Cruise Control Engaged

I’ll be honest. This post will probably take a few days to nail down. There are things I want to show pictures of but I haven’t taken those pictures yet. I might remove this paragraph when it all comes together.

Step one seems to be to decide if tonight is clear enough to warrant the attempt. I live in North Texas and we have pretty decent weather, most of the time. There are exceptions, of course. There is an eclipsing moon behind those clouds.

I have not scientifically tracked it, but I’d be willing to bet a small amount that we have more clear nights than obscured nights.

There are a couple of places where I might set up. Generally, I tend to set up at the end of the driveway, behind the cars.

This gives me a solid and repeatable surface and the evergreen trees block at least some of the direct light from the sodium streetlight on the property. Otherwise, things tend to look like this rather extreme example.

From this spot, targets southeast to northwest have the most open sky. There is a metal metal building to the northeast that limits me to about 10-15 degrees above the horizon, the house is southwest of this spot, limiting to about 25-30 degrees and a big tree is to the northwest. This has not actually been a problem thus far, but I’m sure I will need to try other spots in the future.

At this point, I have not yet traveled to a dark site.

I am also very familiar with exactly where Polaris is from this spot.

After setup, which is assembling and leveling the rig, pointing it generally at Polaris, positioning the power box and a camp chair (and sometimes a fan or heater), it’s time to polar align.

No, wait. I need to focus the telescope and camera first. The new way to polar align using the ASIAir needs the camera to view stars.

There are generally enough stars near Polaris to get focus there. And I don’t have ASIAir home the focus at the end of a session, so it’s usually pretty close already. The autofocus procedure is simple, though maybe a little time consuming. Start the process in the app and it begins by capturing an exposure and analyzing it for candidate stars to focus on. It then ramps the focus up and down over a range and plots the size of that star, optimizing for the smallest size.

The EAF position ranges basically in a 16 bit range, 0 to 65K. Once it’s happy with focus, now I can polar align.

The old way was to start by kind of painfully kneeling low enough to peer through the polar scope on the mount. Consulting Stellarium or some other app for the correct position of Polaris in the scope, I would scoot the tripod to get close then use the wedge screws to dial it in. I would start a timer and check it again in 10 minutes to make sure Polaris is stationary in the reticle.

The new way is not necessarily faster, but it is much easier and I get much better alignment. I start with the laser. It really surprised me in how helpful it is in getting really close to alignment, but indeed it does. Plus, it looks pretty cool.

In the interest of full disclosure, I generally do this laser bit before any of the rest of it, as soon as Polaris is visible. Then I focus, etc.

Then, using the ASIAir polar alignment tool, the controller will instruct you to point toward Polaris and press start. It will take a shot and plate solve it. Plate solving is a method used to determine exactly where the telescope is pointing in the sky by comparing the star field in the image to a database of star positions. It will then move the telescope 60 degrees, take another shot and plate solve that. Then it does some magic math and shows you where you are pointed vs where the North Celestial Pole is.

This isn’t my screen capture, but is a good example. Some people say to ignore the little graphic. I say use it and the directions on the right hand side of the screen. In this example, you need to point the telescope 1 degree, 20 arcminutes (just call them minutes and seconds) and 39 arcseconds to the right (east) and raise the elevation a scant 16 minutes and 41 seconds. A full circle is 360 degrees. A (arc)minute is 1/60th of a degree and 1 second is 1/60th of an minute or 1/3600th of a degree. We are talking very very small movements here. As the screen suggests, within 5 minutes is reasonable, but you will get the smiley face if you get within 3 minutes. Thus far, I have used only the Redcat 51 with all this. I understand that too wide of a field of view makes it difficult for the software to see your adjustments and too narrow of a field of view amplifies your adjustments, making it prone to oscillate either side of alignment. I got to 4 minutes the first time and barely under 5 the second.

ASIAir has an “all sky” polar alignment feature that does the same basic process, but you don’t have to begin pointed *directly* at Polaris. This is intended for when Polaris is obscured by something. I have not tried it yet, but I will soon, just to make sure I know what to expect.

Next, find your chosen target. ASIAir has several ways to do this. Probably the easiest is to use the onboard Star Atlas. It will sort by things that are viewable from where you are. You can scroll and choose something or search. Generally, using the official catalog names are the best way to search, “M31” vs “Andromeda”, for example. The data displayed shows the rise and set times for the object and the relative magnitude (brightness; or really, dimness. Higher numbers are dimmer). You can preview the framing of your image; it knows your telescope and camera parameter, so it can calculate the size and shape of your field of view. Then comes the reason I dropped too many dollars on equipment in August. GoTo.

The mount will slew in both axes to your chosen target, then plate solve and adjust to center the object. It is magic, compared to all the other ways.

Take a picture, long enough exposure to see the object. Once there you can preview again and from the preview, you can choose to rotate your camera to frame the object better and adjust the red ‘target’ reticle to where you want the telescope to move to and choose GoTo again. Repeat this cycle until the object is framed how you want it.

To note, the nebula image above is from the ASIAir’s library, not from the camera at this point. There must be a vast amount of data in that atlas.

Then it is time to start taking some real frames.

Maybe. One advantage of a cooled astronomy camera is that the dark frames and bias frames are going to be very consistent; their purpose is to capture the noise of the sensor at the temperature while shooting. Without a cooled camera, one should take darks and biases with every session, generally at the end. With a cooled camera, however, you can take darks and biases anytime the camera is cooled to the same temperature and reuse them as long as you keep it set to the same temperature. You probably should refresh them periodically, maybe seasonally, when the external conditions can have the most effect on the camera’s cooling capacity. I think I would take new ones if I traveled for a session.

Flats, however, you should capture for each session. Darks and biases are taken, as the name dark might imply, in darkness. Flats instead need a diffuse featureless light to allow the software to compensate for visible anomalies in the optical train, like dust, scratches, etc. There are a lot of flat illumination options, like iPad screens or LED tracing panels. The important thing is that it does not have any image data within it. It’s probably best to take them at the end of a session, but if you’re running it on autopilot and maybe you are comfortably asleep when the session ends, it makes sense to take them at the beginning. Your mileage may vary.

