Thursday, January 22, 2015

 

Pretty Little Patriot Redux


Yeah, muchachos, I know. Uncle Rod and Miss Dorothy were supposed to have been off on another Chiefland Astronomy Village deep sky tear this week with the new CGEM and the C11, Big Bertha. The weatherman had other ideas. The closer we got to our Thursday morning departure, the worse the forecasts became. If there is a dog’s chance in hell of getting anything, I am not reluctant to make the six hour drive down, but when it's clear all we’ll see is the inside of  the Chiefland, Florida Quality Inn? That is another matter.

Sunday, weather forecasts for the CAV were looking poor. Not dire, but the handwriting on the wall began to be visible. On Wednesday morning, the outlook had not gotten better; if anything it was worse. Reluctantly, we cancelled out motel reservations. I was sorry to do that, but the bitter memory of our most misbegotten CAV trip ever in January of 2014 lingers in Unk’s mind. Well, if I couldn’t observe at the Chiefland Astronomy Village, maybe I could play with one of my refractors in the cotton-picking backyard.

It’s been quite a while since I reported on my 66mm William Optics Patriot SD refractor. Six freaking years as a matter of fact, and even then the little thing didn't have a starring role, being overshadowed by my paean to my good, old C8, Celeste. I did praise the Patriot for her wide-field views of the Herschel 400's larger open clusters under the dark skies of CAV, but after that trip I put her back in her case and left her there. For a long, long time.

The Patriot had done well on the star clusters of the Herschel 400, but as I finished up the rest of the list, began the Herschel II, and then the Herschel Project, my quest to view/image all 2500 aitches, there wasn’t much left for a little telescope to do.

There’s a limit to what you can do with a 66mm refractor, after all; even in the grab and go role it is nudged out by my 80mm lens-scope, which can show more and isn't much harder to, well, grab and go with. But, nevertheless, the 66 is a cool looking little thing, and she takes good pictures.

Really, the only sad thing about this 66mm refractor is that she is a dodo. Sort of. She ain’t clumsy, but she is extinct. She and her 66mm sisters were the rage for several years as the upscale heir to the Synta 80mm f/5 achromats, but then the big Chinese factories turned their efforts to bigger ED and APO refractors. The 66mm SD gave way to a 72mm, and even those scopes are no longer as widely available as they used to be.

What were these little refractors like? No matter who put their brand name on ‘em or what color their tubes were painted, they were nearly identical under the hood. Much more solidly built that your Synta 80, that’s for dadgum sure. Integral, sliding dew-caps, upscale rotatable Crayford focusers, fully baffled tubes (the Patriot has 10 baffles), reasonably fast focal ratios of f/5.9. That’s not the most import part of the story of these telescopes, though; that’s what’s up front, the SD objective.

What the hail is “SD”? It stands for “special (low) dispersion glass.” Really, it is the same as ED, “extra (low) dispersion” glass. The two-element objectives of the little scopes include one element of special glass (FPL 51, usually) that reduces chromatic aberration. With the modest apertures of the 66mm scopes and at their reasonable f/6 focal ratios, color is not a problem and is only noticeable (and is just noticeable) on the brightest objects. Before the 66es disappeared, William Optics was also selling versions with 3-element objectives, and even a Petzval set up, but the two-element model was always the most popular.

While a number of outfits slapped their name tags on these nice little scopes, the big players were William Optics (then with a U.S. branch) and Astro-Tech (the house brand of astro-dealer Astronomics of Norman, Oklahoma). Both companies sold the scopes in a variety of color schemes; you could get blue ones, white ones, black ones, and gold ones. But there was only one Patriot.

You have to be of a special mindset to appreciate some telescopes, and especially the Patriot. Not only is Unk basically a patriotic sort, and a vet, he admires scope paintjobs some might call tacky, like my ETX125, Charity Hope Valentine, whose tube is emblazoned with a silkscreened image (in color, yet) of the North America Nebula. The Patriot kicks things up several notches from there, y’all. She is all decked out in red, white, and blue. Stars and stripes, that is. Not enough? There’s a full-color American eagle on the tube near the focuser.

When William Optics offered to let me swap out my dour, blue-tubed 66 on a Patriot back in 2007, they sent me a brochure with full color pictures of what would become the most famous—or maybe infamous—66mm ED refractor of all time, so I thought I was prepared. When she arrived, however, I quickly decided the pictures had not quite done the scope justice. The little thing was a fraking Technicolor explosion. But, as I said in a long ago post, “Gaudy? I think she’s beautiful!” And I still did eight years hence, even if I wasn’t using the Patriot anymore.

What got my li’l 66 out of mothballs? Mainly my desire to image M31, the Andromeda Nebula (“Galaxy” for you younguns). That huge island universe is too large to fit in the field of even my 80mm f/7 refractor. During the long ago CAV run recounted at the link up top, I’d taken some well-framed shots of the object with the Patriot and my old Meade DSI, so I figgered the little scope would be perfect for Andromeda-imaging with a Canon DSLR.

One thing I knew for sure; the Patriot was capable of taking good pictures. When I was first learning CCDing, I got a couple of nice shots of the notoriously dim Rosette Nebula with the Patriot. “Dim” was no problem for the Patriot, of course. As you-all probably know, an f/6 66mm scope is just as capable of imaging a dim (extended) object as an f/6 200mm aperture scope. All that differs is the image scale; bigger for the bigger telescope. While I liked my shot of the Rosette’s donut, it had one failing, bloated stars, and thereby hangs a tale.

I was using an SBIG ST2000 CCD camera for the Rosette imaging run, a camera designed for astronomical use. Unlike DSLRs, it, naturally, lacks an IR filter to attenuate the red/infrared wavelengths. That is good in that it makes red nebulosity POP. It’s bad in that stars bloat badly when you use the camera with a refractor. The cure is to place a 1.25-inch IR block filter on the camera’s nose-piece. The trouble was that I’d left that consarned 1.25-inch nose-piece at home. I’d have to attach the camera directly to the scope with a prime focus adapter. The problem there was that there is no way to thread a filter onto my SCT prime focus adapter.

“Well, Unk, why in the name of everything that is holy would you want to use an SCT adapter with a refractor?” Because I had to, Skeezix. Aside from her paintjob, the most unusual thing about the Patriot (and her sisters) was the presence of an SCT style rear port on the Crayford focuser. It is threaded for standard SCT accessories, and that’s mostly what you have to use. Wanna 2-inch diagonal for your little guy? You have to use an SCT style diagonal.

There was good and bad inherent in that arrangement. The good was that the threaded tailpiece allows very secure attachment of cameras. The bad is that not all SCT accessories work. You have to have one with a threaded ring. A threaded tube, a 2-inch SCT visual back, will not, for example, work. It threads on and keeps threading till it runs out of threads and is never secure. That means no non-SCT 2-inch accessories can be used in the scope.

The above is not a problem for visual use, and it was not a problem when shooting pictures with the Meade DSI and my ST2000. I couldn’t figure out how to use a field flattener or a reducer, but the field was purty wide without a reducer, and the chips of those two cameras were too small to be affected by edge of field problems. In these latter days, however, I’d be imaging with the Canon DSLRs and their far larger chips. I’d just have to see how bad the field curvature was and try to rig up some kind of solution if it was not acceptable.

The de-mothballing of the Patriot took place months ago, friends, and I still have not taken a shot of M31 with it. The reason? Clouds punctuated by Moonlight. I’ve still got time to get an M31 shot this year, but not much time unless we get a spate of good weather. Thus far, the conditions have not encouraged me to haul a scope and mount out anywhere other than to the backyard. Not even to the Possum Swamp Astronomical Society Dark Site. I’ve done considerable imaging from the backyard, but the sky’s too bright to make it easy to get a worthwhile picture of Andromeda.

When the Moon finally got out of the way in late January, a visitor beckoned, Comet Lovejoy, C/2014 Q2. The comet was no Hale-Bopp or Hyakutake. It broke magnitude 4, but just barely, topping out at 3.8. That meant it was too dim to catch the attention of Joe and Jane Sixpack (or be easily visible with the naked eye from the suburbs). Nevertheless, it was "spectacular" as us amateurs reckon such things.  I found it just barely short of exciting in my Burgess 15x70 binoculars, even with the presence of the nearby gibbous Moon just before the comet’s peak.

Naturally, every amateur astronomer with a camera began to post comet pictures on the fraking Facebook. Lovejoy was a very photogenic stoplight green with a long, thin, narrow, spiky tail. Naturally Unk wanted to get in on the fun, but there came more clouds. Then rain. Lots of it. Eventually, there was a bit of improvement, but it wasn’t enough to impel me to pack up and head to the PSAS site. If I got the comet, it would be from the backyard of the New Chaos Manor South.

