discardedastro

So if I've got my ephems correctly plotted we should be in for quite a lot of still-relatively-bright viewing in the evening in the coming weeks. And if I stick my head out the door at 3AM tomorrow, might catch it - but it's in an awful place for my telescope where it is. Should be fine for the evening sessions though!

For Linux, for my money, PixInsight is the only real tool out there which can do end-to-end processing. Pricey, but worth its weight in gold, and the Linux support is outstanding (it's their primary platform). GIMP is a good tool for basic post work like adding signatures, and as mentioned above Siril and APP can run on Linux but I've not had good experiences with APP.

I do think there is room for improvement on pre-stack rejection algorithms. Definitely an area I'd like to spend time on. I've been thinking about trying to generate some synthetic data, train a ML model on how to spot trails, and then just mask all the trails and a buffer region as zero pixels so standard low rejection stacking can ignore the affected paths when stacking. Feels like it'd be a kinda fun project. Of course, it's fine for us lot mucking about doing cosmetic fixes for pretty photos. Less good if you're trying to get actual data for scientific purposes.

Linux is a bit of a complex beast, but worth learning in my view (I'm a recovering sysadmin so I've been fettling Linux boxes for over a decade now, but I've honestly never stopped using it - it's everywhere now and the Pi ecosystem is just one big example). The nice thing is that much like astronomy you don't need to know it all at once - you can very much learn as you go once you have the basics down. The "Unix philosophy" is about making lots of small things that do one thing (and preferably only one thing) well, and making it easy to put them together to do more complicated things, which lends itself well to lots of engineering disciplines in terms of the thinking, I think. My weatherproof box (just a big junction box) and cable glands have arrived, waiting on the dome now to have a crack at this myself - think I will use my 120MC for testing as I've got that to hand while the AP rig is dismantled for summer, but will pick up a Pi HQ camera board next month, and maybe a 3D printer to make an adjustable mount within the box to hold it at the right point within the dome.

sudo is "substituting for this user user, do..." and defaults to the root user. sudo -s says "make a shell as this user" - a shell being the thing you're typing into. root is the superuser account and best left alone if you can avoid it - you should never have to install or run anything as root (and this particularly goes for web applications). You want to run applications as a user - pi is the usual one. Your web server will also run with an "unpriviledged" account. The point being that if anything goes wrong or someone tries to make anything go wrong (i.e. attacks) then a user without full access can't do too much. Whereas if you're root, you can do anything. System configuration such as configuring systemd is often something that requires root access, so you use sudo to temporarily elevate your session for a given command. This avoids logging in as root etc.

You can do this, but it's a lot of faff and won't guarantee the focus algorithm will succeed - the Ekos algorithms all assume a reasonably high degree of repeatability (i.e. go to 1000, go to 2000, go to 1000 and you end up at the same place plus or minus a few dozen microns). Pulse drive motors will not generally achieve this because of backlash, and Ekos has no focus motor backlash compensation (outside of the linear algorithm, but that requires good repeatability to start with before it takes up the backlash). I'd definitely just go for a focusmotor. Swapped to the Sesto Senso last year and it's night and day from a pulse motor.

The CEMs are interesting mounts, have been tempted in the sense of considering a CEM120 as an upgrade should I ever need to go beyond what I can do with the EQ6R but the 6R's a formidable mount for the money! Not sure we'll see a lot of "post-lockdown" sell-offs, but it's possible I suppose.

The Nevada PSUs are well-regarded, e.g. https://www.firstlightoptics.com/batteries-powerpacks/nevada-psw-30-25-30a-switch-mode-power-supply.html would fit the bill in theory. 25A sounds like a lot, though - https://www.firstlightoptics.com/batteries-powerpacks/nevada-ps-08-6a-8a-regulated-linear-power-supply.html is likely to be enough if you're just using an NEQ6 and a camera or two, focuser etc.

