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 those pretty little refractors. You are not alone. More than a few veteran amateurs are not immune to the charms of 3 and 4-inch 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 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 point, resulting not just in color around objects, but, in the worst cases, a haze of purple that 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 reasonably priced 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 for many a year, but which 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 Lodge, 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 one of today's inexpensive medium-fast achromats. If you want a more versatile scope that can do the Moon and planets impressively well and is useful for imaging, however, you want an APO. Forget using an achromat for long exposure work unless you like purple halos and bloated stars. While you can get acceptable images with an achro, processing will be more involved and demanding.
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 necessarily give you a big dose of More Better Gooder. The light gathering advantage of a 5 or 6-inch achromat is at least somewhat offset by the increase in color and concomitant decrease in contrast.
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...
Sunday, September 21, 2014
My Favorite Star Parties: TSP 1999
For those of us who've been lucky enough to make the pilgrimage to Fort Davis, Texas and the Prude Ranch for the Texas Star Party, there is no question in our minds that it is indeed the mother of all star parties. That being the case, muchachos, I was gobsmacked to realize I’ve never said much about my first and maybe best visit to that legendary gathering of amateur astronomers.
Actually, TSP 1999 was technically not my first year at the Texas Star Party; that came in 1997. But ‘97 didn’t really count. It wasn’t held at the Prude Ranch, you see, but at Leakey, Texas in the Hill Country to the accompaniment of mucho humidity and clouds, and one extremely violent thunderstorm. I had a good time, nevertheless, but I was still determined to do the real TSP “someday.”
That day did not come in 1998, but it did arrive the following year when Miss Dorothy and I found our work schedules at the height of our careers would actually allow us to not only take a week off, but to take a week off at the same time. In May. The month of TSP 1999, which would be held from Sunday, May 9 to Sunday, May 16.
That’s been, strange as it is for me to realize, all of 15 years ago now, but I still remember how pleased I was Miss Dorothy was positively enthusiastic about doing the TSP and making it our big summer vacation, especially given the bloodcurdling tales I’d told about 1997. Yeah, I was on quite a high—till I learned all the rooms on the ranch were gone.
Today, I’d have thought long and hard about making the trip without having lodging on the Prude (dude) Ranch. A decade and a half ago, though, I was a little younger and a lot braver. Hell, I’d survived Leakey, Texas in a pup tent. Prude Ranch should be duck soup compared to that, especially with a better tent. Miss Dorothy was not overly enthusiastic about a week sleeping under canvas, however, so we reserved her a room at a nearby motel, the Fort Davis Motor Inn. She could stay on the field when she wanted to, and be comfortable in the motel when she didn’t. I’d also had some semi-assurances from the TSP staff that a room would “probably” become available for us in a day or three.
The only remaining question in Unk’s mind? How the hail would we get everything in the Toyota Camry? “Everything” to include, in addition to Unk’s 12-inch Dobsonian telescope, all the clothes and camping gear we’d need for a week way out west. Somehow, and I don’t know how, I crammed it all into our Japanese sedan and even managed to leave room for me and Miss D. I reckon the only thing that made that possible was the fact that my friend Pat and I had converted the 12-inch, a Meade StarFinder, “Old Betsy,” to a truss-style configuration the previous year.
Anyhoo, early on Saturday morning the 8th of May we pointed the car west on I-10 and began our journey. We’d decided not to push hard on day one, with our goal being merely to reach Houston, where we’d spend the night with Dorothy’s brother, Ed, and his wife Bobbie. It was fun seeing Ed and Bobbie, and it was nice to take a break after what is probably the worst part of the trip west, the drive across the Gulf Coast and into Texas. Not only is that stretch boring, in 1999 the roads were in terrible shape with construction slowdowns everywhere—we were routed off the Interstate at least once and for quite a few miles in the area of Lafayette, Louisiana. Still, stopping at Houston was a bad idea.
We paid for our break the next day—in spades. It is a long, punishing drive from Houston to Fort Davis, which is about as far west as you can go without running out of Texas. Over 11 hours. While we got an early start, 5:30 in the a.m., that wasn’t early enough.
What is west Texas like? It comes on you slowly. After the Texas coast comes San Antonio and the Hill Country, which is really more like Houston (or Possum Swamp) than it is different. After San Antone is in the rearview mirror, however, I-10 turns north as it meanders west and you eventually realize you haven’t seen a tree in a while. Humid east and coastal Tejas is replaced by the more arid landscape of Texas’ fertile ranch land. A few hours farther west, and the landscape morphs again, becoming near-desert. Finally, the horizon begins to bloom with hills way different from the gopher mounds of the Hill Country, hills that soon grow into (small) mountains.