There are a couple of ways to start taking images. The Autorun feature is pretty usable. You can line up several segments of a session, but I had trouble getting it to pause between them. There is probably something I don’t know (as if!), so I tend to put one segment in at a time. I set up and get my flats. Then I set up and get my subexposures or lights.

Here, we are setting up for 10 exposures of 5 minutes each. The image names will be prefaced with “Light”. I don’t fully understand the Bins at the bottom, yet, but I think they are related the use of multiple filters for the same target, for example, LRGB color images with monochrome cameras.

The Meridian Flip option is something I have not done in the past with my guider, but then I may have just been lucky with target choices and the time of day. So, there is an imaginary meridian line directly above you and when your target crosses that line, you should flip the camera over. This is to prevent it from tracking beyond the mount’s physical limits until it hits something. Interestingly, it stops taking shots a few minutes before the flip. I think there may be a “dead zone” of sorts, real or imagined and it’s giving time for the target to traverse that zone before it flips. After the flip, it will plate solve and recenter before it begins taking shots again. Also, stacking software wont care that some of your subs are 180 degrees off from the others. It will correct for the rotation.

The longer a given subexposure is, the better the signal to noise ratio is for that sub. 200 subs at 60 seconds each is not as clean as 60 subs of 200 seconds each, even though they are both 200 minutes in total time. Also, fewer subs will stack faster.

The key to really long exposures is good tracking and the golden key to good tracking is autoguiding.

Tracking, like my SkyGuider Pro does, is an open-loop process. The motor and gears in the guider run at a predetermined speed so that the mount moves at the sidereal rate, the same rate the the stars appear to move due to the earth’s rotation. You can get pretty long exposures that way. It works and it is simple and reliable.

Autoguiding closes that loop, giving the motors feedback to fine tune the motor speed continuously. Some guiding solutions have a separate small telescope with a, typically, monochrome camera. My ASI585MC actually has a built in guide camera at the same focal plane as the main camera. This eliminates the need for a second scope, ensures that the physical alignment of the guide camera is not subject to change, like a loosely mounted guide scope might introduce. The drawback to this method is that the guide camera is subject to any filters that may be installed in the optical train. In my limited experience, it hasn’t caused guiding to fail.

The guiding performance is displayed in a running graph.

The traces show the measured error in the guide star position, how far it is off from where it ideally should be. You want both of them as small and smooth as possible. The graph auto-ranges and honestly, this chart shows a pretty wide error rate. It should be below 1 and the lower, the better. I do need to work on improving the guiding and I have some things to try. For one thing, there is a calibration routine to perform and I have learned that I am not doing it the right way. YouTube is a treasure trove of such tutorials.

In any case, I was able to get clean 240-second long subs of the Western Veil Nebula, NGC 6960. This is on of the first subs taken after the meridian flip, which is why it appears upsidedown compared to the framing images above.

This is also my second capture of the Veil. The first was made with 240 subs of 60 seconds each, with no filters. This image above is a single 240 second sub, with a dual narrow band filter in place. This single image is almost as good as the stacked and post processed 240 images. Narrow band filters are the ticket, and they also “accidentally” filter a lot of light pollution, even moonlight.

There is another awesome feature of ASIAir that really helps with capturing the same target over multiple nights and it’s almost deceptively clever. Simply locate the last image (ideally) from the previous session and click GoTo.

It will plate solve the image to locate it then slew the mount to the same position and centering! Now you just continue shooting. Well, as long as you haven’t rotated the camera since the last session. Even so, you can do it, you will just have to work at getting the same rotation, at least close enough for stacking registration to deal with it.

This is the stacked and processed image from my first Veil capture. It was 240 subs of 6 seconds. I had 30 each darks and flats. I took 30 flats using an ipad for illumination, however because it was a clumsy procedure, I had to discard a couple of them at processing time. Still, it’s a decent picture:

This is the second Veil capture, with 60 subs of 240 seconds and a dual narrow band filter in place. This one is cropped to eliminate some of that empty space at the top of the image, but the uncropped version is framed exactly like the original.

Notice how much more detail is shown, especially the wispy blue stuff.

The plan is to capture another night or two of long exposure subs. If the guiding and skies will support it, I plan to do 300 second exposures.

My goal is to produce my own image not unlike this one, from the Wikipedia article on the nebula. I think I just need to capture much more light to do so.

Big Jump in Capability

My astrophotography hobby has been an interesting stair-step ride to more and more capability and automation (and dollars). I have reached a plateau that should hold me for a while.

First, I took pictures of the Andromeda galaxy with my DSLR, a 70-300mm kit lens, and a fixed tripod.

There are certainly pictures done better with similar equipment, but this one is mine.

The first major upgrade was an iOptron Sky Guider Pro and ball head. For the next year or so, I worked with this setup and it worked pretty well. Looking back, it seems I was maybe a little obsessed with Andromeda. Here is one captured with that rig, stacked with Deep Sky Stacker and post processed with GIMP.

Another year or so and I painfully bit the bullet and got a real telescope, a William Optics Redcat 51. It was about $850. While it was really hard to get me to click go on that, I have been very happy I did. It is a great scope.

With it and the DSLR, still using DSS and GIMP, I got really decent captures of the Orion nebula and a couple of others.

I also used it to get the April 2024 total eclipse.

Orion and Pleiades were captured with the assistance of a laptop running BackyardEOS. This had it’s pros and cons. The biggest issue was the kinda kludgy way that I had to run it.

This is literally during the Pleiades capture shown above. I dragged out another camp chair to sit in facing the laptop. There was the USB between the camera and laptop and power for the camera and dew shied heater. This convinced me to pucker up again and get an ASIAir, though it would be summer before I pulled the trigger on it.

Life intervened. Lost my job of 21 years and my car engine blew up. I was unemployed for 5 months, then once reasonably sure they were keeping me, I put a new engine in the car. Ironically, I would only attempt a couple of captures with it and for reasons unrelated to the ASIAir, they were iffy captures. One was almost all subs with a foggy lens because I just forgot to turn on the dew shield heater. I forget the others.