Yeah, so - thread link is: The PSU in that case is indeed a fairly no-name brand. There was actual damage to the cable which caused a short circuit which damaged the PSU. The root cause was the socket/cable, the PSU couldn't cope. In this case, if the owner had checked the PSU with a voltmeter the fault would have been immediately apparent. In that case, a short-circuit would have had similar outcomes even with a protection board in. A fuse/breaker might've caught the fault, of course, and protected the gear, but the fault may not have generated enough current to trip it. A buck converter would likely have suffered a similar fate to the PSU and caused the same outcome. Use a reputable brand, make sure your cables/connections are good, and all will be well.

"Too low amps" leads to undervoltages which can absolutely damage electronics, yes, and will in any case cause problems with your mount - your motor drive boards will not have the expected power/speed and without encoders the mount is unable to notice and correct for this. Connectors need to be rated and specified for being unplugged and plugged in under load, and typical DC barrel jacks will be fine on that front typically but it is good practice not to do that, yes. Damaged power supplies are a rare occurrence, usually caused by environmental effects. While it is sensible to protect against damage to power supplies, good power supplies already do this - protection circuits on the output will stop the PSU driving high/low voltages. Placing that protection external to the PSU is fine, but you now need to ensure that your protection circuits aren't going to fail. I've seen plenty of cheap buck-boost boards fail to the high end of the input voltage range, for instance. DC-DC supplies in general also tend to undervolt much more drastically if they go near their current limits and in some cases will just outright fail and cut the output. The quality of power you supply is limited by the cheapest component in the chain - if your "protection" board fails then it can cause more damage than your PSU failing. This is one of those cases where less is more. Some devices are safer to include - for instance, you could put a small fuse or circuit breaker in-line with your supply cable. This can only fail closed (though you need to think about what happens when one half of your supply is still connected - depending on your grounding conditions, this again can be worse than doing nothing at all). You might see 19V at startup briefly, but that's fine - it's not going to "fry" a board. Try that again under load, incidentally, rather than with no load on the output - I guarantee you'll see a much more muted spike, if any at all. Transients are "normal". The best thing you can do to protect your equipment is to use a good-quality power supply rated well above your target load and to ensure your connections are made and secure before you apply power. I use a standard 12V cigarette lighter cable for my mount, and a DC jack feeds the input to some spring-loaded terminal blocks that I use to provide power to everything else on my telescope (about 6 different consumers overall) with a pair of blocks secured near the focuser to keep the cable runs tidier. The PSU is the basic Nevada PSU from FLO which can do 6A continuously, 8A peak. I've never seen any power issues of any kind in several years of use of this set-up. I really wouldn't worry about a good quality PSU rated well above the normal load failing. Failures are very rare. You do hear the occasional story from people who insist their PSU has enough capacity, but then it turns out they're drawing 4-5A continous out of a PSU rated for 3A continuous/5A peak, and other such silliness. https://www.firstlightoptics.com/power-accessories/nevada-ps-08-6a-8a-regulated-linear-power-supply.html The other thing to note about PSUs like the Nevada is they are linear - this is opposed to switched-mode which is the form you'll find inside most "compact" PSUs. Switched mode power supplies have a much more complex internal topology and can fail in more interesting ways- the market is also fairly well flooded with them. Linear supplies are less efficient but much, much simpler. The Nevada one is also regulated - this means the output voltage is controlled and fixed at 13.8V. Obviously if you exceed the current limit this "guarantee" goes away, but only in a negative direction (i.e. you can end up with undervoltage conditions). They are therefore very safe, as the last "item" in the output chain is a regulator. Obviously if that fails you're in trouble - but this is the case for literally anything, including the regulator in the mount itself producing the 5V for the control electronics, and any regulators/components in your 1 EUR "protection" device. This is a classic case of fault engineering where adding protective equipment makes the likelihood of a failure worse and doesn't actually reduce the impact of a failure except in some (limited - if your input goes to 230V, is your protection part rated for that, or is it going to fail and let it through?) conditions. My personal advice would be not to touch those cheap boards with a barge pole and make sure you use a good-quality PSU instead.