While the weather forecast for Friday the 16th was not overly encouraging, it was good enough to impel me to set the VX mount up in the backyard and round up the Patriot. I actually didn't have much rounding up to do, since I’d checked the scope out at the same time I’d put the Megrez 2 back into service, and knew exactly where she was. What I did have to do was bolt a Vixen compatible dovetail onto her foot. Like many William Optics refractors, the Patriot has a bolted-on mounting “foot” in lieu of rings and a dovetail. You can mount the scope in a Vixen saddle via this foot, but it isn’t very secure. It was no trouble, however, to attach a hefty WO Vixen plate onto this foot with a ¼-20 bolt.

Before I could image Lovejoy I would, of course, need to know where the dadgum thing was. My fave planetarium program, Starry Night Pro Plus 6.0 got me the coordinates in quick order. Purty much any planetarium or planner program would have done the same, but few make getting comet positions as easy as SNPP. It automatically downloads updated orbital elements for comets and asteroids at startup, so all I had to do was search on and find Lovejoy. A right click and the selection of “Generate Ephemerides” from a menu, and I had a list of the object’s right ascensions and declinations for the evening.

With darkness arriving, it was time to do the VX’s goto and polar alignments. I was not planning on guiding—didn’t figger I’d need to at  less than 400mm of focal length—so I wanted to be careful with polar alignment. I did all 4 calibration stars in hopes of getting as close to the pole as possible during the All Star Polar Alignment procedure (which depends on the quality of your goto alignment), slewed to Diphda, ran the polar alignment routine on that star, redid the 2+4 alignment just be on the safe side goto-wise, and declared myself ready to go.

Well, I’d be ready once the Canon 60D was on the scope. Taking care of that was simple: screwed an EOS T-ring onto a standard SCT camera adapter, attached that to the Canon in lieu of a lens, and screwed the whole shebang onto the Patriot’s SCT rear port via the prime focus adapter’s threaded ring. Different for a refractor, but the SCT adapter does provide a very secure mounting for a camera.

Next was focusing. I like to do rough focus on a bright star, so I slewed the scope over to Aldebaran, which was not too far from the comet on this night. I hooked the Canon to the Toshiba laptop using the nice, long tether cable Miss Dorothy got me for Christmas, and ran Nebulosity 3. When Neb was going, I turned on the 60D, selected the camera in the program’s menu, and dialed in an exposure of .5 second. I then mashed “frame and focus,” and tweaked focus until the orange star was as small as I could get it. When it was, dimmer field stars began to pop out, and I continued adjusting the Patriot’s Crayford till they were as small as possible.

That is still not good enough. When I was done with rough focusing, I pushed the “Fine Focus” button. Neb then instructs you to click on a (non-saturated) field star. When you do so, the zoomed-in star is placed in a small window and you are presented with two sets of numbers, “Max,” and “HFR,” (half-flux radius). I mainly just watch HFR, and focus till it is as small as it gets (Max will then be as large as it will get). That’s all it takes. I never use a Bahtinov mask and don’t pine for an autofocus system.

Rubber meets road time. I navigated the dadgum NexStar Plus’ menus till I got to “Goto R.A. Dec,” and entered the first coordinate pair on the list I’d printed from Starry Night. The motors hummed and stopped, I upped the exposure to 1-second, hit frame and focus again to make the cam take multiple exposures, and saw…nuttin’ honey.

Which was surprising. One thing you can say about the VX is that her gotos are always dead-on after a decent alignment. All over the sky. Still, the comet was in a spot that’s difficult for most goto systems, approaching zenith. I had another suspicion as to what the problem was, howsomeever. A look at my list of R.A.s and decs showed the values I’d used were for an hour from now. Was the comet moving fast enough that it would be in a significantly different position in an hour? Mebbe so.

I ran back inside to my office, generated a fresh ephemeris for the current time, scrawled the figures on a scrap of paper, scurried back outside, and punched them into the HC. Ahhh! There he was, almost dead center in the frame. Bright little feller. And not really so little, either. In a half second exposure the head/coma was surprisingly large. Time to get the picnic underway.

What I most like about Nebulosity is that once I get it running I don’t have to worry about it. It is very reliable and has never messed up an imaging sequence or crashed. I told it to give me 30 exposures with a duration of 30-seconds each. I intended to start with short ones in case the comet was moving real fast, and up them to a minute or two minutes in the next series. I wandered back inside to the den for a little TV and let Neb do its thing.

Unk ain’t no dummy. Not a complete one, anyhow. Even given the reliability of Nebulosity and the VX mount, I was wary. Every astrophotographer has a couple of friends, Mr. Murphy and Mr. Finagle. If something bad can happen, you can darned well bet it will. So, after about 10-minutes I stepped out onto the deck during a commercial break in—what else?—Finding Bigfoot to see what was up.

At first it ‘peared all was well. Another frame clicked off just as I approached the Satellite laptop. But what the hail was with the background? It was a nasty-looking reddish-brown. “Hmmm…that usually means…GULLDERNIT!” Yep, a look up showed the formerly clear, if hazy, sky being rapidly covered in clouds. I’d got only nine thirty second exposures, not nearly enough to show the tail well, I feared. So, you can bet I was amazed and happy the next morning to see I actually did capture the tail, if barely. Standing there looking up at the clouds that night, however, Unk was right put out. Nuthin’ for it but to pull the accursed Big Switch and go in search of the Rebel Yell bottle.

There was something different when it came to pulling that switch on this evening. Looking at the ten-day weather forecast on TWC, it appeared we might get a string of maybe four-five nights of acceptable, if not great, conditions. That being the case, I chose to cover the scope with my Desert Storm cover instead of tearing the rig down, and I chose to hibernate the scope rather than just turn her off.

The NexStar HCs, both the Plus and the older models have a hibernate feature that allows you to shut down the scope and preserve its alignment. The current alignment values are stored in non-volatile memory, and as long as you don't physically move the mount, no alignment is required when you wake it up the next evening. I followed the instructions, placing the scope in my desired position (I moved her with the HC until she was on the R.A. and dec marks), hit Enter, and turned off the power when the hand control told me to. I’d never used this feature with the VX before and was interested to see how well it would work.

It worked very well, even if that was about the only thing that did Saturday evening. When darkness fell, I went out and turned the mount on. The HC displayed the time from the mount’s Real Time Clock and enquired as to whether that was OK. Little fast, but close enough for government work, so I hit enter. The HC then responded with “VX Ready.” We’d see about that-there. I decided a focus check was in order and issued a goto command for Aldebaran. When the VX stopped, the star was dang near dead-center on Nebulosity’s display.

Otherwise? Well, the night wasn’t bad; it just wasn’t good. Tracking in two-minute subs was fine.  The computer and Nebulosity behaved well. But the sky was just not there. There were no clouds, just real, real poor transparency. I could tell by the look of the raw frames onscreen that is wasn’t going to be much of a night. Nevertheless, Unk forged on. It was marginally clear, and who knew when that would happen again? When I had had enough frustration I hibernated the VX again.

Almost unbelievably, campers, the sky held on for yet another night. In fact, Sunday was noticeably better than Saturday as far as transparency. However, I suspected that the comet, which was really taking a powder now, might be a little dimmer on this evening. Hokay. What say we speed things up with a focal ratio even faster than f/6? How to do that? Well, the Patriot had an SCT back; what if I screwed a standard SCT focal reducer onto it? That would get me really fast optics and might the corrector aspect of the reducer/corrector flatten the refractor’s field? I decided to find out.

When Sol was out of the way, I screwed the reducer/corrector onto my pretty little Patriot, attached the Canon and prime focus adapter to that, and woke up the mount. As before, goto was perfect following hibernation. When the motors stopped, a big blob I knew was Alpha Tauri was once again close to the center of the screen. I started rough focusing, and began moving the scope’s drawtube in. I knew it would be a close thing, and had removed the prime focus adapter’s extension tube. Close, but no cigar, y’all. I needed at least an inch more in-travel.

Oh, well, good idea even if it didn’t work, I reckoned. I continued with the fleeing Lovejoy anyhow, doing 2-minute subs all evening. When the fuzzball crossed the Meridian, I began to keep a close watch on the camera’s position with regard to the tripod’s legs. When it got a mite close to one, I stopped the exposure sequence, and issued a new goto command with the current R.A. and declination values of the comet. When I did that, mount did what us GEM lovers call a “meridian flip;” it moved to position the scope on the east side of the mount to track the comet as it descended into the west.