It took freaking forever, y’all, but eventually we were just about at the fabled Prude Ranch. We stopped for gas one last time at a station that would have been right at home in a 1950s science fiction movie. One with a giant bug/spider/lizard crawling in off a spooky desert to menace the townsfolk as tumbleweeds blow in an eerie wind.
|The Upper Field...|
Shortly after that stop, we left I-10 for good and before too much longer were rolling onto the ranch, which, late on Sunday—it was getting on toward 5 p.m.—was a bustle of activity. There were amateurs everywhere, setting up scopes, erecting tents, and just getting ready in general for a night that would obviously be a spectacular one. There wasn’t a cloud in the late-afternoon sky, which had that purplish tint that spells “great observing.”
That was the good; there was also the semi-bad. After we checked in at the main ranch building, which includes not only the registration desk, but also the dining hall and the large auditorium where TSP talks and other star party events are held, we headed for what I’d been told was the place to set up, the Upper Field. Alas, it was packed to the dadgum gills. Not surprising when you consider that the attendance figure for 1999 topped out at around 800 deep sky crazy astronomers. We orbited the field several times, but there just wasn’t a single square foot of space on which to set up even a modest sized Dobbie.
Luckily, the Upper Field was only one of two main fields in use. We settled for the less desirable Lower Field. What else could we do? Actually, the Lower Field was fine. It was pretty dusty, but so was the Upper Field that year; the Ranch hadn’t received appreciable rain since the previous November. Yes, there was a line of hills to the east that throttled back the horizon, but there really ain’t no bad sightlines on Prude Ranch. One thing was actually superior on the Lower field: there was a stand of several trees on its western side and we found space for our little tent under one of ‘em. I was hoping that would do at least a little to keep the tent cool in heat I feared would verge on the brutal.
With the day rapidly wearing away, D. and I didn’t waste time getting the scope and other gear set up, which was amazingly simple in those innocent pre-computer/goto days. Plunk down rocker box, insert mirror box, bolt truss tubes and upper cage to mirror box and I was done. Other gear? That consisted of my observing (card) table, the eyepiece box, a notebook containing my observing list, and a copy of the vaunted Herald - Bobroff Astro-Atlas.
|Miss D. hanging out in our little home...|
The tent could have been a problem, I reckon, but it wasn’t. Despite my loathing for tent camping these days, I did a considerable amount of it in my youth and was an experienced tent-pitcher. I’d also had the good sense to set up our new Coleman in the backyard as a test before we left home. The dome tent was easy to get together, but it sure looked smaller than it had in the backyard. Unfortunately, I hadn’t learned my lesson from TSP 1997: never buy a tent you can’t stand up in. When it’s time to change clothes, you will hate it. Anyhow, with the tent up, we inflated the air mattresses and declared ourselves done.
Since Dorothy planned to stay onsite the first night, we didn’t have to visit the motel; all we had to do was wait for darkness. Which takes a long and weary old time in the spring at Fort Davis. You are far west in the Central time zone, and it’s not dark enough to do much of anything before nearly 10 p.m. Luckily, it was suppertime, and our first meal in the Ranch House’s picturesque dining hall filled the empty hours.
I’m sure you’ve heard tales about the quality (or lack of it) of Prude food. I am here to call B.S on that—leastways concerning the years I’ve attended. The meals, served cafeteria style, featured large portions, the entrees were varied, and there were always fresh vegetables—and even a salad bar. Most attendees were content to eat on site, and I know Dorothy and I never got around to trying any of the restaurants in Fort Davis. No need to.
Supper wasn’t just about food, it was about becoming reacquainted with fellow amateurs we hadn’t seen or heard from in many a Moon. Internet astronomy was burgeoning in 1999, but it still wasn’t the big deal it is today. Even in the late 90s, the main way you kept in touch with your amateur buddies was still by attending club meetings and going to star parties.
Supper done, we strolled the Ranch in the gloaming. It was obvious everybody was in a good mood and having a good time. A sign on the windshield of a car parked next to ours read, “For I am gone to Texas to confer, converse, and otherwise hob-nob with my brother wizards,” and that was purty much how we all felt on the cusp of an outstanding night of astronomy.
|Land of the BigDobs...|
What else did we find out during our stroll? Prude Ranch was a lot like what I imagined an old fashioned dude ranch from the 1930s - 1950s would be: rustic, but not too rustic, clean, and staffed by friendly folks. That was the good. The bad was that because of the lack of rain the dust was incredible. There was no stopping it from getting into your eyes and hair and clothes—and telescope.
The Prude dust is not like what you might imagine, either; it is nothing like sand. It is very fine, talcum fine. I used to joke that what it was was fine dust mixed with the manure of countless generations of horses and spiced with plutonium dust blowing in from the National Test Side in Nevada to the west. The bottom line was that you just had to live with it. A water truck went around every afternoon wetting the ranch roads to try to keep dust raised by vehicles down, but that was a futile effort in a land so parched.