Not so - the drive electronics and comms electronics are fairly well separated, and even if the mount is struggling with current for drive, there'll be enough juice in the tank to keep the lower-voltage control electronics happy. The motor electronics all run around 12V, but the internal comms and control buses all will be at 5V or 3.3V fed from a regulator which will produce those voltages even with serious under-volting. For a steam train analogy, your PC's just talking to the driver, who can still blow their whistle and ask for more coal in the boiler. The fact that the train's run out of coal is not necessarily obvious to the driver. The control electronics can ask the motors to run at speed X for time Y, but if there's only enough drive current capacity to let the motors run at 0.8 of X, then Y is now wrong and your pointing will be incorrect. Power supplies are always underlooked as key, key components in any observatory or telescope rig. Being able to supply enough power reliably at all times for all components in concert is kind of essential. I would always aim for a PSU which is designed for 50-100% more power than you estimate you will need. On an EQ6-R Pro with 50% loading (~12kg) I can quite easily pull over 4-5A at times; I would not be surprised to see an NEQ6 pulling over 5A with what you've got on it, at which point your 5A rated supply is going to be really struggling if it's working properly. If it's got any degradation at all then you'll be well under requirements. Edit: and no, USB cable testing is the preserve of dedicated test hardware (and actually quite hard, especially for USB 3 cables - you're talking tens of thousands for a cable certifier that'll tell you anything useful). Buy another cable if you suspect a cable is faulty, and buy from a reputable supplier/vendor - it's much cheaper!

If you apply mains voltage across the input terminals of your mount then it is going to have a bad time. What conditions are you trying to protect against where you would see voltages beyond those typically provided by a 12V supply? If you are expecting to have wild, varying input voltages - that is what power supplies are for, they produce stable output voltages. Undervolting is the only thing you might be concerned about, but only if your supply is drastically under-rated for the demand you are putting on it. If you are supplying your mount off of something weirder than a 12V power supply that may produce voltages much higher than 12V, then you will need external input conditioning electronics - a power supply - to produce a clean DC12V output. In all other conditions, over-voltage protection is not required because it won't happen. The input voltage regulators will tolerate a bit of variance to accommodate the usual range of voltages that 12V systems actually run at.

There's nothing internal on the board, IIRC - voltage regulator but that's all. The connector's keyed so polarity being correct is the responsibility of the cable. With respect to overvoltage/overcurrent protection there's none needed. If you overload the mount weight-wise it's going to have issues regardless of what you do extrinsically. If you're worried about having enough capacity in your supply to provide sufficient current (and thus keep the voltage steady etc) then you want capacitors, not a boost-buck converter, but I don't know of anyone who has done that. Capacitors bring their own issues. I'd stick to a good-quality power supply.

I've not actually tried this but I have got a Z6 and an Ekos box set up so can give this a try if you want a check. But Ekos/KStars is an excellent ecosystem to dive into. The Esprit 100 should be a great scope with any of the cameras - I'd echo the comments that guiding is a good thing to add later on. I'd plan on a piggyback scope rather than OAG for a frac, which will work fine with Ekos/KStars. I use KStars on a Windows PC and a Raspberry Pi 4 running INDI on my telescope, with control and imaging over a (wired) network connection between the two. I think this should also work on OSX. I find it very straightforward as a setup and reliable/robust. PHD2, which is the gold standard for guiding, will work on OSX with such a setup, I believe.

Personally I use a Nevada 12V supply - I take the 6A cigarette socket for the mount, and use the screw terminals to secure some cable to power the rest of my setup (camera, PC, etc). Getting some silicone wire and some spring terminal blocks can help a lot to quickly make up power distribution runs very cheaply - I just take 12V into a pair of blocks (one -, one +) and then "fan out" from there to all the consumers, with a further pair of blocks at the focuser to feed everything there with only one cable run up the telescope. Either hack the ends off the existing cables or buy the required 2.1mm DC jacks or whatever it is your equipment takes for input power. 12V to 5V DC step-down converters are easy enough to take into such a setup, and it's quick and easy to reconfigure.