The photos I got on this night were my best I’d, but it was still disappointing that I couldn’t quite make the tail pop out like folks shooting from darker locations could. Well, what if I tried a dadgum light pollution filter? I’m not big on filters for astrophotography, since they change color balance and dim the images. Still, a mild filter like the 30 buck Zhumell imaging filter I’d picked up last fall might help a little. It had undeniably improved my shots of nebulae from the PSAS dark site.

The problem was how to attach the dadgum thing to the camera. As above, the SCT prime focus adapter makes no provision for filter use. There was no place to screw one on.  Well, dern. Howsomeever, I also had a 1.25-inch filter, a similarly mild one from Orion, I’ve owned for a couple of years and used with my Mallincams occasionally. What if I attached that to the nose-piece of an inch-and-a-quarter non-SCT prime focus adapter and inserted that into a 2-inch/1.25-inch adapter in the Patriot’s rear port? I rounded up my Orion prime focus adapter. Its 1.25-inch nosepiece would accommodate a filter, but its body was clearly too long to allow me to reach focus. Dangit.

Hmmm… Digging deep, way down deep, into the old Junque Box, I fished out a Meade prime focus adapter I’d had since the 1980s. It has a 1.25-inch filter-threaded nosepiece and a body at least an inch shorter than the Orion’s. Comparing the SCT adapter and the Meade side by side, it looked like the Meade might be just short enough to work.

Monday was MLK Day, so I didn’t have to teach my classes at the University and was able to hit the backyard for, amazingly, a fourth straight night of astrophotography. Following another successful awakening of the mount (I am loving that hibernation feature, if’n you can’t tell), I started focusing. Moved the focuser in an inch. Aldebaran was still a blob, but a smaller blob. Still plenty of in-travel. ‘Nother half inch. Smaller still, but still way out. I was beginnin’ to sweat now, with about half an inch of travel remaining. Little bit more and, bingo. With about ¼-inch left, we were close to focus, and I was able to tweak it in with Fine Focus. In the end, I had about 1/8-inch to spare.

How’d the filter do? It improved Lovejoy’s tail a little. Given that the comet was now slightly dimmer than it had been when I began the run on Friday, I believe it helped significantly. When I’d fired off the last shot of Lovejoy I wasn’t quite ready to hunt up the whiskey, however. M42 was above the trees in the darkest part of the sky, and I couldn’t resist shooting old faithful.

I knew the results wouldn’t be great. You don’t get “great” with a sky as bright as mine, but what came from my messing around with Photoshop and Lightroom was good enough to please old Unk, as you can see here.  The “messing around” consisted of significant processing to get rid of (most of) the nasty light-pollution gradients and some artifacts caused by the filter (I think).

So that was the end for the comet, more or less. I did get out with my C102 and do a little visual looking (finally) as the evil gray and white fluffy things rolled back in Tuesday and that was purty much the denouement. That was hardly the end for the Patriot, however. It will be my scope of choice for wide-field vistas from this time forward, I think. The little thing is just so EASY, muchachos. Easy to set up, easy to use. She’s solidly built and light, and even if I didn’t like her fancy raiment, I’d like that, muchachos.

Next Time: More My Favorite Fuzzies…

Sunday, January 18, 2015

 

A CGEM Comes to Chaos Manor South


I didn’t want that much, muchachos. Just a mount that would handle my Celestron C11 OTA for visual work, video imaging, and Moon pictures. It couldn’t be too expensive and it couldn’t be too heavy. And it had to have spot-on goto. I didn’t want to have to futz around with exacting polar alignment to get that, either. I wanted to be able to point the dadgum thing vaguely north and have whatever I requested be in the field for visual work.

Deciding which mount would fill that bill was, as I told y’all last time, tough. Till I had a gull-derned epiphany. What I really wanted was just a bigger Celestron CG5 or VX. Not too scaled up in weight and price, though. Only one mount fit that description and that was the standard Celestron CGEM.

As you also heard last time, I soon got a CGEM on the way from Bob Black at Skies Unlimited and busied myself getting the NexStar GPS C11's, Big Bertha’s, OTA off her fork, not a completely trivial operation, but one that only consumed a single morning.

When I was a sprout I thought Christmas took forever to arrive, but that was nothing compared to waiting for a big new piece of astro-stuff. Luckily, there were no winter storms and we were past the holiday rush, so the tracking on the UPS site showed the mount and a dovetail for the OTA, which I’d ordered from B&H, were proceeding normally and on schedule for delivery Monday, less than a week after I’d ordered ‘em.

With Bertha squared away and sitting on the table in the sunroom, there wasn’t much else to do. Oh, there was one thing. I moved the Atlas tripod, which features a TPI spreader system, into the sunroom from the garage. If the Atlas and CGEM tripods were identical, I planned to use the Atlas’ tripod for the CGEM. If not, I’d move the spreader to the new CGEM tripod. The Atlas is only used with a C8, so it really doesn't need the TPI spreader to strengthen its tripod.

Pore old Unk fidgeted all through a long weekend, taking occasional looks at the UPS website. Still said “Monday,” but would Monday ever come? I also kept an eye on the dadgum Weather Channel. The prognosis seemed to be that I might get some time under the stars Monday. Not much, and there would be clouds, but maybe a little.

Monday a.m., I busied myself working on my latest Sky & Telescope assignment to try to make the day go quicker. I expected the UPS truck wouldn’t roll through Hickory Ridge till around 4. You never know, though, and anything that went by on Pine Needle Drive that sounded anything like a brown truck brought Unk to a window at a run. Mid afternoon actually went quicker than I though it would. Miss Dorothy arrived home with a nearly flat tire, and by the time I’d got her beloved Xbox (Scion XB) up to the Trax Tires over by the University and got the little thing a new shoe, two o’clock had come and gone.

When I got home, Miss D. reported that nary a brown truck had she seen. Back to Microsoft Word went Unk. Not for long. The sound of another truck caused me to look out, and what should I see but a UPS vee-hickle in the driveway. I headed for the front room (“Music Room”) post haste. Surprisingly, and a little disturbingly, by the time I got the front door open, the UPS dude has already deposited three boxes on the porch and was on the way back to his truck. No doorbell. No request for signatures. Whatever. IT WAS HERE.

“It” being not only the mount’s two boxes, but the single box containing the Celestron D-type dovetail.  I’d had a premonition that only two boxes would appear, that the Dovetail I needed to get the scope on the mount would be MIA. I’d armed myself with printouts from the UPS website in case I needed to make the UPS dude to check his truck one more time, but all three were, yep, there on the front porch.

I wrestled ‘em into the Music Room as a first move. Well, “carried” the box from B&H; it was light enough. The other two were handfuls. The long box that, I presumed, contained the tripod was heavier by far than it should have been, so I suspected it also held the 17-pound CGEM counterweight. The other box? I had to set that down in the den once on my way to the sunroom, my chosen assembly area.

For the next hour or so, Miss Dorothy wisely kept herself out of the sunroom. It was inhabited by a wild man, and packing debris was flying everywhere to the accompaniment of sounds that no little resembled the legendary rebel yell. I took things slowly and carefully, but after owning a CG5, a VX, and an Atlas, I was on a pretty well-trodden path. Figgered I’d start with the tripod box.

Part of that (double-boxed) box was indeed taken up with the hefty CGEM counterweight. While heavier than the VX’s weight, it was in the same modern style. The mount comes with only a single 17-pound counterweight, and I didn’t expect that to be enough. I was hoping the addition of the 12-pound VX weight would be enough, howsomeever. If not, there was no lack of old (compatible) 11-pound Synta pancake weights ‘round here.

Declination counterweight put aside, I lifted the tripod out of the box. It was in perfect condition, and at first glance didn’t look any different from the Atlas’ tripod setup nearby. It turned out there was one minor difference:  the peg the azimuth adjusters push against was, as I’d heard, a little taller than the one on the Atlas. I could have exchanged pegs between the two, but I gotta admit, campers, the new tripod was so pretty I decided to use it instead. I’d transfer the TPI spreader bars to the new tripod once assembly was done. I snapped the hand controller holder, the last thing in the box, to a tripod leg and pressed on.

One thing I did to the new tripod immediately was wipe down the threads of the center bolt and apply a thin coating of bicycle chain grease. The last Celestron mount I bought was fatally flawed in that area. After I screwed the VX tripod center bolt into the mount head for the first time, it seized up, and I had to destroy the bolt and the hole it threaded into to remove the tripod so I could ship the whole works back to Celestron. Hoped that wouldn’t be a problem this time.

