The Starry Night, 144

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Just Like Old Times

My first "real" telescope was a 60mm refractor. So's my next one.

It's been a busy few weeks, astronomically speaking, not that you can tell from what you've seen here. I've got a research project on full boil for the first time in ages. I'm not quite ready for show and tell about that, but there are some spectacular photos to come. I've discovered Dithering and Drizzle (not the 8th and 9th dwarves as it happens) to help quiet the noise in my deepest images. I've also had to break out the water cooling hardware (and a new, more potent 12v water pump) to keep the chip temperature down where I want it.

Last month, Astronomics announced the renewed availability of the 65mm AT65EDQ, a short-focus, highly corrected refractor for about the same price as a top-shelf eyepiece. I took a look around to see how well the 'scope illuminates a full 35mm frame and found many spectacular examples. With rudimentary care (and good flats), it should be just fine. There was an issue with early models involving a pinched corrected lens at low temperatures, but it's supposedly a thing of the past and easily fixed if it does happen (go to YouTube and check it out). I placed a pre-order in response to an Astronomics email and am trying to be patient.

This tiny OTA will be much smaller and lighter than any other instrument in my kit (rivalled only by the Orion ST80 which I use as a finder and guider, so it doesn't count, despite it being my take-along optic in Australia). The AT65 should be ideal for traveling, especially on casual imaging campaigns or when the trip is not 100% dedicated to about astronomy.

I expect its image scale will be forgiving of my usual seeing and tolerant of field-quality polar alignment and G11-caliber tracking. The objective is an F6.5 triplet built around an FPL-53 high-dispersion element, so I expect excellent color correction. It incorporates a Petzval (or Petzval-like) field-flattener as a 4th element, so I expect it to be razor-sharp to the edges of the field, too. It's really quite the refined package. The focuser is said to be solid and smooth and to preserve focus when rotated. All in all, I'm thinking I can put this on the G11 with the 6D behind it and produce some excellent work with comparatively casual preparation.

As luck would have it, almost as soon as I placed a pre-order for the OTA, I stumbled onto a used LVI SmartGuider 2. See way back for my unhappy experiences with the original SmartGuider which does not play with my early Losmandy electronics. With the included "MGA" adapter, the newer model does, and it offers a couple of very significant advantages over my other standalone guider, the uber-reliable but big, power-hungry, Peltier-cooled SBIG ST-V. The ST-V is hard to beat in the back yard, but for RV use, it's pretty daunting in terms of space and power and preparation. I think the G11 and the LVI-2 guider, together, will draw about a third of the amps that the ST-V needs by itself, and maybe even less than that.

After plugging up the LVI and confirming that it seems solid, I ordered a Canon "reflex cable" so the guider can control the 6D and modified 50D. (The LVI is made in Italy and the new North American distributor is Steve Mallia of, but my cable is coming from Adorama's old stock because of a shipping snafu at Steve's place; we enjoyed a few emails after I abandoned my shopping cart when an accidental $60 shipping charge got hung on it; that's fixed now if you need an LVI or any accessories.) Anyway, I didn't see much point in using camera control cable instead of my usual remote releases and with integrated intervalometers until I saw that the LVI can dither. For that, it has to know when the shutter is open and when it's closed, so here are advantages after all to letting the guider have some authority over the camera.

I hope the 50mm guidescope that I use with the ST-V collects enough light for the LVI. If so this will be a remarkably compact outfit, but if it doesn't, I can always put the Orion ST80 to work as a guidescope again at a modest increase in heft (mostly for the dual saddle assembly). In short between the AT65EDQ and the LVI-2, I expect to put a lot of older gear to good use. Stay tuned for sky trials when the OTA arrives. In June, I hope. [July, actually, and early trials showed the ST80 dual rig to be absurdly heavy, especially when the extra counterweight it requires is counted.]


6/2/2015. Now add a used Orion X-Y Guidestar Positioner to the mix. It will let me forego 3-point collimating rings and all their fussiness by clamping the ST80 into real tube rings and just shifting the guide camera up and down and all around. I might be able to do the same thing with a 50mm guider. Depending on how bulky the X-Y stage is, that might or might not be absurd. [August: the X:Y stage is nice and compact; the ST80, dual saddle is not; the 50mm guider's field is so wide that the stage will not be needed; besides, the 50mm guider is aimable.]

So four small but worthwhile additions to the kit, all with an eye toward getting up and out from our light-struck, tree-shrouded holler to the cul de sac, to the Blue Ridge, or to the Datil Mountains. Now stop and make some photos. I didn't add an ST10XME, and I haven't bought an A-P 900, 1200, 1100, or 1600, so there's that.


6/9/2015. I took the ST80 and its new X-Y stage out into the sideyard for the first clearish night in a while and tipped it up for a look at Jupiter just to make the crosshair eyepiece would come to focus. It does and with room to spare both in and out. That means I can use the ST80 in this configuration as both a finder (its present role on the 10-inch Newt) and as a guider wherever it's needed-- on the AT65, the R-C, the A-P, or whatever whacky DSLR/lens combination I take a mind to try. Just make some D-sized dovetails with appropriate mounting holes and go itt.


6/16/2015. Extremely hot weather has caused problems with cooling the CCD to -20, let alone -25 or -30 for some very deep imaging. The SBIG-supplied aquarium pump lacks the oomph to get water to the CCD from ground level; the 12v DC pump I replaced it with worked great for two nights, now hums; and the Mach1's RA drive needs some attention -- need to check the tightness of the spur gears, grease it, and maybe run Pem-Pro to make sure all is as good as it can be. I'm getting excellent tracking for a few minutes, then a big jump followed by more excellent tracking.