But it had been long enough now to consider upgrading something and what made the most sense was to get a dedicated astronomy camera. I chose the ASI585MC Air. This unit has a cooled main camera, a built in ASI220 guide camera and an ASIAir controller. As much as I love this camera, it was quite a butt pucker to place that order. The camera, even with an open box discount, was $900.

A mere couple of weeks later, I elected to get an autofocuser appropriate for my Redcat 51, which is the first generation with helical focus. Now that it is in place, I think I prefer it to the rack focuser, as least as far a compact package goes.

With this rig, I revisited Andromeda, but between light polution and just electing for a less than ideal amount of exposure time, it wasn’t a good capture.

I had long disliked the adapter that connected the telescope to the declination arm of the Sky Guider Pro. It is a solid steel piece, nicely machined, but its basically a twist and set the locking screw kinda thing and it makes it very difficult to do final framing. I decided to build up a solution for that. Sadly, it was never tested.

Once again, the equipment bug bit me and I pulled the trigger on a Skywatch Sky Adventurer GTi, a mount with go-to capability, and a couple of dual narrow band filters.

So the rig as it sits now has auto focus, autoguiding, a mount that can get me to a target and a controller to run it all and automate capturing subs. That is a long way from that stationary DSLR pointing at Andromeda.

I made the mistake 🙂 of adding up the major items. I am not counting various cables, cable management, and certainly not counting my Bluetti power box. Even so, including the original DSLR that predated the hobby by five years, I have spent a total of just under $4800. That is the entire journey, though, and many of those things are not part of the current rig anymore. That was, itself, $3100. Sadly, $2300 of that was purchased over a 30 day period this year. Ouch.

The first astro specific item was the SkyGuider, in June 2022. If we divide it out to the last purchase, it’s only $3.13 per day. Plus, I do still have the DSLR and SkyGuider. I might set up both and do a comparison capture. Actually, that sounds like fun.

Next post, I will go into some details about the new workflow.

Radioactivity is in the air…

for you and me….

I always thought it might be cool to have a Geiger counter. On the other hand, I never wanted to NEED to have a Geiger counter, ya know? Happily, it’s still optional, but the options are pretty compelling.

I was born in the early 60’s and like almost everyone else on the planet, I was quite taken with Apollo. I recall my older brother putting one of his friends’ motorcycle helmet on me and setting up a closet with a chair and few reimagined toys so that I could be an astronaut in my capsule.

While his interests ran more towards organic chemistry, I picked up more of a technological gene and I tended to build stuff. And take stuff apart. My father was a jack of many trades and I learned a lot about building from him. He was also a lapidary, which broadened my view into material sciences. By the time I was in middle school, I had long outgrown what the Radio Shack 150 in 1 electronics experimenter kit could offer. It was an absolute favorite Christmas gift.

Fast forward a bit and my career has been almost 100% technical and almost all of that has been one form or another of communications.

Having experienced the entirety of the Cold War as an observer, I was fascinated by nuclear energy. It is actually extremely low tech. Just bring a certain amount of certain metals close enough together for their base characteristics to magically generate essentially STUPID amounts of power. On the other hand, understanding and controlling this low tech challenged some of the most brilliant and gifted minds that the world has seen, before or since. It sometimes found them wanting.

I didn’t know that I liked math at that time. I think I just didn’t like the math we were being taught. I think it seemed like a lot of busy work, with no real tangible benefit. I’d rather keep designing circuits LOL. It’s amazing that a lot of what I played with worked at all, considering that I was just easter egging components and seeing what happened. I understood at some level that engineering was pretty math-y, but not in a way that triggered any interest in math. I had D’s in math class, but I calculated how many holes were in the acoustic ceiling tiles in the library at school, using what I didn’t realize at the time were statistical methods.

And it turns out, a LOT of the math in nuclear science is statistics. Whoda thunk it?

My practical interest in radiation stayed well below ionization energies. I worked in broadcast television, two-way radio, became a ham radio operator tinkering with microwaves, and implemented wireless burglar alarm systems long LONG before anything nearly as advanced as LTE or WiFi. When my career moved more into telephones, that eventually because digitized and eventually Voice over IP came along, giving me a significant shift in data rates, but no technology that I hadn’t already be working on or at least adjacent to since age 19. I’m 60-something now.

Beyond the brief but real concerns for global thermonuclear war in the middle there, ionizing radiation thankfully played very little *directly* into my life. In the burglar and fire alarm career, ionization smoke detectors are a thing. They work by measuring the resistance of a column of air that is ionized by the constant alpha emissions from a TINY piece of Americium 241. When some products of combustion enter this column, they raise the resistance of this column of air, triggering the alarm.

Photo electric smoke detectors shine a beam of infrared out into space, There is an infrared detector positioned to look at the space this beam crosses. When particles of smoke waft into this beam, more infrared is reflected into this detector, triggering the alarm.

These two technologies detect different parts of combustion. The photo electric need the relatively large particles of smoke to be detected. The ionization detector can actually miss smoke because the particles are relatively inert, but various gaseous hydrocarbons will change the resistance of that column of ionized air.

I see an ionization smoke detector in my future, but not as a fire safety device.

I have caught quite a few videos with radioactive subjects. Some of the more compelling presenters are Scott Manley, Kyle Hill and Tyler Folse.

With no small inspiration from Chris Boden, I finally started looking seriously at a modern radiation detector, specifically one of the offerings of Radiacode.

I dithered a bit, several months in fact, while I wondered if the novelty of such a device was worth the investment. My interests finally won out and I purchased a Radiacode 103. The Radiacode devices are based on a scintillator, a crystal of some sort that emits a tiny flash of light when a suitable particle or ray hits it. One advantage of this type of detector is that the flash can be measured and calibrated measurement of this flash reveals the specific energy of the detected radiation. By classifying the variation of this energy, it can identify the emitted spectrum and thus identify a wide range of elements. The Radiacode 103 is less sensitive than the Radiacode 110. Even at order time, I dithered between the two, with the 103 winning out for being a little less $, leaving me a little discretion to get a couple of accessories with it,like this stunning yellow silicone protective sleeve.

It turns out that the 103’s lower sensitivity makes spectroscopy take longer, but it is less likely to be overwhelmed in the presence of a really strong radioactive source. Lets hope I don’t get to test that out.

