Wednesday, January 09, 2008
Down Chiefland Way with EQMOD
Actually, this entry ain’t really about the Chiefland Astronomy Village, though those of y’all who’ve been reading this blog for a while know the high regard Your Old Uncle Rod has for the skies—and the people—of CAV. No, this is really about the new telescope mount that has come to stay at Chaos Manor South, the Orion Atlas EQ-G. Well, that's not quite right, either. It’s really about an amazing piece of astronomy software, EQMOD, which turns a good mount into a great one.
In recent times I’ve begun to drift away from the fork mounts I’ve used for the better part of three decades. That process began with the arrival of the Celestron CG5 at the ol’ manse three years ago. Despite its low price, this German Equatorial Mount worked impressively well, displaying surprising go-to accuracy (at least as good as the NexStar 11). It also seemed easier to use for imaging. The silly little thing took picture after autoguided picture with an SBIG camera. Couldn’t ask for more? Actually, I could.
One weekend I was down at Chiefland with the C8/CG5 and a Stellacam II, traveling light. I was having a great time videoing the deep sky…until. The wind came up. With a good wind (not quite a gale but strong enough), the CG5 began to shake like a sinner in the hands of Elmer Gantry. Removing the C8’s dew shield helped some, but not quite enough. Despite the fact that this was the only time I was totally skunked by the CG5, I decided another GEM for the C8 was in order. Something with a little more payload capacity. At least for those times when I wanted to do long-exposure prime focus imaging.
What to choose? I eliminated the high-priced spread, the A-Ps and Bisques, right off the bat. I do dream of a Paramount occasionally, but that will wait for retirement--if then. The less expensive gear seems more my style, and part of my enjoyment is seeing what I can get out of "simple and cheap."
Next tier down? Even the Celestron CGE and the Losmandy G11 seemed a mite rich for my blood at this juncture considering the “huge” amount of spare time I have to actually observe with the C8, much less do astrophotography. Vixen Sphinx? In my opinion, that is getting into the “too-light” range. I also have some doubts about the usability of Vixen's Starbook controller. Big doubts.
Which left the Synta EQ6 SynScan go-to (a.k.a. the Atlas EQ-G for us Americans, who have to buy it badged "Orion"). This looked to be a nice, big (and heavy at 40 plus pounds for just the GEM head) mount for an impressive price, about $1500.00 with a go-to hand controller from the U.S. distributor, Orion. I chose the $1500.00 version with the HC despite the fact that the identical (including electronically) mount is available without the hand control for 300 bucks less. This would have been a viable option for me, since, as you'll see, I didn’t plan to use the HC all the time—or most of the time—for gotoing. I did think it would be nice to have the HC for those occasions when I didn’t want to carry the laptop and EQMOD into the field.
|EQMOD with settings opened...|
When the Atlas arrived at dear, old Chaos Manor South, naturally so did the clouds. I did have the opportunity for a few outdoors tests after Christmas, but these were limited. Most of my testing was done in the living room, but allowed me to check that both the mount and EQMOD seemed to work fine. There was one small hiccup: the DC power cable made a poor connection with the mount. At times, I would lose power, or the power light would begin blinking, indicating low voltage. This was made worse by the fact that the mount power connector rotates with the RA axis.
I was slightly put out by this glitch, but found I had a Celestron power cable on hand that fit better and worked perfectly. In their defense, a quick email to Orion, brought a new and functioning DC power cable to Chaos Manor South in just a couple of days.
As above, after the holiday I got the Atlas outside for a checkout under the stars--at my friend Pat's observatory in Fairhope, Alabama during a brief respite from cloudy skies. Observations? The goto was good enough after a three star alignment, but not as good as on my CG5. On the other hand, the mount's stepper motors were far, far quieter than the servos used in the notoriously noisy CG5,
The next step was to see what EQMOD could do to improve the already impressive--mechanically, anyway--mount. The software was remarkably simple to get going, and, other than a wireless gamepad (a generic one works fine), it only required the purchase of two inexpensive additional items: a standard serial cable and an EQDIR interface module from Shoestring Astronomy.