I've got a few Pi2/3s lying around and decided to buy a box and a couple of domes to try off eBay plus some compression glands. I reckon Ethernet in plus 12V on two glands should work fine. Need to rustle up a 12V PSU, of course. I'd avoid putting airflow holes in without filter material - you don't want ants etc crawling in. But I think a small fan plus some filtered positions for vents would be good (smaller outlet path than fan area, so as to achieve positive pressure). My initial attempt will be with my ASI120MC since I have that spare with the rig out of imaging mode. I'm not sure how I'll secure it in the right position just yet, my 3D printer has been out of commission for a while (very old Reprappro delta). Watching the thread with interest, in any case! Looking forward to playing with software on all-sky data - I'm hoping to build some ML classifiers for clouds etc. I've also been thinking about doing a seeing monitor, but I'd like to do an all-sky camera first. The results from the HQ camera board look promising!

Had some more time to work on things (I've had quite a bit of time, but Critical Role ( https://critrole.com ) has taken up much of that) and had gotten the surface ground nicely with 180 grit but had to go at it a bit more tool-on-top to get the ROC back to where it should be. All sorted now. I've had a first go at cleaning up the tool but I think I need to go at it with a brass wire bush to get the grit out as just melting the beeswax wasn't convincingly removing the grit. In any case, some progress. Need to get the cleaning setup reasonably slick if I'm going to be doing this often (as I hopefully will be as I progress through the grits).

I've found the Hotech lasers to be pretty good. I use the Barlow projection trick to confirm after a rough alignment with the unbarlowed laser. You should be able to see all three, yes. I found Astro Baby's guide great for this: http://www.astro-baby.com/astrobaby/help/collimation-guide-newtonian-reflector/ Vic Menard's book is another great guide if you want to really dive deep: https://www.firstlightoptics.com/books/new-perspectives-on-newtonian-collimation-vic-menard.html

I'd probably send it back to the shop and take your money elsewhere - seems a bit iffy. Swapping the primary isn't hard but shipping it back without damage is the trick - in the tube it's pretty well protected, out (even in the cell) it'll need careful packaging.

Yeah, the frosting is just a byproduct of polishing to flatten the back of the moulded blank and thus get it sitting flat in the mirror cell. I'd be a little concerned about a primary that hadn't been flattened, myself.

Definitely need an RCD whatever you do outside. I've not gotten a waterproof enclosure for anything yet - the mount and scope live outside, though, and this is definitely on my "want to do" list to make "walk up and observe" quicker and easier. Just make sure you run whatever 230V cable you run outside in a bright colour, ideally with protection like some flexible conduit, and away from where power tools might come into contact with it.

I'd definitely go for the Nevada. Not only does it have two outputs and terminals - which makes securely attaching bare ends/crimp terminals easy if you want to attach a lot of accessories alongside the mount - it has a handy ammeter on the front. Not the most accurate but it's a great way to see quickly how much power your mount is pulling, which can be helpful. They have a chunkier unit if you need more than 5A.

19kg OTA is fine on its own (though at the upper end of things). Pay careful attention to balance on all axes and consider the weight of your imaging kit - you'll easily add a few kilos for a camera, filter wheel, etc.

If you're stacking with PI then definitely stick to using XISF as a file format. And yes, fast storage is the best improvement you can make to most PCs to improve performance of PI - I have a 2TB Samsung 970 EVO Plus NVMe SSD for my active datasets and I can completely saturate even that (though there is a Ryzen 3950X to match - with half the cores, that disk is probably not going to bottleneck). But if you just hang onto your raw frames and your pre-stack intermediate data you'll be dealing with dozens of gigabytes per night of imaging quite readily, so a small fast-as-you-can-get SSD paired with a larger storage volume for older data is the way to go. I use a big 'ol pile of disks in the garage for storage of all my raw data.

I'd stick to saving files in XISF (PixInsight's default format). This format supports (lossless) compression which will help a bit. But stacked files will be large, especially if using 64-bit outputs - this is normal. I regularly rack up ~100GB processing folders, keeping all my intermediate data (a single frame is 80 megs or so, stacked image is around 120MB). Stacked RGB image is about 280MB. AP with modern sensors generates a ton of data! Having said that, looks like you're stacking externally with something else and then bringing FITS in - may be worth learning PI's stacking tools, they're really top-notch and straightforward once you get the hang of it (BatchPreProcessor will do a very good job of making getting to images ready to stack for you). That'd probably also fix your other issue.