After what seemed like an eternity of waiting, a Texas spring night arrived. Out at Prude, that means it is considerably darker than what you are used to. There was no appreciable light dome from Fort Davis that I could see, and the legendarily draconian Texas Star Party light rules (a Coke machine on the far south end of the ranch had its plug pulled so its rather dim red illumination couldn’t disturb us) meant walking around the Ranch, even with a (suitably dim) red light, was challenging. I didn’t do too much wandering the first night, however. After spending a few minutes just staring open-mouthed at the stellar multitudes, I got Old Betsy rocking.
I’d planned to take it relatively easy the first night, doing bright Messiers and other showpiece objects and turning in when I got tired(er). It had been one hell of a long day—to the tune of eleven freaking hours on the road. I figgered I’d be lucky to make it till midnight.
Oh, how glorious those Ms were. The bright galaxies M101, M51, M81, M82, and M83 looked as much like their photographs as they likely ever will in Old Betsy. And they were all so danged easy to find. I didn’t even remove the lens cap from my 50mm finder. With so many “guide” stars visible, it was trivially easy to find anything with just a Telrad (this was long before Betsy got her digital setting circles, of course).
|Old Betsy and Unk's LX-1...|
My telescope was performing amazingly well, with the most distant reaches of the Great Out There opening before me. An hour or two passed, and I discovered that not only was I not ready for bed, I wasn’t as tired as I had been when I began the run. In fact, I was ready for challenges. I’d had my fill of the bright and easy and grabbed the notebook of charts I’d printed out with my favorite computer program in them days, Megastar.
I began chasing the hard and the weird. Stuff like the Twin (Double) Quasar in Ursa Major and Copeland’s freaking Septet in Leo. I wasn’t sure how many of these out-on-the-edge type objects I’d find, but I was ready to try for them. Amazingly, the most difficult objects on my list kept falling prey to my “little” 12-inch. One of my epiphanies on this trip was that under the right skies a medium sized scope can be an incredibly powerful performer.
Almost before I knew it, it was after pea-picking 3 a.m., then or now Unk’s usual limit. Actually, it’s rare that I go that long when standing at a scope observing visually. It’s different at TSP, however. For one thing, you have plenty of moral support. The folks around you, and there are plenty of them, have driven as far or farther than you have, and nobody wants to waste a minute of the amazing skies. It’s a matter of honor to keep on keeping on as long as your pals.
Another help was The Voice of the Texas Star Party, K211BI, the TSP’s very own FM radio station. An eclectic mix of music—Beethoven followed by the Grateful Dead followed by big band music—was broadcast all night long (together with star party news and announcements) and kept me alert when conversation with my neighbors, like a new buddy who was set up next to me, airline pilot and amateur astronomer extraordinaire, Tom Wideman, lagged.
Finally, a big plus was the late-late night concession stand in the area of the Ranch House, adjacent to Prude’s indoor swimming pool. They were selling not just hot coffee, but everything from burritos to ice cream. I blundered around the Ranch by red flashlight and got lost a time or two on my way to the food, but the grub was well worth it.
After I finished my burrito, I decided to do a little walk-about of the fields to relax. By this time of the night/morning, most folks were, like me, finished with their observing programs, and I was able to cadge some looks through the Upper Field’s monster scopes. This was the first time I’d observed with a 36-inch scope other than a slow focal ratio professional instrument, and I was floored by what a really big Dob will do for the most nondescript NGC galaxies.
I finished my night with a tour of the summer Milky Way with my old Simmons 10x50 binoculars, which, like Betsy, seemed to have increased their aperture at least twofold. As the hills to the east began to become visible in the rosy light of coming dawn, Dorothy, who’d turned in earlier, arose to see the stars turn out their lamps, a very old horned Moon rise over the mountain, and hear the horses begin to snuffle as they awoke.
|Sun setting. the bathhouse is in the background center...|
Not everything was poetic that morning, however. I’d forgotten how uncomfortable a sleeping bag on an air mattress is. Not that that made much difference. I was only able to sleep a few hours anyway. By nine, the interior of the tent was like an oven. I never felt hot outside on the hottest days thanks to the low humidity, but inside an enclosed space like a tent, it was a mucho different matter, campers.
Monday morning, fairly early Monday morning, we were up thanks to the high temps in our poor little tent. First order of bidness was my morning ablutions in the bathhouse on the north end of the field. How was it? Oh-so-much better than the Black Hole of Calcutta in ‘97 at Leakey. The only problem was that the dust around the bathhouse was so deep that you were dirty again before you made it back to your tent. It was bearable, in other words, but I sure hoped we’d get that sorta-promised Room on the Ranch ASAP.
Next up was getting Miss Dorothy settled at the Fort Davis Motor Inn. The name made the place sound a little more substantial than it turned out to be. It was your average small independently owned motel. Not much different from what you used to see all over the country until the end of the 1970s. It was clean enough, and it was air conditioned, and there was no doubt Miss D. would be way more comfortable sleeping in her room than I would be in that Coleman tent.