While the display on the unit can display a low resolution spectrum, it is much easier to deal with using the Radiacode app on a phone.

Once I understood some of the basic operating principles, I captured a pretty long background radiation baseline spectrum, 21 hours. The unit uses very little battery power. At the end of 21 hours, it had 89% charge left in its battery. I charged it anyway.

Amongst my many almost skills is TIG welding. I have quite a few tungsten electrodes. Some electrodes, for reasons that I have not adequately explored, work better with small amounts of various rare earth metals in the alloy. One of these, Thorium 232, is mildly radioactive. All radioactive elements are, by definition, unstable. They will radiate whatever particle they are prone to emit and transmute into the next lighter element in their “chain”. From a nuclear physics and quantum mechanics point of view, the decay of Thorium 232 it is a very very slow process. Thorium has a stupidly long half life of 14 billion years, meaning that, unstable or not, the vast majority of thorium in any given sample of the metal, will remain thorium for, in human terms, beyond forever.

Half life is a curious term. It is a statistical rating of how long it will take for half of the atoms in any sample of an element to have emitted whatever their flavor of radioactivity is and transmuted into the next lighter element in their chain. The decay chain of any radioactive element has a lot to do with the structure of the element, how many protons and electrons the nucleus has, how many electrons are in each electron shell, etc. For the Thorium chain, and really any alpha particle emitter, it will decay into something with an atomic mass divisible by four, four being the number of subatomic particles in an alpha particle. Duh, kinda. Next in line from Thorium 232 is Radium 228. Statistically, it will remain Radium for 5.7 years, then beta decay (lose an electron) into Actinium 232 for 6.1 hours, then beta decay into Thorium 228 for 1.9 years.

At this point, it gets into a bit of an alpha rush. Thorium 228 alpha decays to Radium 224 for 3.6 days, to Radon 220 for 55 seconds, to Polonium 216 for 0.14 seconds, to Lead 212 for 10.6 hours. That will beta decay into Bismuth 212 for 61 minutes and we finally reach a fork in the road.

Bismuth 212 can either alpha decay into Thalium 208 for 1.1 minutes, then to Lead 208 for the rest of eternity, or Bismuth 212 can beta decay into Polonium 212 for 300 nanoseconds then alpha decay into stable Lead 208.

Glossing over a LOT of details, generally, the longer the half life, the less radioactive the element is. Thorium 232 is interesting in that it has the longest half life of any element heavier than Bismuth.

I digress.

As mentioned, Thorium 232 is mildly radioactive, an alpha emitter. Alpha particles are not very penetrating. The plastic case and the silicone sleeve on my 103 are way more than enough to completely block alpha particles from getting to the scintillator in the unit. However, some of Thorium 232’s decay chain are beta and gamma emitters, which we can detect. Also, all of these, including alpha particles, can induce xrays in other elements, give us an indirect identification of alpha emitters.

The people at Radiacode are better at the math than I am, so their software knows how to identify elements based on the electron volt energies detected.

Remember thoriated tungsten welding electrodes? This is a post about thoriated tungsten welding electrodes.

I have a small variety of tungsten electrodes for my TIG welder. According to my testing with the Radiacode 103, none of them are thoriated.

So, I ordered some from our favorite abusive uncle, Amazon. I ordered a 3 pack of 2% thoriated tungsten electrodes. It was my own screwup that I ordered 0.040″ diameter rods, which are far too small for my current setup, which needs 3/32″ (0.09375″) rods. As an aside, I am now curious about the use for 40 thousandths electrodes and I will look into that. However, upon their arrival, I found that the large clear plastic tube that the electrode (singular) was in had a hole in the bottom of it that allowed two of the three to escape. They were not in the shipping envelope, so they were lost before shipping. As I’m sure everyone is aware, I doubt the people working in an Amazon warehouse are paid enough or allowed time enough to care if the package something comes in is broken.

Since these were ordered primarily as something to use specifically to test the Radiacode with, I elected to take my lumps and not deal with returning them (it).

I did find that in the direct presence of this electrode, the Radiacode definitely detected higher than background radiation, but it was definitely not a lot. It took most of 6 hours to register enough peaks in particle energy to identify the Thorium 232 decay chain.

The purple line represents the specific energy level that I am looking at here, which corresponds to the characteristics of Actinium 228, but note all the red lines at various peaks. These are other “fingerprint” energies which ultimately reveal that the spectrum under test is in the Thorium 232 decay chain.

Gathering this spectrum took so long because a single 40 thousands wire sitting directly by the detector does not have a particularly high count of radiation detection events. Today, I wanted to recapture this spectrum, so I broke the otherwise unusable electrode into several pieces, five to be exact, to concentrate the signal on the detector. I was able to get a really good spectrum in about 90 minutes.

Same basic results, just a little faster because there was more material right by the detector.

Between these two spectrum captures, I had a chance to fly to Virginia for work. For my first trick, I left the Radiacode turned on and in my laptop bag for the TSA security check. Understandably, it was briefly exposed to a fairly high dose of Xrays.

The poor thing was beeping an alarm at me when I retrieved the bag after TSA.

To put them all together for the day’s travel, there is at least double the count rate while in flight. This flight was Dallas to Orlando then Orlando to Norfolk.

Note the gradual slope while climbing and descending. There are also noticeable dips that appear to be while I aboard, but we were on the ground. I am not sure what causes that.

For some reason, this historical data does not show the similar dose rate. I am certain that I dinked with some setting that broke that, some scaling factor I would guess. Shrug.

Stop The Presses!

Ok, it’s not *that* important…

I have bought a LOT of stuff online. Some, such as my wife, would say I have bought too much stuff online. That isn’t exactly what I want to talk about.

Most merchants will semi-randomly send an email asking for a review of some recently purchased item. Often, may usually, they are asking for a review of some extremely mundane thing that was *also* ordered with some fairly major purchase. One of my favorites is when I ordered a CyberPower UPS for $240-something dollars and in the same order, I had a small pack of washers, not even fancy washers. Plain ole’ mild steel washer with a zinc coating. Guess which item they wanted a review for?