Now came the pay off, the big Bubba of a mount itself. The heaviest box contained the CGEM head, the counterweight shaft and lock nut, the hand controller, cables, two azimuth adjustment bolts, the manual, and—something of a surprise—a copy of the NexRemote CD. Seeing as how my VX came with a TheSkyX disk, I’d assumed NR was a thing of the distant past. There was also a manual that was no better nor any worse than any other Celestron manual. “Adequate” in other words. I browsed through the thing to make sure there were no gotchas regarding the CGEM, and got back to work.

First out of the box was the hand control, which was a standard model, not the new Plus version. That, I thought, was a Good Thing. Oh, I’ve gotten used to the VX’s Plus HC, but I will never like it as much as the old one with its M and NGC shortcut keys. Anyhow, I set the HC aside along with the declination counterweight shaft and nut and a bag containing two cables, a too long 12vdc cord and a too short serial cable. I screwed my courage to the sticking place and lifted the big GEM head out of the box.

First impression? If the CGEM is any lighter than the Atlas EQ6, it ain’t by much. Second? After the tripod’s central bolt threaded smoothly into the mount, and the mount was secure on the tripod, I inspected my new GEM. I was impressed by how much Celestron prettied up the EQ6. You can still see its Atlas heritage, but just barely. Everything is more attractive and modern looking. The mount ain’t gaudy, however. You’ll see some with orange declination and R.A. lock levers and orange-headed altitude and azimuth adjustment bolt heads. Those are aftermarket accessories. Stock, it’s fairly subdued. There’s orange trim around the end of the RA housing and around the altitude pivot, but that is it.

How about improvements? The heads of the azimuth and, particularly, altitude bolts are much larger and easier to turn than those of the Atlas. The altitude scale has also been markedly improved. The cover for the south end of the R.A. housing is streamlined, more modern looking, and easier to screw on. Oh, as with the Atlas, the declination wiring is internal; there is no declination cable to mess with.

Which brings us to the power panel. It’s OK, if on the simplistic side. There’s the now-standard Celestron thread-on power connector, a nice large on-off switch like the one on the VX, and hand control, Aux, and auto-guider RJ-type ports. Unlike on the VX, there is only one Aux port, and like the VX (and CG5), there is no PC port. Luckily, I have Celestron’s (now discontinued) Auxiliary Port Accessory, which adds the PC port so I can connect NexRemote directly to the mount without the use of the hand control serial port (or even having the HC connected).

I screwed the counterweight bar and nut onto the declination assembly, dug up a Celestron 5-amp power supply, plugged the HC into the HC port and discovered the first thing I didn’t like about the CGEM. If I thought the cable on the VX hand control was a little short, I hadn’t seen nothin’ yet. This one was ridiculously short. It was obvious slewing in R.A. would yank the thing out of the holder and leave it dangling by its cord. Luckily, I had a nice coiled extension I bought for the VX from Scopestuff.com’s Jim Henson. I rustled that up right quick. Finally, I placed the VX counterweight on the shaft, followed by the CGEM weight.

Alrighty, then. Before I could get Bertha on the CGEM, she’d have to have a Losmandy “D” style dovetail installed on her belly. I opened that final box. As I’d expected, there were no instructions, just the (very, very orange) Celestron C11 dovetail bar and a little baggie containing four screws. I was puzzled at first, since two screws were long and two short(er), but a little experimentation showed which went aft and which went forward. The short “place-holder” screws I removed served to fill in the last of the screw holes in the OTA left by removing the brackets that had attached it to the fork mount.

No use delaying the inevitable. I hefted the C11, slid the dovetail into the saddle on the mount, moving it pretty far forward so balance would be reasonable—Bertha is even more rear end heavy (sorry, old girl) than Mrs. Peel, the Edge 800. Done, I took a few minutes to just admire the new Big Bertha. That big carbon fiber tube looked finer than split frog hair on the CGEM, and I gotta admit the uber orange dovetail actually added something. I was soon hollering for Miss Dorothy to COME LOOK!

I did a little fine-tuning of R.A. axis balance, placing the CGEM weight near the bottom of the shaft and the VX one about halfway up. Next was rubber meets road time:  power up for the first time. I plugged the power supply into the mount (the connector fit snugly with no need for spreading connector pins, unlike with the VX and CG5) and into the wall, and hit the o-n/o-f-f. I reckon I’ve got used to the Plus HC, which takes longer to boot, so I was kinda surprised how quickly I got “CGEM Ready” on the LCD. We was good so far.

Next thing I do with any new mount is a fake alignment indoors. Which was easy. As I told Miss Dorothy, I was real comfortable with the mount from the start. It truly was just like a great, big VX.  I set the R.A. and declination axes to their “home” marks (which are a little small if’n you axe me), entered the date/time and other usual stuff, and began a two star alignment. The CGEM stopped with Bertha pointing in approximately the positions the two stars would be in in late afternoon. I didn’t add calibration stars, natch, just hit “undo.” The mount responded with a reassuring “Align Success.”

After my fake alignment, I did a couple of gotos. I asked for M31 and M27, and the tube was pointing in roughly the correct places when Bertha halted. The sound? Bottom line is that the CGEM uses servos instead of steppers like the Atlas, and will never be as quiet as her sister mount. That said, the noise level was about the same as the VX—a little quieter than the CG5 perhaps. The mount also sounded assured and powerful, there was no hint of any struggling with the big OTA. That is the short and sweet of the mount’s arrival, friends. If you’d like more details, have a look at the Youtube video below.

Now to wait for darkness. The sky didn't look overly promising. Plenty of cirrus clouds littering the heavens. The Wunderground.com did imply they would begin to disperse at sunset, and that it might even be clear by nine. While waiting for Sol to go away, I got my hex wrenches and transferred the TPI spreader bar from the Atlas tripod to the CGEM, the work of but a few minutes.

I was purty sure that would prevent any stability problems, but if not, I have a set of Celestron vibration suppression pads (they shipped with the NexStar 11 GPS). I could also install the TPI equipment tray on the spreader and load it down with a jumpstart battery or two. The scope seemed solid enough on the mount from what I could tell without doing any of that, but the only true test is under the stars.

When the clouds had thinned enough to encourage me that I wouldn’t be wasting my time, I disassembled the rig and lugged it into the backyard. Verdict? It ain’t that bad. Yes, the mount head is a load, but a bearable one. The OTA? The key is keeping the tripod legs collapsed so you don’t have to lift the tube high to get it in the saddle. That’s jake by me, since I use the 11-inch 99% for imaging. If I want to go visual, the collapsed tripod is fine with an observing chair.

Alignment was anticlimactic. No different than with the VX. Two alignment stars, then (up to) four calibration stars. As per usual, the first star was purty far off, the second was closer, and by the time we got to calibration star 3, it was in the crosshair eyepiece when the slew stopped. One thing that made for an easy alignment was that, instead of a finder scope, I used the Edge’s Rigel Quickfinder. I found I had an extra Quickfinder base in my shop, and it was a no-brainer that it should go on Bertha.

Alignment done, I replaced the 12mm Meade reticle ocular with the 13mm Ethos and had at it. Conditions were not good and were degrading rather than getting better as had been predicted. By 9 p.m., as a matter of fact, we was socked in. That did not prevent me from doing nearly 20 objects, however, and every one of them was well within the field. I didn't just go with easy ones, either. I went after M57, which was close to the horizon, M31 at the Zenith, and objects at all the cardinal points. Only problem was seeing ‘em through the building haze. The mount? Again, just not much to tell. Like a big VX or CG5 in every way.

When the last sucker hole evaporated, I returned Bertha to the sunroom and quitted the backyard for the den and a little cable TV and Colorado Kool-aid. After boring Miss Dorothy with a lengthy recounting of my backyard adventures: “There was M57, no more than 5-freaking-degrees above the horizon. BAM! It was in the eyepiece, easy!”

Was I satisfied? You bet. I hated to jinx it, but this was so far proving to be the smoothest “commissioning period” for a major new piece of astro gear in a long, long time. When I’d calmed down some, I watched episodes of Gotham on the On-demand till my peepers began to close and Chaos Manor South’s resident black cat, Thomas Aquinas, awakened me by tapping on my cheek with his paw, signaling, “Time for you to go to bed, Daddy.”

Tuesday dawned to considerably better weather, and there was no doubt Bertha and her new mount would get a second go. Like Miss D. said, “Don’t want to get caught out down in Chiefland.” Yep, I wanted to make doubly sure all was well, and the way the weather was looking for the next week plus, I wasn’t sure I’d get another chance to use the mount before our CAV odyssey. Yes, there’d be some clear weather, but it would be accompanied by temperatures in the teens. Not exactly Unk Rod observing conditions. After that? Clouds.