Monday proceeded at a decent enough pace. There were meals in the Ranch House and plenty of friends old and new to hang with, and, maybe most of all, cool astro-stuff to drool over in the spacious vendor’s hall.
Well, “spacious” is maybe not quite the word. There was sufficient room in the little structure just off the Upper Field, but it was nothing like the huge building at Leakey in 1997. Nevertheless, the 1999 vendor lineup was impressive, and included TeleVue, Lumicon, Pocono Mountain Optics, Eagle Optics, Telescope Warehouse, Astronomy to Go, and AstroSystems among others. I was thrilled to meet the legendary (and friendly) Al Nagler for the first time.
I had also been hoping to meet the author of SkyMap, Chris Mariott. If there was a program that was neck and neck with Megastar in the hearts of us deep sky fanatics in them days, it was Chris’ SkyMap Pro (which is still going strong). Unfortunately, while there was a Skymap table, the person manning it informed me Chris wasn’t there. Apparently, he was not a fan of air travel and demurred when it came to flying in all the way from the UK.
|Behind the Vendor Hall...|
“Hell, we know you, Unk. What did you buy, huh, what did you buy?” I was going through a planetary observing phase at the time, and was awful tempted to grab a handful of the new TeleVue Radian eyepieces, especially after receiving a personal demo of them in a TV refractor by Uncle Al himself, but given the expense of the trip out west, I held my buying in check. I’d been needing a 2-inch Barlow, and satisfied my gear lust with TV’s Big Barlow (purchased from the much-loved and long gone TV dealer Pocono Mountain Optics), which I still have and use to this very day.
The rest of Monday? Following supper, we had plenty of time to get Miss D, who was in the mood to do some resting after our crazy Sunday, to her motel before sundown. Out on the lower field when darkness came, it was much the same as the previous night: nothing but clear skies and amazing views. It was a very late night for Unk. I didn’t stay awake just to continue hitting the harduns, either. The real treat came in the wee hours with an incredible naked eye view of the summer Milky Way when it crept over the mountains. It didn’t look like the Milky Way I was used to. What it looked like was exactly what it was: an enormous spiral galaxy viewed edge-on and sporting a mind-blowingly detailed equatorial dust lane.
I didn't just look at the Milky Way, I imaged it in my simple fashion of those days. I mounted my old Ricoh 35mm SLR or a home-made "barn-door" tracking platform (which my fellow star partiers dubbed "Rod's LX-1") and fired away with that beloved emulsion, Fuji Super G800. Today, I'm surprised I got anything with such cheap, simple gear, but my pictures actually ain't bad at all.
One other thing I did before throwing the Big Switch Monday night/Tuesday morning was something I hadn’t done in a long time. Using a printout from Megastar, I tracked down Pluto’s rich field, drew it, and came back to it a couple of nights later to see that the speck I’d identified as our favorite dwarf planet had moved. I’d seen Pluto a time or two in the past, but he was way easier to spot with a 12-inch from Texas skies than he had been with a C8 under the more humid Arkansas heavens.
Tuesday, Miss Dorothy declared she Had Had Enough of the motel, and camped out in the Ranch office, resolving to stay there till we were given that vaunted Room on the Ranch. Guess what? It worked. By late afternoon, we’d checked Dorothy out of the motel and were moving into one of the “Family Cabins,” actually one of several motel-like rooms adjacent to the Lower Field. It wasn’t like staying at the Hilton, or even the Chiefland Days Inn, but it was large, air conditioned, and had a real bathroom with a shower. It was freaking luxurious after my little tent on that dusty field.
|Zombie Unk at mid-week...|
Wednesday was notable for bringing the start of the daytime presentations, including the Planetary Panel, which consisted of my late friend Jeff Medkeff, S&T’s Gary Seronik, another late friend, David Healy, and myself. Yeah, it seemed a little strange to be discussing the planets at a star party devoted to deep sky voyaging, but our presentation was well received. One dude did come up to me shortly after we left the stage to apologetically say, “Hey, man, real sorry I missed y’all’s talk on planetary nebulae.”
This was an excellent year for daytime talks at the TSP, with some standouts being “Observing the Bear at the TSP” from powerhouse deep sky observer Larry Mitchell, and “Planetary Nebulae Beyond the NGC: The Good, the Bad and the Ugly” given by Houston amateur Jay McNeil.
Wednesday night found your poor old Uncle on the horns of a cotton-picking dilemma. I’d finished my long, long observing list. I’d been all the way through that thick notebook of Megastar charts. What do do? Only one thing: get started on the TSP’s official 1999 observing project, “A Planetary Party.” This was a list of 49 planetary nebulae put together by the Houston’s John Wagoner. Challenging? I’ll say. Many were tiny, requiring “blinking” with an OIII filter for identification, and many were in unfamiliar constellations like Lupus or tucked away in dusty, out of the way corners of more familiar star pictures.
