Sunday, July 06, 2014
Revenge of the Return of the Denkmeier
How was the sky looking last Saturday afternoon, muchachos? Not so hot, if not as bad as it did the Saturday before. One of my favorite observing weather predicting tools, Scope Nights, had gone from showing the first part of the evening as “good,” to indicating the whole pea-picking night would be only “fair.” Fair was better than “poor,” howsomeever, so on your cockeyed optimist of an Uncle pushed.
It wasn’t like I planned to lug a ton of gear out for a Mallincam run. As you learned last week if’n you were paying attention, I wanted to get my old Denkmeier Standard binoviewer out of mothballs and give it a spin at the Possum Swamp Astronomical Society dark site. While I found my plans growing a little more ambitious than that as I sat around the New Manse Saturday afternoon and ruminated (“Maybe I’ll do a few dozen Herschel IIs visually. Might even sketch ‘em!”), I intended to keep the gear load-out as modest as possible.
At 1830, I began packing up the Toyota 4Runner. First in was Mrs. Emma Peel, the Edge 800—a major reason for the expedition was to see how the binoviewer and, especially, its StarSweeper f/6 reducer, would function with the Edge. I had some hopes the answer would be “purty good.”
The StarSweeper is a plain vanilla focal reducer. It doesn't flatten the field or reduce coma. It just speeds up the optical system. I didn't expect the field edge to look great with the ‘Sweeper, but I thought it would work OK in concert with the Edge’s built in flattening and coma reducing elements. If it didn't, well, hell, I’d have the genu-wine Edge f/7 reducer with me in the big Plano tackle box that contains Unk’s observing accessories.
What else? Mrs. Peel’s VX mount, of course, but I would run that mount in minimalist fashion. No NexRemote. Not even a serial cable attached to the laptop. Stock hand control all the way. Almost stock, anyhow. The HC cable on Celestron’s Plus hand controls is absurdly short. I’d got tired of that soon after I started using the new mount, and tried to use an HC extension cable I bought many a Moon ago when the CG5 was new.
That worked just fine—till I began getting dadgum “No Response” errors. Clearly, the old extension was ready for the trash heap of history. I ordered a nice coiled-cord replacement from Mr. Scopestuff, Jim Henson, and it has worked great. If you are going to use the Plus HC comfortably, one of Jim’s cables really is a must.
While I didn't intend to hook the Toshiba laptop to the mount, I brought the Satellite along anyhow. I am not going into the field without a SkyTools or Deep Sky Planner list at my disposal, Cuz. For a brief moment, I thought about just printing out a list, but then the good little angel sitting on my shoulder intoned, “Are you fraking nuts, Unk? This is the dagnabbed 21st Century.” Into the truck went the PC.
Scope, mount, tackle box, and PC was almost it. Big Rubbermaid container with the DewBuster, the inverter, and various assorted astro-junk went in too. So did the Denks, natch. Added my observing chair to the pile, and that was all I carried out yonder other than my little Fuji superzoom camera so I could take a few snaps of the field for y’all. I did NOT throw the “good” eyepiece case in the vee-hickle. As on the long ago Chiefland Star Party night I recounted last week, I declared the SCT a “single-eyepiece-free-zone.” The pairs of GTO Plössls in the case with the Denkmeier would be all I’d need.
Well, that and clear skies, and it looked as if the weather would once again be the monkey wrench in Unk’s plans. That said, while it wasn’t clear it wasn’t that cloudy, either. The Clear Sky Clock was showing generally poor transparency, but it was mostly darker blue squares in the row assigned to “cloud cover.” And not only was I intent on sticking to my usual vow that I’d head to the site if it wasn’t actually raining, my old observing buddy, Max, had called Friday. I’d promised him I’d be at the dark site if the wet stuff were indeed not falling.
So, skeptical as your old hillbilly Uncle might have been, as sundown came on, he turned the 4Runner, Miss Lucille Van Pelt, west for the dark site. The drive wasn’t unpleasant at all—being about 30-minutes closer to the private airfield we use for our observing sure don’t hurt. Especially since our new location means I don’t have to traverse the crazy traffic around the shopping mall on my way out of town.
Seemed like ‘twarn’t long at all before I was pulling onto the well-loved field where, I was pleased to see, Max was already getting his scope ready to go aided by the big yellow tomcat who makes the aerodrome his home. I did note Max and Mr. Kitty were setting up a 4-inch scope, not one of Max’s big guns. Who could blame them? At sunset, the sky wasn’t completely overcast, but it was the next closest thing to it.
“Hokay, I ain’t gonna be a stick in the mud with everybody else setting up scopes but me.” Our fellow PSAS member, Taras, had arrived bearing his big 15-inch Dobsonian, and if he was willing to put together that big gun, the least I could do was get a C8 on a mount. Let’s get ‘er done…
Getting her done should have been smooth. Scope on mount, DewBuster heaters on scope, diagonal in rear port, reticle eyepiece in diagonal, hook up battery and hand control. But it is never easy or simple with your old Uncle Rod. Plugged the mount into the jump-start battery, reached over and mashed the power switch, and waited for the hand control’s sign on message. And waited. And waited. What the hell was wrong now?
