Uncle Rod's Astro Blog

 

“Well, I made it and made it before July ran out. Just barely, but I did!”

“Hell, sounds like Unk’s been hittin’ the dang Yell again.”

Not at all, Skeeter. Well, maybe I have had a drop or two of the Rebel Yell, but I ain’t any more addled this morning than any other morning.  What did I make? My yearly portrait of the Great Globular in Hercules. It’s one of my little yearly rituals, like my Christmas Eve look at M42. 

I really wanted to get Herc done this month—before you know it, the constellation will be plunging into the west. Unfortunately, this July's weather has not been conducive to any sort of astronomy. Rain. Heat. Bugs and lots of ‘em. In other words, a typical summer in Possum Swamp, muchachos.

What I did was keep an eye on the Weather Channel and Astrospheric. That paid off last Sunday evening. The day had been mostly cloudy. Hell, at sundown, it looked like we were in for another round of thunderstorms. The forecasters stuck to their guns, though: “Mostly clear.” By dark, the clouds had rolled off, and I was left with a clear but hazy July sky. Hokay, time to get a telescope into the backyard.

Which telescope? Do you even have to ask? There was simply no way I’d deal with a conventional scope under these conditions, which included a temperature that would still be near 90 when astronomical twilight came in. If you guessed, “Miss Suzie the SeeStar S50 smartscope,” you’re right on the money. This was the perfect time to let the scope sit out in the steamy backyard and do her thing while I sat on the couch with the cats watching TV and drinking cold 807s.

That and only that would, however, be a repeat of exactly how I captured Herc last year, and normally wouldn’t be much of a subject for an entire blog entry. There would be something different this time, however. A very big something…

The SeeStar is a great little scope hampered by one big limitation: alt-azimuth tracking. That creates problems like field rotation, and depending on the object’s elevation can result in The Suze rejecting a large number of sub-exposures. As y’all know, I’m not after perfection. However, alt-azimuth tracking results in pictures that can be just a little ugly sometimes, uglier than I want even my simple cosmic snapshots to be.

Not long after the SeeStar was released, its fans began clamoring for an equatorial mode. Some creative souls even managed to run the scope in equatorial fashion using workarounds to fool the software into tracking in EQ (and even being able to do gotos in limited areas of the sky). ZWO, the SeeStar’s maker, watched and listened, and a few months back released an update for the SeeStar app and firmware that, yes, included EQ mode.

I was quick to download the new stuff, but a couple of things got in the way of me trying it. One being wrapping up the semester at the university, and the other being my involvement in putting on our big yearly amateur radio event, The Mobile Hamfest. I really wanted to give EQ mode a try, though, and M13 night seemed to me to be a good time to do it.

The hardest part? For your impatient old Uncle, it is indeed the waiting. It was nearly 9pm before I could begin the process of turning Suze into an equatorially mounted scope. When that time finally came, I began with step one, which is tilting the scope over so she points at the pole, roughly. Some SeeStar owners have invested in little equatorial wedges. ZWO sells one and so does SkyWatcher, and they are nice enough. As you know, though, your Old Uncle is loath to spend a dime if’n he doesn’t have to. I have a fairly heavy duty Manfrotto tripod. It’s never failed me for any photographic task in the 20+ years I’ve had it. Why couldn’t I just put Suze on the normal head and tilt that so as to point Missy at Polaris?

It turned out I could. As you can see in the picture, down here at 30 degrees north latitude, the little scope is really tilted over and hanging out in space. I was a little leery, but the Manfrotto seemed steady indeed and Suze didn’t plunge to the ground or anything. The only catch to keep in mind when you are setting up: be sure to mount the SeeStar so that the power button is pointed up when the telescope is initially pointed in the direction of Polaris. Done, I could proceed to the second (and last) step, polar alignment.

To get going, you connect to the Seestar with your phone, go to “Advanced Feature,” mash “Mount Mode,” and then touch “switch” to go from alt-AZ to EQ. Next, you’ll see a graphic of the scope and two numbers, the current latitude and the SeeStar’s current angle. Don’t mash anything on the screen, just adjust the tilt of the scope till the two numbers match. Which I did. While it would no doubt have been easier with a wedge, it wasn’t difficult with the Manfrotto’s pan-head, either.

When the tilt is good, touch, “Get Polar Align Deviation.” That will cause the scope to point near the celestial equator. When it stops, you will be presented with two more numbers, up/down and left/right, that indicate the direction and how far you need to move the telescope to polar align. When polar alignment is within one degree of the pole, you’ll bit a big, green checkmark on the screen. I strove to get both deviation numbers as small as I could, but I didn’t agonize over it. Even with “just” a camera tripod head, adjustment was not difficult. If all this sounds slightly confusing, the in-app help on polar alignment is well done and explains everything. 

And then? That was it. I could get inside out of the heat, change my clothes, settle down on the couch, and send Suzie to M13 using the built-in star atlas. I didn’t notice much difference from alt-az, with the SeeStar doing her usual calibrations and autofocus routine. I did note that when the first live image came in, M13 was dead center—but the S50 is usually good with her gotos. Now to set subframe exposure time. With EQ mode comes the ability to shoot sub-exposures up to 1-minute in length. First time out, though, I decided to stick with 10-seconds and see what was what.

Cool and comfortable again, I let the girl do her thing on Herc. What did I notice when I’d glance at the iPhone over the course of the evening? Suzie was not dropping many sub-frames. In fact, I’m not sure she rejected even one during the half-hour sequence of M13. This with Hercules at the zenith and crossing the Local Meridian—not a great place to shoot due to balance changes causing tracking problems.

When the girl had accumulated that half hour of subs, I did a quick AI denoise on the result, saved that and the un-denoised version and moved on to the next target, Hercules’ M92, natch. That done with purty much identical results, few/no dropped subs, we finished the evening with my old “The Friendly Stars” pals, the globular clusters M10 and M12. By then, it was past 11pm, way past your tired old Uncle’s usual bedtime.

What did I think of my results by the light of day? I was impressed. The stars are not quite perfect, but more than good enough for me, and I believe they would have been better if I hadn’t been shooting near the zenith the whole night.  I was very impressed by how much smoother the pictures looked, and, of course there was no field rotation “noise,” which will begin to be apparent at about the half-hour exposure mark in alt-azimuth mode. The smoothness of the result made those two little sprites, the galaxies NGC 6207 and IC 4617 easy to see.

So, honestly, I don’t see many reasons not to shoot in EQ mode with a SeeStar. Oh, I suppose if I’m in a real hurry, I’ll go alt-az—it took me about ten minutes to get the little gal polar aligned. I do expect that I’ll get quicker about that now that I am familiar with ZWO’s polar alignment procedure. So, to sum up: EQ MODE IS A WIN FOR SEESTAR USERS. BIGTIME.