By Thursday, Mr. Wagoner was sporting a t-shirt that read “TSP: Twenty-five Stinking Planetaries.” Our goal was to observe at least 25 of the 49, a number I achieved on Friday night. It was a long journey, and one that couldn’t begin in earnest until early morning when the Milky Way was above the mountains to the east. Nevertheless, Unk and a record number of observers persevered, earning the coveted Planetary Pin.
The star party’s evening speakers, which the TSP has long been noted for, were outstanding. On Wednesday night, Steve O’Meara gave a presentation I particularly enjoyed, “Oh Night Divine: A Tribute to Walter Scott Houston.” O’Meara’s tribute to the dean of deep sky observers left us well and truly pumped for a night of deep space exploration.
|I still wear my pin with pride today...|
Thursday evening (the talks always wrapped up before the coming of astronomical twilight) was the U.S Naval Observatory’s Brent Archinal with “Like Gold and Silver in Sands in Some Ravine: Star Clusters.” Brent’s program on the neglected open clusters of the NGC was very well done.
Finally, on Friday night came the keynote by David Levy. On this last night of TSP 1999, he brought us “More Things in Heaven and Earth: Finding Passion in Nature.” David’s presentation touched on many things, but what was mostly on display was the passion for the night sky for which he is famous.
‘Course there was the earthly as well as the sublime. One evening just at sundown, a herd of deer came charging onto the Lower Field at full gallop. I thought for sure the result would be wrecked telescopes and injured deer aplenty, but their leader, a big buck, saw that those crazy humans were on the field with their crazy stuff, and turned his herd around at the very last moment.
Our luck with the sky continued through the week. On Thursday night, we did leave the meeting hall to find the sky covered in clouds, and some of us even pretended to be disappointed (in truth, more than a few observers would have welcomed a break after four long, uninterrupted nights). The weather reports we were getting suggested the sky might clear at full dark, however, and that was just what happened. As twilight ended, the masses of clouds scuttled off, leaving in their wake one of the best nights of the whole star party.
Friday? More of the same. Incredibly dark and clear skies all night long. One thing I should mention for the uninitiated: the truly dark, clear skies of the southwest don’t look that dark. The sky background actually looks dark gray rather than inky black. You’ve obtained full dark adaptation and are registering every single photon, photons from things like airglow, zodiacal light, and far distant earthly sources.
As the end of the week came, Dorothy and I had settled into the TSP routine and were thoroughly enjoying Ranch life. In addition to observing and visiting with our fellow astronomers, we found time to do a little sightseeing. We toured the nearby Davis Mountains State Park, which offered some incredible vistas. The drive through the park wound to the top of a small peak, and standing there looking out at the valley below, the view was strange and almost alien. I wouldn’t have been surprised to witness a saucer landing—or an atomic bomb blowing its top in a landscape that looked a lot like Jornada del Muerto Valley.We also made it to “downtown” Fort Davis, for ice cream at the famous Fort Davis Drug Store, which has an old-timey lunch counter cum soda fountain right out of Dobie Gillis. There were a couple of nice restaurants in town, too, including one at the historic Limpia Hotel. I never did get by for their legendary “chicken fried chicken,” unfortunately. The evening we planned to do that turned out to be Mexican Food Night on the Ranch and no way we were gonna miss that.
Only one thing remained on our agenda: a tour of nearby McDonald Observatory. Not only was visiting both the modern telescopes—like the gargantuan Hobby - Ebberly—and the historic instruments fun, the drive up the mountain was exciting, to put it mildly. An old-fashioned cowboy right out of Zane Grey “helped” by his dog drove us up in the most cantankerous jalopy of an old bus I’d ever been on. Naturally, we paid a visit to the Observatory gift shop for goodies before bracing ourselves for the trip back down to the Ranch.
And, suddenly, the end was nearing, dangit. Saturday evening brought the huge TSP raffle, the Great Texas Giveaway. There were tons of prizes from Nagler eyepieces to a portable observatory tent. Even Unk, who never wins anything, came away with a Milky Way print by David Lee. Then it was time for one last journey to the stars.
Like everybody else, I was exhausted from nearly a week of hitting it hard every single night, but on I pushed, nevertheless. By midnight, however, I knew Big Switch Time was approaching. There was the beginning of that fearsome drive home to face on the morrow. The great goddess Urania seemed to agree, as clouds moved in at 1 a.m. “That’s enough sky for this year, Unk. I’ve given you all I have to give. Now, go to bed and leave me alone for a while.” And so I did.