I had a similar thing happen recently. I ordered my ZWO EAFN and accessories from Agena Astro. The EAFN was $180 and the (arguably unnecessary) ZWO focus hand controller was $30-something. The email wanted me to review the hand controller.

So I did. Admittedly, I had Claude.ai give me a framework to build on, but here is my review of the ZWO EAF Electronic Automatic Focuser Hand Controller:

★★★★★ 5/5 — This Focuser Changed My Life (And Possibly My DNA)

I want to start by saying I was a skeptic. I’ve stared into the void of deep space with my own two trembling hands turning a focus knob like some kind of caveman, and I thought, “That’s fine. That’s good enough.” I was wrong. I was so, so wrong.

The ZWO EAF Electronic Automatic Focuser Hand Controller didn’t just improve my astrophotography setup — it recalibrated my understanding of what it means to be a person. The first time I pressed that little directional button and watched my focuser rack in and out with silky, motorized precision, I wept. Not from joy. From the sheer, crushing realization of how much of my life I had wasted twisting things manually, like an animal.

The buttons themselves are a masterclass in tactile engineering. Each press feels like a gentle handshake from the future. The step-size adjustment dial doesn’t just change increments — it changes epochs. I no longer measure time in minutes. I measure it in focuser steps.

My marriage has improved. My cat now makes eye contact with me. NGC 7000 has never looked so sharp, and neither, frankly, has my soul.

Do I need this to focus my RedCat 51? No. Did I need fire? Also no, technically. But here we are, building civilizations.

Pros: Everything. Literally everything.
Cons: I now feel deep, personal contempt for anyone still focusing by hand. I look at them differently now. I can’t unsee it.

Five stars. Would sacrifice my other astro gear to a black hole to keep this one item.

Quick Update

As mentioned earlier, I ordered a Vixen clamp with a 1/4-20 threaded hole to interface between the rotating platform. It’s not red, but it still works 🙂

Nothing makes dust show quite like a bright camera flash.

I also got a glorified laser pointer to help with rough polar alignment. This is a Move Shoot Move product specifically for the iOptron Sky Guider Pro.

Argh. The dust. Obviously, there is some cleaning to be done and when I leave the rig assembled in the living room waiting for clear nights, it needs to be covered.

Anyway, as of this writing, I have not yet tried out either accessory.

Of course, I am already considering a mount upgrade. To be honest, I have thought about it for a while, ever since it became obvious that locating targets can be challenging. It makes no sense to upgrade at all if it’s not one that is go-to capable.

The preference would be for a ZWO AM3. It wouldn’t need any counterweights, which would keep the rig compact. It is elegant. It is red. 🙂 There are, however, 1500 other reasons to shop around. Nice as they are, the price would tough for me to justify.

The most economical go-to mount today seems to be the Sky-Watcher Star Adventurer GTi. The retail for about $580. A kit that includes a tripod would be about $680. This would enable other features of the ASIAir software, as well.

I could attempt to recoup some of this cost by selling my iOptron SkyGuider Pro and tripod, and my redundant ASIAir Plus. All tolled, I invested almost $1000 for these items and the accessories they would include. Perhaps I could get $400-500 for them. That is most of the way there.

Gate Power Update

A question posted on a Facebook group this morning inspired a reply post in which I told the CliffsNotes version of the gate story. That has inspired me to update here.

In short, the OP in the group was asking for advice on providing solar power for a security camera. The generalized advice give came in three basic forms.

  1. An off the shelf solar camera. Reolink, for example, makes several models. I have been considering this option to deploy cameras where I can better monitor the horses in the pastures. I did consider this for my gate camera, but I was also already into a mild sunk cost fallacy of wanting my own system to work. Plus, eventually I needed more than just a camera at the gate and my solar system now provides power for all of those devices.
  2. An off the shelf solar power pack. Honestly, looking for something like this had not even occurred to me when I was developing this gate camera power system. While I don’t think the reasonably priced units would have worked in the long run, for just the camera, it would be pretty elegant.
  3. There was quite a lot of advice on sizing and building a solar power system. The gist of the advice was that you need 3-4 times more solar and battery capacity than your load requires in order to keep a battery charged with only 8ish hours of sunlight a day and especially for marginal cloudy days.

I think my major contribution to the conversation would be my logged battery voltage, showing the tendency for the battery to trend lower each day when there is inadequate sunlight for a full charge.

The Shelly UNI battery voltage log on Home Assistant now has nearly 9 months of data to review. Here is the year to date chart:

This is also kind of a weather log. Dark regions reflect cloudy and/or rainy days where sunlight was low. For example, the significant dip in late January corresponds to a few days of light snow, sleet and stupid cold temperatures, a low of 11F. Similarly for the low dips in early March, late April and early May, all cloudy and stormy days. Almost no significantly cloudy days since May 21. Wunderground history is a very handy resource.

The trend revealed here is that, other than the dips from cloudy days, the nightly low voltage slowly climbs from January to May, where it remains pretty stable to today.

Aiming Too, Please

One of the things that has bothered me about the whole rig for a long time is aiming in declination. Currently, I am using a steel mounting block that came with the SkyGuider. It is pretty secure, but the thumbscrew locking method frequently results in it moving after carefully aiming it. Also, if the particular right ascension position has it leaning very much, then this mounting block can be difficult to secure because of the way the the mounting block thumbscrews want to seat in a groove, but the whole assembly is trying to wedge out of said groove.

This has been a bother since day one. So much so, that three and a half years ago, I ordered a Sky-Watcher Star Adventurer declination bracket. This is designed to fit, perhaps obviously, the SkyWatcher Star Adventurer. Importantly, it has a rotating platform for the rig to mount to.

While this picture is obviously intended to spotlight the rotating platform, it is technically upside down. 🙂

Sadly, I could not figure out a way to attach this whole assembly to my SkyGuider. I recently decided that the best way would be some kind of right angle bracket. I shopped for some suitable sort of commercial bracket, to no avail. I realized that I should just make one.

The four screws attach the bracket to the top of the iOptron dec bracket.

Then the rotator is attached to the top of the bracket.

Note the clutch ring. Loosen the clutch and your can freely rotate the rig. Tighten the clutch, then the knob on the side turns a wormscrew to fine adjust the position.