The EQDIR ($35.00) is a small electronic widget that plugs into the laptop’s serial port (or a USB – serial converter cable); the serial cable plugs into EQDIR, and the other end of that cable is connected to the mount’s DB9 hand control connector (yep, DB9—none of that RJ nonsense for big dog Atlas). What EQDIR does is translate the serial-speak (RS-232) coming out of the laptop to the mount-speak (TTL levels) Atlas understands. Like every Shoestring product I’ve used, it worked like a champ. Indoors, anyway. As 2007 wound down, the weather just got worse and worse.
If the Possum Swamp skies wouldn’t cooperate, what would I do? Grab my trusty 1995 Ultima 8 OTA and the new Atlas and head for Chiefland, Florida, that’s what. In addition to checking-out the mount, I was hoping to get a few DSLR images for my forthcoming new SCT book, Choosing and Using a New CAT (Springer). That in mind, I packed a ton of imaging gear into the Camry and lit-out for the Chiefland Holiday Inn Express (for me, “roughing it” these days means staying in a motel) and the Chiefland Astronomy Village.
|The CAV field during one of the big spring star parties...|
In short order, I had the Atlas set up and its (jump start) battery connected, the C8 on the mount, and the laptop and EQMOD ready to roll. That was just the beginning, of course. There was also the EZ Up tent canopy, the camp table, the Toshiba laptop, three or four gear boxes, a sizable eyepiece case, batteries, extension cords, and the other numerous and sundry items I always bring along for a multi-night observing run. And there was even more stuff in the Camry's trunk, imaging stuff I didn't plan to mess with on the first night.
For the second evening, there'd also be the USB cable to the Canon 400D, the DSUSB interface box and connection to the camera, the Shoestring GPINT-PT module and the ST-4 style connection to the scope, the PhD Guiding program, and Nebulosity for camera control and image acquisition. Those things would wait for night two of my two night (should have been three, but the real world intervened) Chiefland adventure. I intended to devote night one to the mount and EQMOD and night two to picture taking.
Set up on the field, there was still an hour or two to go before sunset, so I made tracks for the Chiefland Walmart for a few items. One of which was bottled water. Even when it is cool, you have to keep yourself hydrated. You may not feel too thirsty, even if you begin to get dehydrated, but your get up and go, your stamina, will have evaporated and you'll be lucky to make it to midnight. Other than that, just the usual items: Jack Links Jerky and granola bars for midnight snacking, Monster energy drinks to refuel myself as the clock ticked toward morning, and a few bottles of Guinness for in the room relaxing after the run.
|Chiefland Holiday Inn Express...|
The details of the mount's PE characteristics, like the minutiae of all the gear and software mentioned above, is perhaps a subject best left for another installment. But even without talking arc seconds of error, the way a telescope mount acts when its told to go-to something and what happens when you give the scope a sharp rap upside the head—err “OTA”—go a long way toward telling you what the mount’s made of, so to speak. As would become evident after just a few hours of use, The Atlas EQ6 is one heavy mutha, in every way.
Despite my at home tests, I was a bit skittish about the EQMOD software, and that's why I'd decided to devote the first night to getting comfortable with it. It turned out I needn’t have worried. If anything, it’s even easier to get going than NexRemote, which ain’t no slouch in that department.