7/04/2015. I remeshed the R.A. motor. Also opened the gear cover to make sure all was working as it should be. I believe I got the gears back to their original positions, but it matters little since I noticed that I've not been using periodic error correction anyway. I've downloaded a trial version of PemPro and will, sooner or later, recalibrate that feature. I also want to try out its polar alignment features. But it is too hot and hazy and I am not inspired to get out there and mess.

I've also ordered a used sleeping bag and a second ball head to use on the iOptron SkyTracker. Both were inspired by hearing from Linda and Tommy Taylor about a Chaco Canyon reunion in summer. Maybe, maybe... I would love to get back out there. The head and appropriate bolts came from Amazon in 36 hours or so; the two heads are now joined by a steel plate drilled to offer a variety of placements. Takes a few minutes and no tools to go from single to dual mounts on the SkyTracker and I see no reason to think it will not work just fine.


7/12/2015. The dual mount on the SkyTracker looks like a complete success [for Arnold Schwarzenager, maybe]. Now there are a couple of 10-lb Meade counterweights en route (from a classified ad by Rolando Chavez on CloudyNights) for use on the Giro and if needed on the old Meade LX55 I just cleaned up. I'm still trying to get clear what will ride what where and what pieces need to be stashed with what...

14, 24, 85, 135, 180 etc
AT65 (unguided)
AT65 guided
AT65 guided
10" F4 Newtonian
6" F5.9 (visual)
5" A-P
SBIG or STV/50mm*
10" R-C
SBIG or STV/ST80?*

* ETA 8/13: the asterisks mark guiding kits that will likely be supplanted by a low-power computer running PHD and a 50mm guider carrying a Meade DSI. When I resurrected that kit to try to lighten the AT65EDQ / ST80 outfit, it worked really well -- pending the right computer to make it practical in the field. The ability to use the same guiding kit at home and out yonder would be very reassuring.

Here's how it breaks out today:

Gear to be stashed in RV.
   G11, Losmandy dual mount, LVI-2, Giro, 10-inch Newt, 6-inch Achro, counterweight(s) for Giro, counterweights for G11, one Gitzo tripod, Losmandy tripod, one Linhof, big batteries.

Gear that stays in NC.
   Mach1, ST-V, 50mm guider, 10-inch RC, SBIG everything, Dob, LX55 with counterweight(s), one Linhof, other Gitzos, Kendrick battery pack.

Gear to be routinely transported to and from the RV.
   ST80, AT65, SkyTracker, Canon bodies & lenses, intervalometers, lightest Gitzo, notebook.

You probably don't need another small guide scope for the G11 though it's tempting to think that when shooting with the AT65 on the G11, it would be useful to put another camera on the mount for the ride. But guide it with the ST80 anyway; if you want a wider lens shooting at the same time, put it on the SkyTracker. Only the AT65 and 180mm Nikkor combination might benefit from a small guider and we kow the SkyTracker carries it just fine.

Because it's never too early to think about the eclipse: put the 10-inch Newt and AT65 on the G11. Tracking is not an issue. Put the 6D behind the AT65 and another full-frame body behind the 10-inch (the 5D if nothing even better is around). Put the 50D on a tripod with a wide-angle lens for landscape stuff. Strobe and remote trigger on 50D? Planning is everything; nail the custom white balance.


Time warp: 8/15.

I set up a new-to-me very low-power netbook (an Asus 1101HA-MU1X-BK) to handle astrophoto guiding duty. I had to install the newest C++ runtime library which required updating XP SP2 to SP3. Then the guiding software, PHD2, needed the ASCOM library and the current version of that required both NetFramework 3.5 and 4.0. Then PHD2 ("Push Here Dummy" v2.5) installed without complaint. Piece of cake. Now let's see if the computer can really guide all night long,or, what amounts to the same thing, how big a battery it needs to do that.

The 50mm / DSI / PHD combo works great on my Dell 820, a massive honkin' notebook that works great for solar imaging (fast capture rate) and anything else where AC line power is plentiful. The little Asus Aspire One finally gave up the ghost and won't power up; the new-to-me Asus was $65 on eBay including case and charger.

DeWalt flat-top modular toolboxes will hold the gear. The one "deep box" currently holds the AT65EDQ and guider with DSI mounted with lots of cables and electronics in the tray on top. I want to put either the AT65 etc or the computer in a thinner dedicated case that clips to the top of the deep box. If there's room for a small battery in the deep box, better, else the Kendrick has its own softpack. For RV use, the battery is already aboard.

And now working through TeamViewer10's configuration since Access Remote PC is out of business and I can't find my registration key. Dang!


Except where noted, deep-sky photos are made with an SBIG ST2000XM CCD behind a 10-inch Astro-Tech Ritchey-Chretien carried on an Astro-Physics Mach1GTO. The CCD is equipped with Baader wide- and narrow-band filters. The internal guide chip of the CCD most often keeps the OTA pointed in the right direction (I'll let you know when an OAG or guidescope takes its place). Camera control and guiding are handled by Maxim DL 5.12. The stock focuser on the AT10RC has been augmented with Robofocus 3.0.9 using adapters turned on the lathe downstairs. A Canon 6D and a modded 50D find themselves mounted on an Orion 10" F4 Newtonian or carrying widefield glass on an iOptron Skytracker. Beginning in May 2013, PixInsight has taken over more and more of the heavy lifting -- alignment, stacking, gradient removal, noise-reduction, transfer function modification, color calibration, and deconvolution. Photoshop CS4 et seq and the Focus Magic plugin get their licks in, too.


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                   © 2015, David Cortner