Passing under the “Vaya Con Dios” sign as we quitted the ranch Sunday morning, Dorothy and I promised ourselves we’d make it back to the TSP as soon as we could, which turned out to be in 2001, another spectacular year. Which was to be our last TSP for a while—we've actually never made it back—but not our last forever, I hope. I intend to do the big star party at least one more time before I am too decrepit to face traveling across the Lone Star State with a ton of astro gear. Maybe not next year, but the year after for sure. I have to, you see, because in 1999 I learned that the stars at night really are big and bright deep in the heart of Texas.
Nota Bene: You can see more pictures from TSP 1999 on Unk's Facebook page...
Next Time: The Refractor Way Part I
Sunday, September 14, 2014
Destination Moon Night 7: Obscured by Clouds
No, you can't always get what you want
No, you can't always get what you want
No, you can't always get what you want
But if you try sometime, you just might find
You get what you need…
—Jagger - Richards
One thing I swore when Miss Dorothy and I moved out of glorious old Chaos Manor South, the original Chaos Manor South, the Old Manse, was that I would make up for all those long years where my observing had been limited due to work and the skies and trees of downtown Possum Swamp. I won't say I’ve been out with a telescope every cotton-picking clear night since we relocated to Hickory Ridge, but near about (not that there've been that many of them since spring). I’ve even done some fairly ambitious work from my backyard here at the New Manse.
That includes some things I hadn’t done from home in twenty years. Like prime focus deep sky imaging. Yeah, I did a fair amount of lunar and planetary photography from the Garden District till the trees finally hid the sky in the late 90s, but deep sky? No way. I wouldn’t have dreamed of trying. Out here in the suburbs, it’s an entirely different kettle of fish, y'all.
I found out soon after we moved in that I could do plenty of video work. The bright objects were no problemo, as my Mallincam Xtreme /AstroLive snap of M57 shows. On those so far rare occasions when I get a cloud and haze free evening, I can go considerably deeper. Yes, I have to use a filter, the Orion Imaging filter, a mild light pollution filter like Lumicon’s old Deep Sky filter, to tone down the bright background a hair, but I expect the Mallincam may surprise from the backyard with the clearer (maybe) skies of fall and winter.
|Ring with Xtreme...|
Assured that I could see something with the video camera, I began to wonder about prime focus DSLR imaging. A Sky & Telescope assignment impelled me to stop wondering and see what I could get with my Canon from home. Verdict? Not too shabby. I probably should have imaged at an ISO a stop faster than I did, but my results were surprisingly good given the presence not just of haze, but a near full Moon.
Let me also say rat-cheer that the new PHD Guiding, PHD Guiding 2, shore didn’t hurt none. If you don’t have a copy of the latest edition of amateur astronomy’s best-loved autoguiding program, get it right now. It’s still free, y’all. Impossible as it may be to believe, PHD 2 is even better than the original; it just LOCKS ON to that consarned guide star.
Assignment done, I lollygagged through quite a few evenings—most of them cloudy and none of them good enough for pitcher taking—till one night when I began to think about my good, old Atlas mount. Last time I’d used my much-loved heavyweight GEM at the Possum Swamp Astronomical Society dark site, the previous winter, I’d had problems.
On that night, I’d gotten inconsistent results while using the EQMOD program to control the mount. The goto alignment would work OK, but shortly thereafter, the mount would get confused, pointing every which-a-way. Which was disturbing, since I had never had a minute’s problem with EQMOD.
What’s that, Skeezix? You don’t know what an “EQMOD” is? Have a look at this old blog entry from Unk’s vault of moldy oldies, but, in short, it’s like NexRemote. It is a program (technically an ASCOM driver) that takes the place of the hand control and adds many new features to the Atlas EQ-6 (it will also work with the Sirius HEQ-5, the AZ-EQ-6/Atlas Pro, and Synta’s new EQ-8 and the Orion version of that big mount). It even lets you use a wireless gamepad as your “HC,” just like NR.
I have almost always used EQMOD for imaging with the Atlas. It works well and I'd never had to give it a second thought till that last time out. I believed the troubles I had at the dark site had nothing to do with EQMOD, however. I was convinced a loose power cable connection was the culprit and took pains to add some strain relief to the power cord at the mount.
Shortly after I finished the S&T assignment, I decided I’d try some prime focus imaging with the Atlas and my old C8, Celeste. I hadn’t turned the mount on since we’d moved in, and I wanted to assure myself the power cable fix had done the trick. I set up C8, Atlas, and computer, but wimped out on EQMOD. The sky looked iffy, and I figgered it would be easier to just use the SynScan HC. It worked perfectly—I had no trouble getting 10-minute guided subs of good, ol’ M13.
Still, I thought it would be a Good Thing to make sure EQMOD was again firing on all cylinders. The next semi-clear night that came, I hit the backyard with the Atlas and C8 once more. Since I just wanted to try EQMOD, I left the Canon in the gadget bag and hung my Mallincam Xtreme on the scope’s rear cell. At first ever’thing was ducky. M13 was in the center of the video screen right where he belonged. But, as before, things suddenly went south, with the Atlas not being able to find its rear end with a flashlight.