Start out with the Atlas in its normal Home Position (counterweight down, tube pointed north). An at least halfway decent polar alignment should have been done via the built-in (and excellent) polar scope. With the mount connected to the laptop via the serial cable and EQDIR, start-up the planetarium program of choice. That can be anything as long as it is ASCOM compatible. I chose the new beta of Cartes du Ciel, a solid and wonderful (and FREE) program I’ve used for years. Why didn’t I use my “usual,” TheSky 6? Tests showed a few problems using ASCOM and EQMOD with TheSky. Note that this is the only even marginally ASCOM compatible program I found to have difficulty with EQMOD, and I've been told that by tinkering with their computers some folks have been able to make the current version of TheSky work well with ASCOM.
|Cartes du Ciel|
Data entry complete, this is where things get interesting. It’s time to do a go-to alignment. Still in “setup” on EQMOD, click “n-star” alignment. What that means is that you are going to align on three or more stars (there is a one-star option that can work well if the mount is precisely polar aligned). A window will pop up with buttons that allow stars to be accepted and the alignment ended when all the stars have been centered. There are also directional buttons that can be used to move the scope to point at chosen alignment stars. If you’re like me, though, you’ll be using a wireless gamepad. One of the joys of EQMOD is that it will work with almost any joystick or game controller including the 10 buck wireless job I picked up at WallyWorld. Next step is to choose some alignment stars, and that’s where EQMOD takes a different path.
Rather than choosing stars from a list on a real or virtual hand controller, with EQMOD you click on stars shown on the planetarium program’s screen—any stars. Select Capella, click “slew to object,” and off the scope goes. When it stops, center the star and click the button on the gamepad that maps to “accept star” (there’s a utility in EQMOD’s set-up that allows you to assign gamepad button functions as desired).
When the Atlas stopped at the first alignment star, a look through the finder showed Capella was just a degree or two away. My next two stars, Castor and Rigel, were not just centered in the finder; they were in the C8 eyepiece at 100x. When these stars are centered and accepted, hit the gamepad’s “end alignment button.” How many alignment stars? I did three on the eastern side of the local meridian and quit. According to EQMOD's developers, best results are achieved if at least three on the east side and three on the west side of the meridian are used. Being lazy, I just left it at three.
|Atlas arrived at Chaos Manor South in November 2007...|
How do you actually send the mount to objects, though? Just click on an object, any object, on the planetarium program's screen and select “slew to" (or whatever command your software uses to send the scope on its way). Away she goes and said object is in the eyepiece. Simple, easy, sweet.
If all EQMOD did was allow the mount to do more accurate gotos than what the SynScan hand control allows, it would be impressive, but it does a heck of a lot more and features are being added all the time. There’re already add-on modules for things like PEC recording and refinement, and a Tour sub-program that’s intuitively easy to use. One of the next hings on the EQMOD feature agenda, I understand, is a polar alignment utility that should allow most astro-imagers to forego drift alignments. Got any ideas of your own? EQMOD's developers are more than open to suggestions and are found constantly inhabiting the Yahoogroup devoted to the driver.
How was the mount mechanically? I gave the C8, "Celeste," a slap on her rear (sorry girl) and she barely moved. It was almost as if Atlas were grinning—smirking—at me, “Rod, do you think I can’t handle a puny C8?!” Even with the tripod extended enough to bring the C8's eyepiece to a comfortable height for visual observing, vibrations caused by focusing died out in a second--if there were any vibrations at all.
Summing up…by the end of the first evening I was convinced the Atlas is a heck of a lot of mount for a heck of a few dollars. To really prove its worth, however, Atlas would have to show me he was up to the very difficult task of taking long exposure deep sky images. That was next evening, though.
After observing a goodly number of deep sky objects--off a list of 100 "best of the best" I am working on, perhaps as the basis of a new book project--the clock was creeping on toward three a.m. The night had been a long one due to the early sunset, and I was tired before I got going from the drive down and set up, so I was amazed to have made it so late. I reckon I was mesmerized by Atlas, purring like a big cat as he swung Celeste to target after target. Big Switch thrown, I was soon out to the car parked on the access road so as not to disturb my fellow observers, down the spooky lane of mossy old oaks, and back to Highway 19 and the motel.
|Down the spooky lane of mossy oaks and back to town...|
In the morning, I filled up on the Holiday Inn Express' biscuits and sausage gravy till I made myself sick, and returned to the room to try to figure out how to make the day pass. Despite my late, late (or early-early) evening, I was up not long after 8. I am used to rising at 4:30 to commute to work and just can't sleep in long. Winter sunsets come early, however, thank God, so the wait for darkness was not intolerably long. I filled the day by writing, reading the latest issue of Sky and Telescope, and surfing Cloudy Nights and Astromart on the laptop. A late lunch/dinner at the neighboring Taco Bell, and it was finally time to think about heading back to the CAV.