Checked my battery connection, and that was OK. Made sure the telescope end of the power cable was firmly plugged in and screwed in place with its threaded collar. Nuttin’ honey. “Well, I’ll be freaking doggoned, what do I do now?” What I did was grab a flashlight, since I’d been doing all this partially by touch in the gloaming.
Shined my light at the mount control panel and what did I see? The power switch was in the o-f-f position. I must have accidentally turned it on when I was setting up, and had actually turned it off when I thought I was turning it on. Oh, well, switched it on and the HC came right up after its usual interval (takes a little longer for it to boot than the old NexStar hand control did). That was not the end of Unk’s troubles, however.
Next step in the get-er-done game would be doing a rough polar alignment, just sighting Polaris through the hollow polar bore of the VX. That’s what I would have done if the northern sky hadn’t been covered in a thick layer of clouds. I waited, but little happened. “Shoot, I know about where Polaris is at this site, and I believe I’m seein’ it wink in once in a while.” I pointed the VX’s RA axis at that spot.
Started the two-star goto alignment, being reasonably careful with the time and other data entries. Star One was Arcturus, but when the mount stopped, it was far from that star. Too far. I often tell goto newbies not to worry too much about how far the initial slew stops from an alignment star. Just center the sucker. But Arcturus was easily twenty degrees from the Quikfinder’s bullseye. That's different. Standing there pondering the sitchy-ation, I happened to glance over my shoulder. “Dadgummit, there’s Polaris!” It was only about, yep, 20-degrees from where I thought it was.
I shut down, re-polar aligned and started the goto alignment over. Star One was still a considerable ways out, maybe because of bum data in the hand control from my previous alignment attempt, but star two, Spica, was, as per normal, just outside the Rigel Quickfinder’s red rings. Calibration Stars three and four were in the field of the 12mm Meade reticle eyepiece in the main scope at 160x when the slews stopped…which spells, “Align Success.” So, my alignment was done if, not in as elegant or quick a fashion as it should have been. As always, what’s an Unk Rod observing run without his silly hijinks and foulups?
Now to the heart of the matter. I removed the reticle eyepiece from the 2-inch William Optics diagonal riding on Emma’s rear port (ahem), I also removed the diagonal’s 2-inch – 1.25-inch adapter and screwed the Denkmeier StarSweeper onto it. Finally, for the first time in years, I inserted the Denk Standard into the 1.25-inch adapter (the Denkmeier Standard binoviewer has a 1.25-inch barrel).
First (new) light? There wasn’t a whole lot to choose from. M13 would obviously have been a natural, but Hercules was cloud city. Slightly lower down on the eastern horizon, little Lyra was almost in the clear, so I mashed the buttons for M57 and away we went.
When the VX’s motors stopped their (fairly) subdued whining, in went my pair of GTO 25mm Plössls and Unk had a look through a binoviewer for the first time in a long, long time. The little oval smoke ring was near the center of the field, hardly surprising for the VX at the modest power of 60x or so. But that was good, anyhow. What was real good, though? Focused up the scope and suddenly that little ring wasn’t just there, it was floating in front of the star field. Sweet.
As I mentioned last time, the faux 3D effect of a binoviewer—the tiny baseline between your eyes isn't enough to show distant sky optics in real 3D—is one of the big draws of these devices. It never fails to impress and amuse me. Sometimes, it’s a little weird, with a galaxy seeming to be in front of field stars, but this view was just right, with M57 sitting in front of those distant suns.
Where to next? Other than a sizeable sucker hole to the southeast, we was almost socked in, now. At least the Ophiuchus and Serpens area, one of my favorite summertime hangouts, was a little more cloud free than the rest of the sky. When Taras hollered something about M5 looking pretty good, I decided that was the nextun.
M5 is one of my fave globular star clusters. I maybe even like it better than I do M13, so I was happy to give it a look-see. Alas, it was but a pale shadow of its normal beautiful self. Despite that, the Denks were doing a pretty good job with it. Decent resolution despite the messy skies. The cluster showed the same 3D effect as M57, if not as strongly. While on the cluster, I tried to get the interpupillary spacing set just right on the Denkmeier, since our next target would tax Unk’s image-merging capabilities.
When the VX stopped, not only was Saturn in the field, there were two Saturns there. Switching out the 25mm GTOs for the 9mm pair, which gave maybe 150x with my optical configuration, just made things worse. I knew not to panic. There was nothing wrong with the Denkmeier, just as there was nothing wrong with my great, big Tachyon 25x100 binoculars when I last used them seriously on the deep sky down in Chiefland a couple of years ago.
I know, KNOW, friends, that for some objects there is nothing like viewing with two eyes. On the above mentioned CAV trip, the big binoculars on their homebrew (kit) mount showed Uncle Rod the summer Milky Way like I had never, ever seen it in five decades of observing. I had to pay my dues to get those views, howsomeever.