Set up went much as before, and so did alignment. What did I learn on this night? It’s better to balance. While the mount didn’t have any trouble moving the OTA to targets with my, er, “casual” balancing, it made a little more noise, sounding more like the CG5 than the VX. I stopped, moved the weights to the places they should have gone in the first place, and realigned.

Following that, the CGEM was noticeably quieter. Gotos? Anything I requested  was—BAM!—right in the middle of the dadgum 13 Ethos or my 16mm Happy Hand Grenade (Zhumell 100-degree eyepiece). What did I look at? Anything apt to show up well in my skies and not too low or behind trees. Probably 25 – 30 gotos before the wind began to blow.

Funny thing about the wind kicking up? It didn’t seem to bother Bertha a bit; no shaking did I detect. A sharp rap on my girl’s rear end resulted in vibrations that died out in just a hair over 2-seconds. I probably will add the TPI accessory tray down at the CAV, mainly because it’s a good place for the mount power supply, the DewBuster power supply, the Mallincam Xtreme’s 12-volt battery, etc., and I suspect that will steady us down even further. Not that More Better Gooder is needed anyway in my judgment.

Any new telescope, and that’s really what Bertha is now, requires a period of adjustment, but I suspect set up will become easier the more I use the rig. I don’t think I will suddenly stop using the VX/Edge 800, muchachos, but Bertha is damned sure going to get out a lot more than she has over the past five years, and that is all I wanted.




Next Time: Down Chiefland Way...

Sunday, January 11, 2015

 

Deforking Bertha


The 64 thousand dollar question for 2015 was, as I told y’all in the New Year's blog entry “What do I do about the C11?”  I’ve had a NexStar 11 GPS since 2002, and I’ve loved her for most of that time, though we got off to a somewhat rocky start, muchachos. When she arrived at Chaos Manor South a dozen years ago, the NS11 skeered me. I was daunted by the size of an 11-inch Schmidt Cassegrain Telescope on a huge fork mount. How in the h-e double L would I get that thing on its tripod, even in alt-azimuth mode, without destroying it, my back, or both?

Turned out not to be as bad as I feared. Unk hadn't yet hit the big 5-0 and was reasonably healthy and strong. While I considered the purchase of Starizona’s Landing Pad tripod accessory to help get the scope properly positioned on the tripod, I soon decided I didn’t need it. With a little practice and the aid of a wheeled JMI case, toting the scope out to an observing field and lifting it onto the tripod was, if not easy, not as much of a challenge as I was afraid it might be.

And, so, it was unicorns and rainbows for me and the NS11, who I soon discovered was named “Big Bertha,” for quite a spell. For ten years. As my fifties ran out and my sixties approached, however, something strange happened. Every fraking time I took Bertha out, it was more difficult to lift her case into my vee-hickle and more difficult to get her up on her tripod. That danged CAT was putting on weight!

‘Course the problem was not the scope, but moi. Each passing year made wrestling with Bertha more of a pain. The result was that I stopped using the scope at our local dark site, reserving her for Chiefland and (occasionally) the Deep South Regional Star Gaze. Three years ago, following an incident where I nearly hurt myself right bad while maneuvering the NS11 in her case down the front steps of the old Chaos Manor South, I began using the scope even less. Once I purchased my Edge 800/VX rig in the spring of 2013, I stopped using Big Bertha altogether.

Which was a shame, since she is such a capable telescope, both visually and for video. I never did much long exposure astrophotography with her; that required hefting her onto her wedge, which was a hell of a job even in my salad days. She could do amazing stuff with the Mallincam Xtreme, however. The countless tiny galaxies of the Herschel Project fell before her like dry leaves before the wild hurricane fly. I missed those crazy deep sky tears down CAV way with my girl Bertha, but what could your broken down old hillbilly of an Uncle do?

As 2013 segued into 2014, I determined to do something to get Bertha back on the road and under the stars again. Thinking part of the problem was the big, heavy JMI wheeled case, I tried a couple of case alternatives. Which were dismal failures. I did develop an easier method of getting the scope in her case into and out of my Toyota 4Runner, but it was easier, not EASY. Leave Bertha caseless? That was harder, not easier. At least I could roll her to the scope in the JMI. Regretfully, I put Bertha out to pasture again.

Oh, how I missed having the C11 on the field with me on those nights when I decided to go visual. Yes, a C8 like Emma Peel, my Edge 800, can do a surprising job on the dadgum faint fuzzies, but come close to a C11? No freaking way, y’all. There was simply no question of me continuing with Bertha the way she was, though. In the course of cleaning out the Old Manse after our move last spring, Unk took a spill and fell on his back on the front steps. Didn't do any permanent damage, but I was stove up for a long time. That little accident underlined that I have to take things easier these days and be more careful, and that precludes waltzing a 66-pound fork mount SCT around.

The all too obvious solution, then? Bertha would have to come off her beautiful fork and go onto a GEM, a German equatorial mount. I hated to do that. Not only were her gotos always spot on from one side of the sky to the other, in alt-azimuth mode she was incredibly stable. And her GPS alignment (I never upgraded to a new hand control) made getting aligned the work of three or four minutes at most. But ‘Twarn’t nothing for it. The fork was the trouble and had to go.

Resolved to defork poor Bertha, the question became “And put her on what?” I considered that for months. I ruled out the expensive solutions, the Astro-Physics and Bisque mounts and the others in that tier. I wanted to do the same things with Bertha on a GEM that I’d been doing with her on a fork: deep sky video, planetary imaging, and visual observing. Any of the high-toned GEMs would be overkill. And Unk is thrifty to a fault these days.

At the top of my list for Bertha was Losmandy’s venerable G11 mount, now equipped with the new Gemini II goto system. After setting up next to a dude using one at last fall’s Deep South Regional Star Gaze, though, I changed my mind. The G11 seemed a mite on the large side for me with that big tripod, and while the Gemini II system had some incredible features, it was, in my opinion, still a work in progress given the way my neighbor sweated over getting aligned and tracking during the star party.

What then? The next obvious candidate was iOptron’s innovative CEM60. This mount is a uniquely designed “center balanced” GEM like the company’s smaller ZEQ25. There’s a lot to like about the CEM60. Its base version (without external encoders) is less expensive than the G11, even when purchased with one of iOptron’s nice-looking piers. Certainly, its payload capacity, 60-pounds, would be more than adequate for Miss B.

Unfortunately, the more I read about the CEM60 on the cotton picking Cloudy Nights and the other astro BBSes, the more I began to believe it, like the Gemini 2, was not quite finished yet, either. In addition to people reporting various QA deficiencies, including some affecting mount stability, the CEM60 currently lacks a multi-star goto alignment, relying on an accurate polar alignment to deliver good pointing accuracy.

That would be something of a killer for me. If all I wanted to do was prime focus imaging, shooting two or three objects—at most—over the course of an evening, syncing on stars near the target and/or doing a little hunting would be acceptable. What I sometimes want to do, however, is image 50 or 100 targets with the Mallincam in one night. For that to happen, goto has to be bang-on every freaking time from horizon to horizon. I believe that, once it matures, the CEM60 will be a helluva mount and an excellent value. I just don’t think it’s there yet.

Well, well, well. What would I do? What would I do? Maybe I already had a GEM mount that would do. I am not talking about my VX or CG5. While I’d observed frequently and happily with my buddy Joey the K’s CG5 mounted C11 over the years, the big OTA is undeniably a handful for the VX/CG5. Not horrible, mind you, but doing video on a breezy night down at the CAV would not be easy if it were possible at all. Luckily, the CG5 and the VX are not my only GEMs.

I also have an Atlas (EQ6), which is a step up. And, its tripod is equipped with the TPI spreader system, which makes it very steady indeed. Replace the Atlas’ Vixen saddle with a Losmandy D type saddle, put a Celestron vibration pad under each leg, and I figgered the C11 would be Real Good on the Atlas. While the mount head ain’t exactly light, it is over twenty pounds lighter than the NS11/fork and less awkward (and dangerous) to carry around.

Only fly buzzin’ around in that-there ointment? The Atlas’ goto has always been fine, but never on a par with the excellent accuracy of the NexStar 11 GPS. The Atlas’ SynScan computer does feature a 3-star alignment, but pointing is still highly dependent on a middling-good polar alignment. Good goto with the Atlas also relies on you—not the hand control—choosing the best alignment stars. Even when everything is right, there may be problem spots, like the area near the zenith.