Out there, I shot the breeze with a fellow astrophotographer, who, with his SBIG and his T-Point and his AstroPhysics mount, was way out of my humble league. He approved of my Atlas/C8 setup though, and especially my Canon 400D Rebel, opining that if your main interest is pretty pictures, there's really no reason to use anything other than a DSLR these days.
Be that as it may, I got my new Canon (purchased at the same time as the Atlas) set for its first astro-imaging run. Ran up EQMOD, aligned on the same stars as the previous night, removed the diagonal and visual back, and configured the scope and camera for prime focus imaging. To that end, I mounted the camera on the C8 behind the f/6.3 reducer/corrector by means of a T-ring on the camera and a standard SCT prime focus adapter on the scope.
Gotta connect all those above mentioned cords and widgets, of course, including the USB and shutter cables to the camera. Shutter cable? Current DSLRs require you to have a remote release to do exposures longer than 30-seconds. The DSUSB box/cable I got from Shoestring Astronomy takes the place of that and allows my imaging software, Nebulosity, to expose for as long as desired. Neb lets me to operate the Canon much as if it were an astronomical CCD camera.
There was the guide scope, too. For me that is a 66mm William Optics SD refractor. Which guide camera? At the moment I am using my Meade (original color) DSI. Since it doesn't have a guide output to allow me to connect it to the Atlas' auto-guide port, I use another Shoestring adapter cable, which runs from the computer's parallel port to the auto-guide port and provides standard ST-4 guide signals. The guiding software I am using is, as I mentioned above, Craig Stark's PHD Guiding. "PHD" stands for "push here dummy" in this case, and that is really what is.
I loaded Nebulosity, and then went back to EQMOD to slew the scope to the evening's target, M42, natch. It's big, it's colorful, and it is bright, perfect as a first subject for a new camera and mount. When EQMOD beeped, indicating the mount was on target, I set the exposure in Neb to 2-seconds and pushed the "frame and focus" button. Shortly, an out of focus something appeared on the laptop screen. I focused carefully, making the stars as small as I could make them, and then switched over to "fine focus" mode. Click on a star on Nebulosity's display, and it is zoomed in. By observing this blown-up star and the graphs Nebulosity provides, it is easy to attain perfect focus. Viewing the camera's images on a big laptop screen is much easier than squinting through the tiny, dim viewfinder of a DSLR.
Now for the guider. I lit off PHD, began looping 2-second exposures, and focused till the stars looked good and small. I hit "Stop," clicked a likely looking star, and clicked the Guide button. PHD calibrated, moving the star in all four directions to gauge how the mount reacted. I was gratified the Atlas displayed little or no backlash in declination--my CG5 has a bunch. When it was done with the calibrating, PHD immediately and automatically started guiding. That's all there is to it, loop exposures, stop, guide. It really is "push here dummy."
Back to Nebulosity. I set up a series of 20 three-minute exposures, clicked the start button, and Neb began doing its thing. PHD was, as I could see when the first sub came up with nice, round stars, locked on. There was literally nothing for me to do while the exposure series was in progress. So, I wandered around, talking to/annoying my fellow observers, ducked into the Clubhouse to retrieve a Monster Energy Drink, and cooled my heels until, somewhat more than an hour later, the series was done.
|My first astrophoto with the Atlas/EQMOD...|
By the time my second M42 series finished, it was midnight. I was tempted to go on to a second target. B-u-t. There was the dreaded packing and drive in the morning. Even if I had wanted to go longer, Urania said "no" and closed down her sky soon after my last M42 sub-frame completed. As is often the case this time of year at the CAV, ground fog was creeping in. I managed to shoot the last couple of frames through the fog, but ten or fifteen minutes after the last one finished, another wave of fog rolled in, covering the scope, blocking the sky, and causing me to pull the Big Switch. That's just the way the cookie crumbles. By the time I got back to the motel, it was well after 1 a.m., so, given the drive home in the a.m., I was wise to quit when I did, fog or no fog.