This assembly was completed just last night. Weather permitting, I hope to try it out tonight.

For the moment, I have it clamped into a 1/4-20 hole on the bottom of the dovetail rail. Happily, there is a hole very near the balance point, but I would still rather have it in a dovetail clamp.

Of course, I have a dovetail clamp of a sort. This one is made to attach to the bottom of the ASIAir Plus and connect it to a Vixen dovetail plate. It has crossed slots in it. The 1/4-20 stud on the turntable isn’t long enough to reach through the slots to a nut. I ordered one that has a suitable threaded hole, but I am prepared to modify this one if that doesn’t work out.

First… Light?

The camera arrived without drama.

Before the ink was dry on my last post, I decided to deploy an autofocus system for my rig.

I presumed that sticking with ZWO for components that chat amongst themselves is probably a good idea, so I ordered a ZWO EAFN, a manual focus controller, a temperature sensor, and a Buckeye Stargazer mounting bracket, all from Agena Astro.

Since the ASIAir built in to the camera has its own ambient temperature sensor, this one is probably redundant. It is intended to let the autofocus elect to exercise focus based on a somewhat configurable change in temperature. This sensor is designed to plug in to a headphony looking jack on the EAFN, the same jack that the manual focus dingus plugs into, and it presumably reports to the automation via the USB. It could arguably be more true to conditions by sampling air temperature somewhere besides inside the cooling airflow for the SmartCamera, but point is to detect a rise or fall in the temperature, not necessarily the exact temperature *number*.

In any case, the stuff arrived, as did the camera itself.

Mechanically, the installation went well. I had only one real hiccup, and that was based on my own assumptions of how things should be, as opposed to how they are. 🙂

The T2 adapter to connect the Redcat to the Canon camera has an adapter ring that is secured to it’s base with three little grub screws. This has been in place ever since I first received the Redcat 51 in July 2022. More to the point, it had been on there long enough for me to forget that it was not connected to it’s own screw ring adapter. I tried for far too long to unscrew that single piece of nicely machined aluminum.

In the end, there is a 48mm to 42mm adapter ring that steps down the tube size between the telescope and the new camera, connected to a 21mm extension and a 16.5mm extension.

The focuser was generally a very easy installation. The Buckeye Stargazer mount components are all quite obviously 3D printed, but are also quite sturdy. The ring that goes around the helical focus ring is printed in TPU or some sort of flexible filament, so it has a tight but compliant fit over the focus ring’s rubber grip. The only thing I didn’t care for is that the rubber on the focus ring tended to flow and bunch up in front of the TPU ring while I was pushing it into place. Installation was thus a little bit fussy, but in the end, it is on there quite solidly.

I had the rig outside setting up and getting ready for nightfall. While I had it out, I played with terrestrial images for a bit, mostly to get familiar with the camera and ASIAir. It works quite well.

Happily, it was a clear evening and polar alignment was successful, other than the procedure’s affect on my knees. 🙂

Unfortunately, focus turned out to be the problem. The autofocus procedure needs some contrast to work with, so you need to manually focus to at least where you can see stars. It took me a while to nail down that with the focus ring nailed to lock beyond infinity, I still had fuzzy round blobs.

I took the rig inside and starting measuring stuff, backfocus in particular. Backfocus is the required distance between the sensor and the final ocular lens. Most other telescopes have a corrective pack of lenses called a field flattener. This is to ensure a sharply focused image across the flat sensor in the camera. By some agreed standard, this distance is typically 55 millimeters. The Petzval optical train design produces a flat image as is, so is not particular sensitive to the specific backfocus distance, and that if you can achieve focus, all is good. That said, most forum posts said to basically don’t worry about it as long as you can focus. There was the occasional mention of a 59.X mm distance involved with the Redcat 51. With the extension tubes I had in place, mine added up to 55mm, which *should* work but obviously wasn’t.

I elected to order an extension tube set to stretch it out. The SVBONY set from Amazon was inexpensive and includes, 5, 10, 15 and 20 millimeter tubes.

i had also ordered a filter drawer so that I would not need to disassemble everything to install a 2 inch filter inside the telescope. They are purposefully designed at 21mm to replace a 21mm extension, which is exactly what I did.

I went conservative and added only the 5mm for the next night. Turns out, I could not get it even to the round blob stage. It simply didn’t occur to me the night before to try *shortening* the extensions. I removed the 5mm and 16.5mm tubes, replacing them with a 10mm tube and tried again.

Success!

Now to try out autofocus.

Now I started taking a few randomish shots looking for the Andromeda galaxy. Upon reflection, I probably should have tried for a nebula, but the sensor size on the 585MC camera gives the rig an effective crop factor of 3.4. Crop factor is ratio of the sensor size you are using compared to the “standard” sensor size that is basically identical to 35mm film. In DSLR cameras, this is the “full frame” sensor. Because a smaller sensor is exposed to a smaller portion of the image, it is effectively magnified, assuming the pixel sizes are appropriately small. The crop factor can to applied to the focal length of the lens to determine the effective focal length of the combination. My Canon Rebel T6 has an APS-C sensor. APS-C is “Advanced Photo System type C”, something I learned today days ago. Anyway, the formula to calculate crop factor takes the pixel size as well as the height and width of the pixel field into account. The APS-C sensor gives a crop factor of 1.6. In practical terms, my 250mm Redcat 51 will perform like a 400mm lens (250 x 1.6) on the Canon. Similarly, the smaller sensor in the ZWO, with its even smaller pixels, will perform like an 850mm lens (250 x 3.4). Thus my interest in capturing Andromeda, to compare it to my previous Andromeda captures.

The plate solve feature in ASIAir turns out to be handy, though not quite as handy as I wish. Using Stellarium, I found the Ra/Dec coordinates for Andromeda. Using the plate solver, I found where I was pointed. This helped me walk my way to Andromeda maybe a little quicker. In any case, I found it.