The Atlas’ goto could always be somewhat finicky, but its quality maybe got worse with the last firmware release for the mount, v3.35. Still more than adequate for prime focus imaging, but for running The Son of the Herschel Project? Probably not. These ruminations on my part concerning the Atlas coincided, however, with big news:  Synta/SkyWatcher had released a new firmware build for the SynScan mounts (which includes the Atlas) designed to fix multiple problems. It also promised improved alignment star filtering. Theoretically, you should now be able to just accept the first stars offered by the hand control—just like with the Celestron mounts.

I loaded up v3.36 and hit the backyard for some tests. The scope on the Atlas would be my venerable 1995 C8, Celeste. At f/10, her focal length would be comparable to that of the C11, which I usually run with an f/6.3 or f/3.3 reducer.

You might not believe it, campers, but Unk occasionally has nights when everything goes right. I polar aligned with the polar scope, using the value for Polaris Local Hour Angle on the HC to dial it in nice and close. I was purty sure this was going to be a good run when the second of the three alignment stars, Deneb, was in the field of the main scope’s eyepiece when the slew stopped. I centered up the third star, Capella, and starting issuing some goto commands.

Everything I requested, from M57 in the west, to M37 in the east, to Fomalhaut in the south, to NGC 457 in the north, to M31 near zenith was in the center of my 20mm eyepiece at 100x. I don’t mean “near the center,” I mean “dead center.” Being a suspicious sort, I returned to these objects several times over the course of the evening, and each was again centered.

As the clouds moved in and I hit the Big Switch, Unk was feeling good. While I had been careful with the polar alignment, that was all. I hadn’t picked special alignment stars, just OKed those the HC offered first: Vega, Deneb, and Capella. I believed we was good to go. All I needed to do was order a replacement “D” type saddle for the mount and a Losmandy style dovetail bar for the scope.

The next morning, I was still on a high about the way the Atlas had performed with the new firmware, but, as y’all know, your old Uncle often quotes the Gipper’s “Trust but Verify.” Sometimes that is for no good reason. Others? It can save the day. Since it looked like we’d get marginally clear skies for a while after sundown, I figgered I’ve give the Atlas one more go, just to be sure.

Didn’t do anything different on this evening. I set the scope up in approximately the same place in the backyard. I did notice when I was polar aligning that I had to move the mount in altitude. Why should that be? I put it down to “whatever” and pressed on. The HC came up with the same three stars as the previous evening. I accepted ‘em, centered ‘em, and got to work.

First up was M57. It was in the middle of the field of the 13mm Ethos I was using. M37? Not so much. It was in there, but off toward the edge. M31? Nuttin’ honey. It was not in the eyepiece. It was not even close to the eyepiece’s field. What the hell?

I started thinking about the polar alignment. Had I aligned on the wrong star? It was just barely dark when I’d done the alignment, and I’ve been known to do my polar alignments on Kochab instead of Polaris under those conditions. How about the goto alignment stars? It was earlier in the evening, and Deneb was up fairly high. Maybe too high? First thing I did was use the hand control’s built in AllStar style polar alignment routine. I wanted to see how well it worked anyway. I had to move a substantial distance, so it looked like my polar alignment had indeed been punk for whatever reason.

Polar alignment redo redone, I shut down and did a new three-star using Capella, Hamal, and Caph. Result? M37 was still toward the field edge, but closer to the center. Same for M31, thank goodness. Indeed, everything I slewed to before the night’s ration of clouds impelled me to pull that accursed Big Switch was somewhere in the field, but usually not anywhere close to the field center.  I broke out the Yell and watched a couple of episodes of Unk’s current fave cable TV show, freaking Bourdain’s The Layover, and decided to do no more thinking about the mount till the next morning.

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This was all beginning to weigh on your pore old Unk. I woke up with the fraking Atlas on my mind. And was still thinking about it as I drank my morning java. The theory I developed was that my initial less-than-sterling pointing was caused by that (supposedly) punk polar alignment. Redoing it helped some, but only some, because rather than using Vega, Deneb, and Capella, which were probably the best stars for that particular date and time, I picked three others. That was my theory, anyhow.

The elephant in the front parlor? While the Atlas’ goto performance with the new firmware can be sterling, it is still pretty obviously more dependent on polar alignment and alignment star choice than my VX or my CG5 are. For the sort of observing I had in mind, it was purty obvious the mount would always be a little too fussy. The VX or the CG5 take a little while to align, but there’s no hassle doing a goto alignment; you just choose the stars the HC comes up with. Polar alignment is never a factor with their goto performance.

“Well, then, Unk,” you might say, “why don’t you just use the EQMOD driver to run the mount. It will allow you to use as many alignment stars as you want and provide dead-on goto.” It will in theory. I’ve had varying success with it over the years, though I know many Atlas and Sirius users swear by it. Last couple of times out (the latest version of) EQMOD would not sync on some stars—which was likely pilot error. I don’t always want to tote a computer into the boonies, though, and even when I do, I don’t want to do anything with it other than just send the scope on her gotos. These days, your Old Uncle finds a hand control simpler to use.

I thunk and I thunk and I thunk, and it soon became evident the solution was staring me in the face and had been for a long time. I needed a larger Celestron GEM. Which one was easy to figger-out. I sure did not need the weight, payload capacity, and expense of the CGE Pro. The CGEM DX was a possibility, but the main difference between it and the standard CGEM now is a huge 3-inch legged tripod that weighs in at 50 pounds. I knew dadgum well I didn’t want to—couldn’t—deal with that. Which left the obvious, the CGEM.

The Celestron CGEM is based on the Atlas/EQ6 and has a similar payload, 40 pounds. The tripod is nearly identical to the one on the Atlas. The big difference other than some mechanical improvements and cosmetic updates? The Atlas’ stepper motors and SynScan handset have been replaced by servo motorss and the Celestron NexStar HC. Which was just what I wanted.

I talked things over with Miss Dorothy, whose opinions in such matters I value highly. She concurred:  get the CGEM. I picked up the phone and called one of my fave dealers, Bob Black at Skies Unlimited.  After a little checking, Mr. Bob found he had one in stock. All I wanted was to get the mount in time for our next Chiefland run, but despite New Year’s Day intervening, it turned out the mount would be in my hands the following Monday, or so the UPS goobers promised. Like all y’all, I want my new astro-stuff NOW, but a few days waiting was actually a good thing. There were a couple of things I needed to buy and there was some work to do.

First off, I needed a dovetail bar, a Losmandy D-type dovetail bar, for the C11 OTA. There are numerous sources for these, including Losmandy and ADM, who produce top-flight, beautifully machined stuff. As has been mentioned a couple of times already, howsomeever, your Uncle is Scrooge McDuck’s brother from another mother, and I didn’t want to spend a hundred dineros or more if’n I didn’t have to.

That in mind, I figgered I’d take a stroll through B&H Photo’s gigantinormous website. They (and Adorama) are my goto photographic gear folks, since they are renowned for their reliability, speed, and good prices. But did you know they sell lots of astro-gear, too? They do, and they had a Celestron D Dovetail for the C11 sure as shooting. For less than 30 bucks. Downcheck? It’s that modern Celestron Orange color, which some of y’all don’t like. Me? The dovetail on my Edge 800 is an orange one and I think it is kinda purty. Off to B&H went my credit card number.

What else? The finder mount that came with the NexStar 11 was an original Celestron non-removable job. Much like what came with my 1995 Ultima 8. To place the scope in the JMI case, the finder had to come off, so JMI provided a bolt on bracket and a new base to make the Celestron rings removable and reinstallable. Worked, but was decidedly non-standard. I went to my small-stuff guys, Agena Astro Products, and got another Synta SCT finder base on the way. Decent price and no shipping charge. Unlike a certain famous west-coast outfit who was willing to sell me the part for .25 cents less than Agena, but then wanted to tack on ten bucks to ship the tiny thing to me.

It was now time for the work. For deforking the NexStar 11, removing the tube from that big fork mount. I am no stranger to deforking C8s, older C8s, but this would be a decidedly different proposition. Not only is the tube of an NS11 comparatively big and heavy, its fork is buttoned up with plastic covers. I did some browsing on the web and reviewed a couple of folks’ instructions for DOING THE DEED.

Early one morning, I went out to the shop, manhandled Bertha out of her case, and went to it. You can hear and see the details in the video linked below, but to sum up? I padded the work area well with rugs and towels in case something slipped, and worked slowly and meticulously. Nevertheless, as you’ll learn in the video, it actually took longer to get the fork back together perfectly once the OTA was off than it did to take it apart (I plan to sell the fork, the JMI case, the tripod, and my big wedge on the Astromart soon, so I needed to restore the fork to its original condition).

