anyhow.
Next Time: The Refractor Way Part II...