At the Holiday Inn Express, I couldn't resist taking a quick peek at some of my subs. They looked darned good, even without processing. Most amazing thing? Nebulosity was wonderful. EQMOD was wonderful. The Atlas was wonderful. The Canon was wonderful. Most wonderful, however, was PHD Guiding. It just, yes, LOCKED ON. Still, I didn't realize just how good a job it had done for some time. Later, I discovered that, due to a peculiarity in my Atlas' particular motor control board, when you use the mount with EQMOD the RA speed needs to be adjusted slightly (in EQMOD) for correct tracking. I didn't know that and hadn't done that. PHD didn't care. It gave me round stars, anyway. Yeah, amazing.
I toasted Mr. Stark's amazing programs with a Guinness or two, watched a few minutes of the somewhat odd and very silly Ghost Hunters on the teevee, and fell into a deep sleep ruminating on how preposterously cool it was that the new Atlas and all the other new gear and software worked perfectly the first time out. Sometimes you get lucky, muchachos, sometimes you just get lucky.
Since I've linked this rather memorable (for me) article to a July 2017 post, I thought I might bring you up to date concerning Atlas and EQMOD.
If you read the post I've linked this one to, you know the Atlas is probably going to be sold after having been with me for nearly 10 years. It's just too heavy for me now given the back problems. While I wouldn't be averse to replacing it with a new EQ6 like the EQ6-R, which has a handle that makes it much easier to lift, I'm thinking I'd be wiser to go with a lighter mount with similar payload capacity. Maybe the iOptron CEM60. That said, the Atlas still works every bit as well as it did on that long ago Chiefland trip.
Yes, an iOptron or Losmandy might be in the cards, but I sure would hate to give up EQMOD. While I haven't used it a lot lately--due to me being happier using my lighter, non-EQMOD compatible Celestron AVX--I still love EQMOD. What's changed with it in nearly ten years? It's gone through many updates and is better than ever. It still works and looks much the same, though, and that is a good thing. The chief developer now is Chris Shillito, who's continued refining the driver, and has even produced some wonderful instructional videos on Youtube that can get anyone up and running with EQMOD in a hurry.
The Canon 400D? While I've gone on to "better" DSLRs in the intervening years, I still use my old 400 for much of my imaging. I like its light weight and larger, more sensitive pixels as compared to my newer and more expensive Canons. I did finally give in and buy an AC power supply for it, though.
My Shoestring shutter controller still works great. I did, however, replace the original EQDIR module with an integrated solution, a single cable that plugs into the computer's USB port on one end and the mount on the other. No separate USB - serial converter is required, and it is a neater solution with fewer worries about (mechanical) connection problems.
Choosing and Using a New CAT was published not long after I wrote this post and continues to sell well, though it's beginning to get a little long in the tooth.
Finally, there's Chiefland. It's been a couple of years since I've been there, and changes there and with me mean I'm not sure when or even if I will be back. I sure had a wonderful decade of frequent trips down Chiefland way, though. What fun I had, and what great memories I have--especially of this particular trip.
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Looking good, I guess I wasn't the only one who got an Atlas EQ-G for Christmas. Took the ole PowerStar 8 off the forks and as you say,it's like a rock now. The shoe string interface works just great. I only wish the skys would clear up here in Oregon, so I can use it. Thanks for the simple to follow alignment information.Post a Comment
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