I am new at the ASIAir thing, so I may or may not have done this the best way. I configured Autorun to get 40 bias frames, 40 flat frames, 40 dark frames then 480 light frames. The bias frames were easy, just leave the cap on the lens and pause the Autorun when they were done. For the flats, I didn’t want to move the rig since I had found Andromeda, so I used a white cloth illuminated by my LED flashlight, again pausing Autorun when they were finished. Darks were super simple, cap on and just watch the progress for 20 minutes until those were done, then simply remove the cap and let the lights go. I set it for 480 x 30 second frames.

Too bad my polar alignment wasn’t that great. It appeared solid when I set it. I generally set in in the polar scope then check it 5 or 10 minutes later to ensure that Polaris is still in the proper place within the reticle. I suspect that I unknowingly bumped the tripod after that, maybe in capping and uncapping the lens.

It wasn’t off by a gob. Andromeda slid off the screen very slowly, about an hour the first time, as in by the time I had noticed. I went out, paused the Autorun, reaimed and started it again, understanding that the capture was going to be compromised. It was, however, midnight, and I didn’t want to start over completely. This was largely going to be a shakedown cruise anyway. Looking at the lights, it seems like it took it about 2-3 hours for Andromeda to ooze out of frame. While not ideal, I suspect most of them will still be able to stack, even with very slightly elongated stars. Shorter exposures, even a lot more of them, may have avoided the TicTac stars, but the target would still have crawled off the frame.

And in the interest of full disclosure, I still haven’t processed that session.

The next morning, I found the telescope pointing very high in the sky, but the power cord had snagged on the top of the SkyGuider. It might have been able slip off had the power switch not been raised. I mused about how funny it might have been had it actually powered itself off. Sadly, it did not.


My State of the Art

It has been a bit more than a year since I posted the October 2024 eclipse story. I have not been super active in astrophotography, but I keep informed via YouTube and Discord.

Last night was the first astro attempt for several months. Short version, skies were mostly clear except about where Polaris is, so polar alignment did not happen within the hour or so before I gave up on that.

Instead, I turned to the almost full moon. (Yes, even with a full moon, I was going to try for a nebula somewhere) I had recently looked up some tips on lunar photography with my Redcat 51 and wanted to give it a try. The short version of that story is that I was able to snap a couple dozen frames. The previews or thumbnails looked promising, but the actual images were really blown out 🙁

Discussing this with friends in a Google chat, it occurs to me that, while astrophotography can start pretty cheap, especially if you already have a DSLR, the vaguely defined rules of time-effort-money apply. You can generally save one, but not all three.

Much of this chronology was discussed in an earlier post, but this time, the theme is the costs.

In my case, I started, with no concept of hobby astrophotography, with a Canon EOS Rebel T6 that I bought from Meh in 2017. Meh frequently has weird deals. I think they basically buy closeouts and get what they can for them. Sometimes it’s some protein bar, sometimes is a backpack, sometimes some oddly specific smart home light bulb. Almost always something that probably didn’t sell somewhere else. I’m not sure why they had a truckload of not really that out of date Canon cameras, but it was a bundle that would be $550 retail that they were selling for $340-something. For me, it was really intended to replace my film photography hobby from decades earlier. I did some minor accessorizing, such as getting a 70-300mm lens, a 500mm reflector lens which is actually not a great lens, a tripod, etc. I would take a number of decent pictures with it, but it didn’t really light me up until 2021 when I discovered the decoder ring that was Nico Carver’s “Nebula Photos” YouTube channel. I am not sure how the algorithm linked me up with astrophotography, but it did. The thrust of the video was how to do this on almost no budget, assuming you already had a DSLR camera.

Using the Rebel and a tripod, I followed the advice in probably this video to capture a very basic but not terrible picture of the Andromeda galaxy. This was untracked, stacked with Deep Sky Stacker and tweaked with GIMP. It was fun, but untracked, with a not particularly awesome 300mm zoom lens meant short exposures. Still, I was hooked.

The first dedicated astro gadget was a tracker, the iOptron SkyGuider Pro. It was $488 in July 2021. Now I could do much longer exposures and generally had better luck. I think it took a couple of sessions to get a decent Andromeda.

I also seem to do my upgrades in the summer and maybe July specifically. July 2022 brought the really big upgrade to the William Optics Redcat 51 telescope, the older one with the helical focus ring. It was $844, which for me was quite the sphincter pucker. I would not have much to show for it until January 2023, when I got my most favorite capture thus far, the Orion Nebula.

January 2023 also got me very nice picture of the Pleiades cluster.

The heavier Redcat was slightly more sensitive to my plain Jane tripod. It was a nice enough tripod, just not as solid as was needed for astro work. I ordered the iOptron tripod to fit the SkyGuider Pro in November of 2022, for just over $100. It was backordered and didn’t ship until January 2023.

The rig was pretty stable for a while. This is is the basic rig used for the October 2024 total eclipse. The external monitor was very nice for the eclipse, keeping me from bending in unlikely directions to view the camera screen. I don’t often go to the trouble of setting it up.

I took a bit of poetic license in assembling this composite. There were some passing clouds between third and fourth contact, so I used the sequence from first contact to totality, then mirrored them for the bottom half of the pic. I have also just noticed that this specific version shows an artifact of my manipulation. I have a version that is clean. 🙂

As mentioned in a different post, I picked up a Canon EOS Rebel T5 camera body. It was just under $100 from Adorama. I have used it mostly as a “replacement” for the T6 for casual photography, but I have always thought I might send it off for a full spectrum mod.

From here, I spent a good deal of time and some money on storage, mostly in the form of knock-off Pelican cases, some from Harbor Freight, some from Amazon. I currently have a case that holds the Redcat and the stuff attached to it, a case for the SkyGuider Pro, a biggish rolling case for most of the accessories and the camera itself. The accessories have not specifically been inventoried or priced out, but it’s stuff like battery eliminators and chargers for the Canon cameras, intervalometers, filters, cables, cable management stuff. Probably a couple hundred bucks worth of stuff, but I haven’t gone to the trouble to add them up. I predict that I probably will someday.

The next upgrade was something that I had watched for a long time and nearly purchased several times, a ZWO ASIAir controller. I ended up with the ASIAir Plus with 256GB of storage. I already liked using laptop software to control the capture, even if I had only done it a few times. The idea of being able to set up the rig and retire indoors, away from winter’s chill or summers insects was very attractive.