It was pretty clear now that there was something wacky with EQMOD, and I was purty sure that something was either the EQDIR module (which converts serial data from the computer to levels the mount likes) or the serial cable. Since the EQDIR and cable are both going on seven years old, I don’t have too much heartburn about replacing either one or both of them if further troubleshooting dictates I do so. Stay tuned.
At the end of them there alarums and excursions, I was tired, sweaty (it’s still in the mid 80s at night down here), and put out. I sure didn’t feel like disassembling scope and mount, and just covered Celeste and Atlas with the Desert Storm cover and retired inside to watch the Braves lose another one to the freaking Dodgers.
Late the next afternoon, I decided, given the clouds that had hung around all day, I might as well tear down the Atlas, and proceeded into the backyard. What should I perceive in the gloaming, though? That the sky was trying to clear. It was at least giving birth to some substantial sucker holes. I further noted that there was a right purty little half Moon in the sky. Hmm…hadn’t done any imaging for Destination Moon, my crusade to image 300 lunar features, in a while…hmm…
Well, why not? Why shouldn’t I continue my tour of Hecate? Several reasons. I was being eaten alive by the skeeters despite having lit a citronella candle (I hate burning up those rather expensive Thermacell pads and butane cartridges for an informal backyard run) and doused myself with Deep Woods Off. It was also hot, with my iPhone girlfriend, Siri, asserting that the temperature an hour after sundown was 85 and that it “felt like” 90. Most seriously, the sky was crazy-hazy. Nevertheless, on Unk pushed. I already had the scope set up so it was the matter of a few minutes to get the Toshiba laptop plunked down on the table on the deck and hooked up.
Well, hooked up to the ZWO camera anyway. I removed the Mallincam and f/3.3 reducer from Celeste’s rear end (sorry, dearie) and replaced them with my old Meade flip mirror, the 1.25-inch Meade 12mm reticle eyepiece, the ZWO ASI120MC camera, and my time-honored Orion Shorty Barlow.
Where I screwed up was I forgot to hook the serial cable to the SynScan HC so I could send the scope on lunar gotos with Virtual Moon Atlas like I did last time. Just as I was preparing to fire up the cam, I realized I’d forgot all about VMA. Instead of correcting my error, however, I decided to do things the old-fashioned way. Which was a mistake.
With VMA, I don’t waste time imaging features I already have in the can but have forgotten about—I have notes in the program appended to every feature that’s completed. I can also use the built in ASCOM “hand control” for precise object centering. Oh, well, didn’t look like it would matter much, anyhow…another batch of clouds was suddenly obscuring Diana’s shining visage.
The clouds came, but they also went. Sort of, anyway. It was never really clear, and the seeing was never very good at all, even in the more or less cloud free intervals, but conditions were at least a little better than they had been on Night 6, and the pictures were OK, if not close to what the li’l ZWO can do on those rare good nights.
Werner and Aliacensis
Werner and Aliacensis are two nice, reasonably fresh-looking craters lying just 145km from a large and detailed crater, Walther, which, unfortunately, is not on my 300 list. Werner is a round, 70km, deep formation with steep, terraced walls and a mostly flat floor littered with scattered debris and lacking a real central peak. This young-looking crater dates from the Eratosthenian Period (3.2 – 1.1 billion years ago).
The adjacent crater Aliacensis is a little larger than Werner at 80km in diameter. It is also not quite as deep nor is it as perfectly round. It is older than Werner, having been formed during the Nectarian Epoch (3.92 – 3.85 billion years ago), and looks it, having a distinctly eroded appearance. I picked up a few craterlets scattered across Aliacensis’ floor, as well as the small off-center mountain that serves as the crater’s central peak. What or who is an “Aliacensis”? I didn’t know either. Mssrs. Chevalley and Legrand say, “[He was a] 14th century French Geographer and theologian born in France.”
Faraday, Stofler, Fernelius, Licetus
The next group was just to the south down the terminator, and was quite a spectacle even given the conditions, since going south meant I was approaching the Moon’s feature-rich southern highlands. As I likely don’t have to tell you, craters are everywhere there and figuring out which is which can be quite the challenge. I finally identified my quarry with the aid of VMA, but I sure wished I’d hooked up that dadgum serial cable.
Faraday is a battered 70km diameter crater that just missed being eradicated by two impacts that broke its walls, Faraday A on its northeast rim, and Faraday C on the south. The main crater has a messy looking floor and no true central peak. Several craterlets are visible. The walls of Faraday are steep and fresh appearing in my picture despite the crater dating from the Pre Nectarian, 4.55 to 3.92 billion years ago.