With Bertha sitting on my workbench, all that was left to do was plug the screw holes that resulted from removing the fork brackets from the tube. Luckily, I had a bag of Celestron “place holder” (short, that is) screws. Once that was done and I’d essayed a little cleaning of the OTA, I gotta say Miss B. looked young again. The funky old fork was beginning to make her look like a relic from a bygone age. Now she just looks spiffy with her pretty carbon fiber tube and all.

There was one final piece to fit in the puzzle:  a dadgum case. I certainly didn't intent to continue hauling around that huge JMI container now that the fork was history. Luckily, once the fork is out of the picture, there are lots more options. The one your Unk exercised was, naturally, the cheapest:  a big Sterilite (Rubbermaid clone) container from Wally-fraking-world with some foam from their craft department for padding. Just over twenty bucks as opposed to more than a hundred for a custom C11 OTA case.

Finally, muchachos, I removed the old finder shoe, bolted on the new one from Agena (which arrived in two dadgum days), installed Bertha’s original Japanese finder (nice) in a Synta style ring mount which would fit on the new base. And began waiting anxiously for the mount. So, what happened when the CGEM arrived? That, my friends, is a story for next time, since we are plumb out of time and space for this Sunday.




Next Time: A CGEM Comes to Chaos Manor South...

Sunday, January 04, 2015

 

Destination Moon Night Nine: Sometimes You Squeak By…


With stormy weather predicted to be on its way, I thought I’d better get out and take more lunar images while I could, muchachos. Unfortunately, while not forecasting dire conditions for the evening in question, the weather goobers agreed there’d be “some clouds.” Worse, Seeing on the Clear Sky Clock was transitioning from dark blue squares to light blue ones. I thought it was still worth a shot, though. The weather gurus are saying we’ll have a cool and wet winter, so there’s no telling how many more chances I’ll get at Miss Hecate before spring.

Last time out, I’d gotten a little rushed and had to finish set up in the dark. Darkness is now coming on in a hurry, and it had snuck up on me. That wasn't my only mistake.  I'd decided not to install the DewBuster dew-heater system on the C8’s corrector that night.  Naturally, it became obvious not long after sundown that it was going to be a dew-heavy evening, so I had to waste more time getting the heater installed.

I'd also forgot to hunt up my JMI motofocus motor, and had to scramble to get it on the scope, too. Overall, Night 8 had a flying-by-the-seat of my pants feel. That’s understandable, I reckon, since Destination Moon had taken a few months off, but I didn’t like that feeling and resolved to do better on Night 9.

Ha! This is Unk we are talking about. I did at least start set up an hour before sunset and get my 1995 C8, Celeste, on the VX mount and heater strip on her corrector before dark. I was feeling right proud of myself was standing there fat, dumb, and happy in the gloaming, staring up at beautiful Luna. Till I realized I’d forgotten to rustle up the dadgum Motofocus again.

I retrieved the widget from the house and installed it on the C8, snapping the motor over the SCT’s focus control. What’s a Motofocus, anyhow, and why do I use one? A recipe for out of focus Solar System images? Twitch the focuser and walk back to the computer to observe your results. Not only will focusing cause some shake on even firmly mounted scopes, shaking that may continue for some time at f/20 or f/30, you may forget which way you turned the focus knob the last time when you go back to the scope to tweak some more. It’s a pain, and you apt to settle for less than perfect. Sitting and watching the image on the computer and focusing with a wired remote control is mucho bettero.

There are two ways to do that. One is with a Crayford focuser on the rear cell. These are similar to the focusers on (some) Newtonians and refractors, and focus by moving the camera back and forth instead of the SCT’s mirror, which is what the normal focus control does. That’s good in that it eliminates focus shift. The SCT’s moving mirror system causes the target to move back and forth in the field because of slightly loose tolerances between mirror and baffle tube. That is not a problem at f/5 or f/10, but at f/20 or f/30, which most of us use for Solar System work, it may move the crater of interest right out of the camera’s view.

A Crayford focuser equipped with a motor is probably the best remote focus solution if you use a refractor or Newtonian or if you are an SCT owner who only want to use the focuser for planetary/lunar work. Unfortunately, one causes problems for deep sky imaging with a CAT. The extra back focus required by a Crayford may make it impossible to bring your camera to focus, at least if you have a reducer in the imaging train, as you probably will with an SCT. Motorized Crayfords also tend to be more expensive than your parsimonious old Unk likes. Enter the JMI Motofocus.

“Whats they-at Unk?” Well, I’ll tell you, Skeezix; it is a lot like JMI’s old Motodec. That blank look on your kisser tells me you weren’t around in the days of non-goto fork mount SCTs that required add on motors for declination guiding. To make that long story short, then, the Motofocus is a motor that snaps over the SCT’s normal focus control (or, actually, a replacement focus knob and collar JMI includes with the Motofocus). There’s also a cable and a two-button remote. Push the buttons to focus one way or the other (holding one down for several seconds conveniently speeds up the motor) as you can sit at the PC.

Yes, there will be image shift, but even on my 1995 Ultima 8 OTA it is bearable. And it is just so cool (and effective) to be up on the deck with the PC and watching the screen to focus. I did have to spring for two extension cables for the Motofocus’ uber-short cord to allow me to do that, but even figuring in the extra cost of those from JMI, the price was still lower than for a motorized Crayford. If you are less lazy than Unk, you can even fabricate your own extension cords, and not have to pay the extra fare.

With the Toshiba laptop up and running, camera plugged into the USB, and computer plugged into the VX mount’s serial port, I turned a critical eye to the sky. Didn’t like what I was seeing, y’all. In late afternoon, it had been clear as a bell. An hour after sunset, there were bands of thin cloud approaching from the west, and the humidity had spiked way up. The DewBuster would deal with the resulting dewfall, but there wasn't nothing it could do about fog, and it felt like that was a distinct possibility.

Oh, well, wasn't anything on the gull-dern boob-tube anyhow; might as well give it a try. I fired up the VX and essayed a 2+4 goto alignment, an AllStar polar alignment, and, finally, a second goto alignment, since I’d had to move the mount a fur piece in altitude and azimuth during polar alignment. I wanted to use my fave Moon software, Virtual Moon Atlas, to goto craters and other features, so I needed not only the mount's tracking, but also its goto to be spot on.

When all of that was done, I took another look at Diana. Those dratted clouds had moved from west to east and would soon be covering the gibbous Moon, who was hanging high in the east and, for the moment, shining brilliantly as she approached 11 days of age. Time was a-wasting. Unk got on the stick, focusing up on Copernicus on FireCapture’s display. To the extent I could focus. The image was swimming like crazy as the outliers of the clouds began to impinge on Luna. I synced on the crater in VMA so my gotos would be good, but wondered if I was wasting my time given the lousy images on the PC.

I was tempted to just call the whole thing off, but sometimes the images you see in real time onscreen can be deceiving. Sometimes finished, processed images on nights like these can be—if not perfect—surprisingly acceptable. I was feeling like I should stop dawdling with Destination Moon and get ‘er done, so Unk kept on keeping on.

While I gave y’all the rundown on my equipment setup last time, I didn’t say nothing about camera settings in FireCapture for the ZWO, and some of y’all have asked about that. I keep it simple. Gain is at around 60, which gives plenty of brightness, but keeps noise down. Exposure? I aim at holding the histogram to 60%, and adjust the exposure with that in mind. What I was taught back in the early webcam days still maintains:  aim for an image slightly dimmer than what you think looks best. That will keep your frame-rate up and the chances of overexposing highlights down.

How long do I expose for? I generally find 1000 frames, which I can get in a little over 30 seconds at the camera’s highest resolution, will produce enough good frames for a decent picture under reasonable seeing. It will also yield reasonably small .avi files. Keep in mind, though, that I am on the Gulf of Mexico coast where seeing is often flat-out excellent. If you live in a place where the air is less steady, you will need more frames for a sharp finished image.

That our seeing is often top-notch is an advantage to living down in the Swamp. Disadvantage? Despite having a few nights thus far this fall where the temperature dropped below 32F (unusual for autumn here), the dadgum skeeters are still around. All it took to bring ‘em back was nighttime temps in the 60s and high humidity. They were biting the hell out of me right after sunset. I trotted back inside, got a lighter, and fired up a citronella candle, which kept the biting devils at bay (mostly).

It was then, I thought, time to get going. That’s what your silly old Uncle gets for thinking.  The thin clouds that had formerly only been impinging on the Moon were now covering her shining face. All I could do was cool my heels, occasionally re-centering Copernicus on the monitor with ASCOM’s little onscreen hand control, and fuming.

After half an hour, the nasty clouds drifted off, and it looked like I would have a OK if not overly-steady hour or three. What did I do in that time? I journeyed up and down the terminator, snagging features that didn't show as “Imaged” in the Notes field in Virtual Moon Atlas’ info window.