Just as with the Denk on Saturn, the Tachyons initially showed me two images, especially of brighter stars. To get past that I had to do what I’d learned to do years back when I first tried my friend Pat Rochford’s old TeleVue binoviewer. First off, I have to adjust the spacing between the two eyepieces, their interpupillary spacing, carefully. Has to be dead right. Then, I have to focus carefully for both eyes. With a binoviewer, I usually focus the left eye with the main scope focus, and slide the right eyepiece in and out till it is sharp, too (the Tachyons have individual focus for each eyepiece).
That is usually not enough, however. I also have to get comfortable (I’d brought my beloved Buyastrostuff observing chair with me on this run for that reason), I have to kinda semi-relax my eyes, I have to hold my head just right, and sometimes it seems like I even have to hold my tongue just right. The combination of all those things invariably leads to success, and on this night I was soon seeing one Saturn instead of two.
How did it look? Right good given the conditions. Initially, the seeing hadn’t been bad, but as more clouds started drifting through and a strong breeze blew up, it became less good. The ringed wonder was sharp, with Cassini’s like a knife-edge, but I didn't really get a look at the Crepe Ring, and detail on Saturn’s disk was barely there.
After Saturn, I went back to M5 to see how it would be at 150x, but at that power it was just too dim given the layer of haze, and I soon decamped for M80. The little globular in Scorpius was more in the clear than anything else at the time. How was it? Good and bad.
I was surprised the Denk was showing a little resolution in this small, tight globular at low power (I’d gone back to the 25mm eyepieces), and that was cool. The glob looked as good, frankly, as it usually does under far better conditions with an 8-inch scope. And yet…and yet… The field of M80 is fairly rich, and I couldn’t say I was that happy with the way the stars looked out on the edge. Oh, they was OK, but they weren't perfect. I guess I’ve just got spoiled by the perfect stars in the barefoot Edge 800 or the Edge 800 and Edge f/7 reducer combo. If I use the Denk with the C8 next time, I might see if it will come to focus with the f/7 rig.
“If?” Yep. I am going to say rat-cheer that the Denk is much more pleasant to use in my NexStar 11. It isn’t because of that scope’s greater light gathering power, either. It is because I habitually run Big Bertha in alt-azimuth mode.
When I was slewing back t M5, the tube “rotated” as a tube will do as an equatorial mount moves across the sky. The problem was that I hadn’t cranked down the William Optics SCT-style diagonal quite firmly enough. As I watched, the diagonal with that big binoviewer in it flopped down. I was there to grab it, and the Denk didn't threaten to come out of the diagonal and hit the ground, but Unk’s withered little heart did skip a beat or two, nevertheless. In an alt-az mode SCT, the binoviewer doesn't rotate and tend to twist loose.
I took a look at Mars after I calmed down, but it wasn’t much, even in the 9mm GTOs. It is well on its way to being tiny again, the seeing now sucked, and Unk’s poor eyes—which his eye doctor has informed him will need cataract surgery in a year or two—just ain’t up to the task of prising detail out of an uber small angry red planet no more.
I had a look at M4, the loose globular cluster over in Scorpius, and it was purty nice. Back to Saturn for a minute. One last look at M5, and I thought it might be Big Switch Time—because of the sky and nothing else. At this time of year, I would normally have been miserably damp with dew and bitten to hell and back by skeeters, but not tonight. The steady breeze kept the dew light, and maybe also put the kibosh on the bugs, though I suspect my Thermacell, which I’d lit off the second I hit the field, had more to do with that. It was only 10 in the p.m., but the sky was getting worse by the minute, and Max and Taras agreed with me we might as well give in to the inevitable.
By 10:20 I was on the road home, and shortly before 11 p.m. I was tucking Miss Van Pelt in in the carport of the New Manse. Svengoolie was over, dernit—he'd showed another of Unk’s faves, Brides of Dracula—but all was not lost. I opened a Kolorado Kool-aid, and, after a little cable surfing, found a replay of the evening’s Braves vs. Phillies game. Watching the Braves put a hurtin’ on the Phillies almost made up for Unk’s semi-skunking on the observing field.
When will I get the Denks out again? Soon, I hope, but there is a lot on my plate right now, including checking out the Mallincam Micro. I also want to get back to work on my Messier Album Project. There is a CAV run for me and D. in the offing. I am planning to do considerable sketching of the brighter Herschel 400 II objects. I need to get Old Betsy, my 12-inch Dob, cleaned up and operational after our move. I also want to (finally) figure out how to interface Bets’ Sky Commander DSCs to SkyTools 3…and—well, what I want to know, muchachos, is how in the hell did I find the time to do astronomy before I retired?
Next Time: Wired Betsy...
I enjoyed these last two posts Rod. I purchased an inexpensive Williams Optics Binoviewer a while back. But I only used it a few times before I discovered the world of the Mallincam Extreme. Needless to say, the binoviewer has been collecting dust. But you have reminded me of those 3D views. I will have to try it again soon. Thanks.
Nice post, off topic but would like to see a future review of the many Mallicam units now available... its getting confusing! HowardPost a Comment