If Faraday A and C almost wiped out Faraday, Farday’s impactor dang near took out the larger adjacent crater, 126km Stofler. Like Faraday, Stofler also comes from the Pre Nectarian time, and also sports well-defined walls that, unlike Farday’s, appear terraced. Away from the damaged area caused by Faraday, the main features of Stofler’s floor are the many craterlets and Stofler F, a sharp and round crater that has done a number of Stofler’s southwest wall.
On the north slope of Stofler is Fernelius. Due to the low Sun angle in my photos, Fernelius looks fresh and sharp. With a higher Sun, however, it is old and eroded. Coming from the Lower Imbrian time (3.85 – 3.75 billion years), it is a little younger than the previous two craters, but doesn’t look it. Its main features are a mostly flat lava-covered floor and a small crater, Fernelius B, that has broken the northern rim.
Licetus, another Pre Nectarian crater, is a 75km diameter formation 184km south of Stofler’s center. It’s a nice looking crater, and would appear almost perfectly formed save for two small craters on its southern walls that have caused considerable damage there. In addition to a group of central hills, the floor possesses a small crater, Licetus C, near the steep western wall.
Aristillus, Autolycus, and Cassini
I jogged back north and took a dip in magnificent Mare Imbrium to capture these three remarkable craters, of which Cassini is perhaps the most remarkable looking. In fact, there’s not a more identifiable crater on the Moon. This 58km formation isn’t the largest or the deepest or the youngest crater on the near side (it dates from Lower Imbrian days), but you can’t miss it sitting off the shores of Mare Imbrium not far from the great crater Archimedes.
What makes Cassini so readily identifiable is not its round steep slopes, but its floor. The flat lava-covered floor has one large crater, Cassini A that has a pair of rilles extending from it, and one smaller, but still impressive crater, Cassini B. That description doesn’t sound unusual, but as you can see in my sunrise picture of Cassini, it is just weird looking.
Off to the north, some 211km from the center of Cassini, is a crater I referred to as “Copernicus Junior” when I was a youngun and just beginning my exploration of the Moon. While not nearly as magnificent as the near side’s numero uno crater, Aristillus is still impressive and shares some things in common with its larger cousin, the fractured looking landscape around it, steep terraced walls, and a complex central peak (which you can’t see in my pic; the crater was still filled with night when I snapped it). This 58km diameter crater, like Cassini, comes to us from Lower Imbrian times.
Aristillus’ neighbor, Autolycus, is another goodie, if not as pretty as Aristillus. This nearly round 40km diameter feature is much younger than the other craters we’ve toured tonight, having been formed in Copernican times (1.1 billion years ago – present day). Anyhoo, it features steep semi-terraced walls, and a flat floor with a central mountain (invisible when I shot it).
With clouds building again, back north I went to the “waters” of Sinus Medii, the small sea near the “center” of the Moon, for a look at Triesnecker. While Triesnecker is a good-looking deep crater, you don’t hear it talked about much. The main draw in this area is the Rilles crisscrossing the Mare, including the awesome Rima Hygenus and a network of smaller rilles, Rimae Triesnecker. The crater itself is admittedly fairly pedestrian. It features steep terraced walls, and, when you can see it, a flat floor with a central peak. Being from the Copernican Epoch, it looks fresh and new.
Triesnecker’s image safely resident on my hard drive, the weather gods said, “Fun is fun, but done is done.” Haze and passing clouds morphed into thick, dark suckas, and Diana’s silv’ry lamp flickered and went out. Which was pretty much OK with Unk. I was damp with sweat and had been bitten by who knew how many skeeters (they love me…when we are at the dark site, my mates say Unk is the next best thing to a bug zapper light). How sweet it was to just cover the scope with a desert storm cover, and carry the laptop into the blessedly cool den where much cable TV and Yell awaited.
The next day I did my usual thing: stacked the frames from the ZWO with Regsitax, sharpened ‘em up with the program’s famous Wavelet filters, and did some minor tweaking with Lightroom and/or Photoshop. I knew there was only so much I could expect given the conditions, but I was reasonably pleased with the results anyhow.
I may make one minor change to my processing procedure, however, muchachos. A lot of lunar and planetary workers, including Unk’s talented compadre Robert Reeves (who has an excellent article on lunar imaging in the current issue of Astronomy), are no longer using Registax for stacking. Instead, they are using a program called Autostakkert, which, they say is better. They still use Registax’s Wavelet filters, but they stack with AutoStakkert first. My preliminary tests have convinced me that AutoStakkert does indeed do a better job and that the resulting images are just better. There's a gibbous moon hanging in the sky now, and if I can get up the gumption to brave the skeeters on another muggy night, I may try to obtain more data for AutoStakkert to chew on. I will let y'all know how it goes.
Total: 74 Down, 226 to Go.
Next Time: My Favorite Star Parties: TSP '99...