Most of the astro specific gear I have purchased thus far was from High Point Scientific, or sometimes Amazon, but the ASIAir came from B&H Photo. The controller was $350, but the whole order came to about $500 because of accessories, like a dovetail clamp for the ASIAir and some high performance SD cards. As befits my habit, this was ordered in July 2025.

It would be February of 2026 before I actually tried to capture anything using it. My stepdaughter and her hubby came out, ostensibly to see the planetary alignment, but we wanted to try to get some nebula or another while they were here. There was a bit of a learning curve with the ASIAir, but the ultimate failure of the capture session was down to bad viewing conditions. Often, the world fails to meet my expectations.

Work has kept me busy enough to not have much astro time since then. However, it’s July again, so…

Although I haven’t specifically had any *problems* with tracking, I have still been low-key shopping for a guide camera to further improve tracking and maybe up my exposure times another notch. Longer exposures mean more light on the sensor and more light means improved signal to noise ratio. Some guiding options are actually not terribly pricey, at least compared to $500 for this or $800 for that. It should be obvious that plan won’t work for me.

I weighed what I was willing to spend on a payment plan vs what was available. In the long run, I have decided to shrink the rig a little more by going with a smart camera, the ZWO ASI585MC-Air. I found an open box deal, so it came to, you guessed it, about $800, including an accessory or two. The ASI2600MC-Air, with its huge 21MP sensor, would have been my preference, but I wasn’t ready to pay nearly double for it.

This little monster has an 8MP cooled color camera and a 2.1MP guide camera that both sit in the same focal plane, eliminating the need for a separate guide scope and camera and the attendant cabling. Furthermore, it has an ASIAir controller built in, eliminating the ASIAir controller, the Canon camera and their power and control cabling. All in all, it should be a clean and compact deployment.

On paper, the 8.1MP ‘585 sensor is arguably less impressive than the 12MP sensor in the Canon, but the ZWO camera has two feathers in its cap. First, the WxH resolution is smaller, but the pixel size is significantly smaller, meaning a sharper image in that resolution. A Canon image cropped to the same width and height would still not be as sharp. Also, it doesn’t have the kind of infrared filtering that a DSLR has, making it better suited to the red and near infrared from emission nebulae.

On that subject, after I placed that order, I remembered that I wanted to get a dual narrow band filter with it. Our property used to show as Bortle 4 on the common light pollution maps, but in the last year or two, that has gone up to Bortle 5. That, and we have sodium and mercury lights in the neighborhood, especially including a sodium light on our property. These and my interest in emission nebulae have informed a desire to try out a dual narrow band filter. I ended up ordering an SVBony 7nm filter from Amazon. So there went my open box savings 🙂

The filter will probably arrive Wednesday, but the camera will be Saturday.

As for any future upgrades (and lets not pretend I won’t) I think it will either be a mount upgrade, which would require some kind of a go-to capable mount or, perhaps cheaper and more likely to come first, an electronic focuser. Focusing the Redcat, with the helical focuser, can be tedious. Automating that should help minimize setup time. I don’t really see a need to change telescopes to something with a rack and pinion focuser. Although… if I were to do that, it would also have to be an upgrade otherwise. Just getting the newer Redcat 51 wouldn’t make sense, but a telescope with a bigger objective *and* rack focus…

Stay tuned.

Too Many Variables

I am not prepared to panic, not yet anyway.

I have left the gate camera battery alone, other than monitoring it, for 10 days. Love the Shelly. More on that someday. Anyway, 11 days, technically. Today isn’t over, but 10 nights for sure.

You may need to click on that image to see the detail, but there is a pretty much linear decline in the “peak” nightly discharge. Overnight December 9-10, it discharged to 12.65 volts before a sunny day recharged it to 13.5 volts. Every night, it would discharge a little lower, then a sunny day would bring it back to 13.5 volts. December 13 was cloudy for much of the day, so we didn’t get a 13.5 volt peak, but the 14th and 15th were sunny enough. The 17th was dreary and today, the 18th has been sunny thus far.

However, each night, the battery discharges a little lower. 12.65 volts the first night, then 12.53, then 12.46. Each night lower until last night, 12.03 volts.

Here’s the rub. I don’t know if this is just a normal decline after the sorta mega charge from the AC powered smart charger and it’s just slowly settling back after that, or if it’s a symptom of a problem and I just happen to have a big enough battery to help make it take a long time to show up.

I do have an apples to pears example to compare with. I put the Triplett logger on the gate opener battery for week or so.

First, I love the sharp little peaks that (probably) show gate usage. If I get ambitious before this gets posted, you’ll never see this sentence, and will instead see my evidence that the little jabs in the opener chart correspond with gate operations. Or maybe because I just like this paragraph I’ll leave it anyway. You’re not the boss of me!

See, I told ya.

Dec 16 gate activity:

I am not sure what causes the positive spikes. There is nothing obvious in the gate camera at those times.

The two battery deployments are exactly the same thing except that the gate opener has an unknown but likely minimal charge control built in instead of a purpose designed solar charger controller, it has a small lawn tractor battery instead of a large deep cycle battery, it’s only a 10 watt solar panel instead of a 100 watt panel and the load is almost nothing most of the time instead of a camera, a WiFi AP and a Shelly UNI running 24/7. Both batteries are black plastic, made by the lowest bidder, so there’s that…

Since the data from both logging sources are available in CSV format, I thought I would try to match up the charts in a spreadsheet, but there are significant enough differences between the data sets, due mostly to the delta method employed by the Shelly UNI, that it is not trivial to match them up. The Triplett has even time between samples, the Shelly samples only when a significant enough change occurs. I am certain I *can* match up the data, but I’m not sure it’s worth the effort.

Even so, one can kinda look at the data and, even if I can’t easily share a spiffy visualization, I can report that the opener battery bottoms out at 12.67 volts consistently, give or take a couple of 100ths, each night in the logged data, unlike the big battery with the big panel, that seems to progressively lose ground every night.

Then again, maybe 10 nights isn’t enough to know the bottom of the pattern yet.

And who knows what spring and summer, with the sun higher in the sky will bring.

Too many variables.

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