Gassendi

I thought I surely must have already imaged this magnificent formation, but Virtual Moon said “no.” Hokay. Click on this big crater on the chart, mash the “goto selected” button in VMA, and away we went. While the VX’s goto is amazingly good, at f/20 with a 1/3rd inch camera I generally have to do a little centering, but that was OK. If the features were off screen after gotos, they were just off screen and always in the same place and it was easy to line things up with the ASCOM HC direction buttons.

Lying on the shores of Mare Humorum, this big (111 Km.) crater is dang sure something to see. It's flat-floored with a double-peaked, rounded central mountain and high, terraced walls. Those are not the things that draw your attention, however. What does that is the large craterlet, Gassendi A, which has intruded on the main crater’s northern rim. It is big, 33Km in diameter, and is what in part gives Gassendi its distinctive look.

What makes Gassendi even more recognizable is the series of rilles running every which-way across its floor, Rimae Gassendi. There are a couple of nice small craterlets too. While this youngish crater—it dates from the Copernican Age (1.1 billion years ago to the present day)—is almost perfectly round, it looks somewhat oval due to its position out toward the Moon’s limb. I’ve been admiring Gassendi since I was a sprout and never have gotten enough of its stark beauty.

Clavius

OH. MY. GOD. Freaking Clavius base! Even before 2001: A Space Odyssey came out in ’68 I knew all about this crater, one of the most interesting and beautiful on the entire Moon. I double checked with VMA, but, surprisingly, like Gassendi I hadn't visited this one yet for Destination Moon. Not that this was the best night to image Clavius. When the clouds had first cleared off, the seeing had improved some, but now it was getting worse again. Nevertheless, I shot a couple of sequences, hoping for the best.

This enormous 225 Km. walled plain would be impressive on its own, but what makes it a real standout is the detail, mainly the many craters large and small that cover this old (Nectarian, 3.92 billion to 3.85 billion years ago) feature. And, particularly, the arc of five craters beginning with Rutherfurd, which has disrupted one of Clavius walls, and continuing with, D, C, N, and J on its floor. What makes this especially photogenic is that the craters are lined up in order of size, going from 55Km. (Rutherfurd) to 12Km. (Clavius J). There is no better lunar attraction for telescopes of any size than Clavius.

Le Verrier and Helicon

These two smaller craters (20 and 25 kilometers, respectively) are set all by themselves in Mare Imbrium about 235 kilometers from the center of Sinus Iridium. Nearly alone in the relatively bare area, both craters look young and sharp, but they are not really that fresh. Le Verrier dates from the  Eratosthenian (3.2 billion to1.1 billion years), and Helicon from the Imbrian (3.85 billion years to 3.2 billion years). Of the two, Helicon is the most interesting. There’s a system of ridges on the floor that form a distinct “U” shape around the low central peak.

Fontenelle

On the shores of Mare Frigoris, Fontenelle is an interesting looking crater with a size of 38 Km., making it easy for the smallest scopes. It possesses a flat lava-filled floor, a small and rounded central peak, and several rilles, which are barely visible in my image. While it dates from the Lower Imbrian Age, 3.85 billion to 3.8 billion years, this feature is fresh appearing and stands out well.

Philolaus

This one lies 311 Km. southeast of Fontenelle and is a younger and larger formation. It is 71Km. in diameter and dates from more recent Copernican age. In addition to high, terraced walls, Philolaus features a double central peak and a rough-looking floor. It is almost centered on a larger and nearly erased crater.

Birmingham

Talk about “nearly erased.” Birmingham, a large, 93 Km. crater—or what’s left of it--is old, dating from the Pre-Nectarian 4.55 billion to 3.92 billion years ago, and looks it. All that is left is portions of what must once have been impressive walls and a flat craterlet-wrecked floor. The most noticeable feature is two adjacent craterlets, G and H. As a youngun, I felt proud my state’s largest city was represented on the Moon, and was dismayed to learn Birmingham was actually named in honor of a 19th Century Irish astronomer.

Lansberg

The seeing, which had been tending to “worse,” suddenly got much worse, and Unk sat stewing for about fifteen minutes, trying to decide whether to pull that accursed Big Switch or not. Then, the the air began to steady down again, reverting to the merely “stinky” from “putrid.” On to Lansberg (a.k.a. “Landsberg), then.

With neighboring Reinhold, this is a pretty pair of craters. Lansberg itself is impressive, with a fresh look that betrays its considerable age; it dates from the Upper Imbrian 3.8 billion to 3.2 billion years back. At 40 Km. and with a position just far enough from mighty Copernicus so it catches your attention, Lansberg is awesome. It has high terraced walls and a flat floor dominated by a high central peak. There are also craterlets, but they are tiny.

Hortensius

Moving to the north from Lansberg, we run across Hortensius, a medium-small 15 Km. crater washed over by one of Copernicus’ rays. On this night, much of this young (Copernican) crater was in shadow, but there’s not much to see beyond its sharp, perfect looking form anytime. There are steep slopes and a small, flat floor and that is purty much it.

Vitello

My luck and the seeing holding in at least temporarily, I was off to the south and the sands of Mare Humorum for a quartet of craters. Vitello is a nicely detailed 41 Km. feature with high walls and a lumpy floor. In addition to those lumpy hills, there are craterlets, a smallish central peak, and a rille system that is just barely visible in my image.

Doppelmayer

Despite having seen better days, Doppelmayer is still noticeable and impressive. It is 65 Km. in diameter and was formed in the Nectarian days. There’s a jumbled and rounded looking central peak and a series of hills in semicircular lines. “Semicircular” because the side of Doppelmayer facing Mare Humorum has been flooded by Mare lava and has been almost totally obliterated.

Lee

Stationed between Vitello and Doppelmayer, Lee is in even worse shape than the Doppelmayer. What is left of this 41 Km. Nectarian feature is a little more than 180-degrees of contiguous walls.  There are some hills and rough ground along the surviving walls opposite Humorum, but that is all.

Ramsden

Everybody in my generation of amateur astronomers knows the name “Ramsden,” as in Jesse Ramsden, the 18th Century astronomer who invented the simple Ramsden eyepiece, which was all the poorer among us, like li’l Unk, could afford back in the Day. This is his crater.

Ramsden is an oddly shaped 25 Km formation with a slightly oblong appearance. Otherwise? Besides the two craterlets, one that’s intruded into one of the walls, and one nearby, the most interesting thing here is the rille the crater’s formation disrupted, Rimae Ramsden, a double line of rilles with the crater smack in the middle of their length.

Pitatus

Shortly after I finished with Ramsden, the seeing, never good, began to get dramatically worse again. However, Unk was on a roll, and rolled on anyway. A little unwisely as you can see from the result. Anyhow, Pitatus on a good night is an astounding formation—a big crater with a flat, dark floor and a shape much like that of Plato. There’s a rounded central peak and numerous craterlets, but all I picked up was a bland floor with a couple of brigher spots and a blur of a central peak. This is one I would like to revisit. Pitatus is 98 Km. across and was formed in the Nectarian Age, 3.92 billions to 3.85 billion years ago.

Gauricus

Is an old crater, from the Pre Nectarian time and the major impression I have of it is “rounded and soft.” Especially on this night when the seeing was making everything look soft. This 80 Km. feature is just barely with us; it’s walls have been eroded away and slammed by many impacts. The most obvious feature of the flat floor is a ghost crater, or a pair of connected ghost craters, Gauricus F.

And that, as they say, was that. The seeing went south even moreso, and your old Uncle was ready to shut down and warm up from the chilly mid 60 temps. As is my usual practice, I didn’t even look at the .avi files much less process them once I was back inside; pictures always look better, or at least less depressing, in the morning. No, it was the dadburned Yell and an episode of Arrow I’d missed on On-demand.

The next day as I was converting the raw files to normal .avis (“Debayering” them), I was heartened that they didn’t look nearly as bad as I expected. Oh, they were not masterpieces, but all except the shot of Pitatus and Gauricus had some detail to give up, which they did after a run through Registax’s wavelet filters.

One more good thing? After I finished stacking and sharpening the evening’s haul, I did a little playing around with that new stacking program, Autostakkert, which I mentioned to y’all that I had not been able to get working right. As I expected, it turned out to be pilot error (so what else is new?). I am all het up give it a go when Night 10 of Destination Moon comes ‘round, muchachos. For now, though, Luna is gone and it is time to hit the deep sky again.

Total Thus Far:  100 Down, 200 to Go…

Next Time: Deforking Bertha...

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