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discardedastro

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Everything posted by discardedastro

  1. Good stuff, you can see what you're doing now! This does just take time+practice, don't worry. You basically can't break a scope doing collimation - just make sure not to touch the secondary mirror surface and you'll be fine. It doesn't look that far out of plumb - you probably want to move the secondary "up" and then might need to move it closer to the front of the tube (done by slackening all three adjustment screws off a bit, then tightening the centre screw - gentle forces on all of this). That'll get the secondary centred in the cheshire. Then take out the white card and have a look at your primary to get that well aligned. The various online guides with photos will help here, http://www.astro-baby.com/astrobaby/help/collimation-guide-newtonian-reflector/ is for your type (and nearly the exact same model) of scope.
  2. Got 3 Ha subs, with some small streaking - that needs investigating later. Also need to grab some 900s dark frames. Just finishing off some top-up blue to fill the gap left from my cock-up post-meridian flip and then it's teardown and off to sleep. It is great to have these nightly threads! Haven't gotten everything to the point where I'm happy sleeping on it, but a nap is mighty tempting. I've been crunching through season 4 of Battlebots instead.
  3. Velcro. Velcro everywhere. I've got some sticky-backed velcro pads on the OTA to act as anchors and pads for bits of kit like the Pi, USB hub, and dew controller, and then rings of velcro atop the anchor pads. Then layer velcro atop to secure individual bundles of cables - cheap, and easy to rework when you inevitably change things! That and keeping most of the cables on the OTA - there's only 3 leads from the OTA (mount control, DC, and Ethernet).
  4. I can heartily recommend the Lacerta DeltaT controller, it's kept my guidescope dew-free so far. Spoke too soon on the meridian flip - platesolved alignment somehow didn't end up landing back on target and I failed to spot the absence of my target in the subs 'till I pulled Blue across to blink in PixInsight. Argh. So now adding a few more blue subs after the Ha, which just aborted 5 minutes in due to a guide fail.... I've got enough data now to make an image, at least!
  5. Know that feeling. I think I'm going to get at least a few Ha frames in before I tear down, probably 45 mins. I've at least reduced tear down to unplugging an extension lead, carrying in a 12V supply, and popping the lens covers and scope cover on - but still need to be there to do it! That's a lovely looking setup though. All I have is a photo from the setup today.
  6. Definitely still has some quirks - I think if it were a bit more transparent/tweakable in the capture module it'd solve a lot of my woes. I've also had the odd crash, though it's been stable lately. SGP is definitely easier/more powerful in some areas - I really, really want Ekos to gain focuser temperature compensation support. Just performed a meridian flip 100% automatically, reset guiding, re-platesolved and aligned... not too shabby!
  7. My favourite fault of that type is when PHD2 aborts guiding due to a brief bit of cloud, and Ekos decides to abort the run instead of attempting to restart. I think with the Ekos scheduler that's covered, but that requires a bit more forward planning... Autofocus is working well tonight at least. Just starting on an hour of blue now, then on to a bit more Ha if I can soldier on for another hour - still got to power on and lob the cover on after. What I'd give for an obsy with an automated roof...
  8. Single 900s Ha frame, just calibrated (poorly - I don't have a 900s dark to hand) and histogram+curve'd. Definitely a "oh right, everything is working and the skies are good" moment...
  9. Transparency and seeing both surprisingly good here. Really starting to think about a decentish cheap scope for visual while the imaging rig runs - the 10x49 Opticron monocular isn't too much use, especially since I can't keep it steady enough!
  10. Really good skies here. All setup and running on the Bubble Nebula for the night, LRGB. Had some interesting polar misalignment, given I've done nothing but put the scope cover on and take it off again - longing for a nice solid bit of concrete and some better fine-adjustment knobs than what Skywatcher provide!
  11. Love of that analogue film grain? Honestly can't think of any. I suppose it's arguably a cheaper way to get to very wide "sensors" e.g. medium format, but with a tonne of downsides!
  12. Sorry for the spam, anyone notified to replies - but thought I'd conclude after a long night of imaging. I've added some Celestron anti-vibration pads to the steel tripod, so had to re-do my PA from scratch; I did a rough PA with the Polemaster which PHD2 static reckoned was >16' out. I then used PHD2's drift alignment mode to align, with estimated error in alt and az over a couple of minutes falling around 1-2'. I re-checked with the guiding assistant and had an estimated error <3'. Last but not least I rotated my tube to set my focuser pointing straight down, towards the counterweights, to help radial balance, and spent a half hour getting the tube balance in RA and Dec as good as I possibly could. I imaged for about 4 hours last night and guiding was under 1" RMS throughout. The RA tracking did still seem to run away occasionally, but this seems to be completely hidden/fixed by the PPEC in PHD2. Either way, I'm getting sharp images at 0.5"/px, so I'm happy! Moral of the story - take your time and use drift alignment.
  13. Well, here's a flat, which has picked up that vignetting and another dust spot lower right. I've jury-rigged a flat generator with a spare LCD monitor I had lying around, which seems to work OK. In lieu of finding any dust, this at least works for calibrating out. The vignetting is actually concerning me more at the moment - makes me wonder if my secondary isn't quite positioned right.
  14. You can, in some scenarios, get better performance - but routers with external, directional antennas are pretty unusual from a "typical home router" perspective (and almost all of the ones you can buy in PC World and so on are actually omnis, even if they "look" directional - it's a nice marketing trick, making the plastic housing look like it's directional). Most home routers, especially those provided by ISPs, use either omnidirectional antenna or a mix of polarised omni antennas (much more common these days with MIMO), but the overall resultant signal coverage still typically provides a null above the router. I've demonstrated that through measurements on several versions of the VM, BT, and other home routers. WiFi is really hard, especially 5GHz, to make meaningful antenna design/alignment designs around - the best bet is to get decent modern kit which has good RF design and preamps, as well as a solid chipset to do beamforming, and hope for the best. The Ubiquiti stuff is good on that front, as is some of the higher-end Netgear and Linksys kit. The BT hub in particular is actually very good, too.
  15. TBH, for cases where it's "just marginal" and a cable isn't an option I'd first reach for a decent external USB WiFi dongle and a (quality) USB extension lead. You can leave that in situ in your obsy where you've got better reception and just plug into it as you would your scope. https://amzn.to/320i95f and https://amzn.to/2NskUIq are both good ones I've used for this purpose before - the Alfa is particularly good as it has a socket built in, so you can just use a straight USB cable instead of an extender - one less thing to go wrong.
  16. I've been using the Anker ones for a while, such as https://www.amazon.co.uk/Anker-Extended-MacBook-Surface-Notebook/dp/B07L32B9C2/ref=sr_1_6?keywords=anker+usb+3+hub&qid=1566518828&s=gateway&sr=8-6 - there is a LED but it's tiny and easily obscured. I use one of those for everything but the main imaging camera and guide camera (focuser, mount, GPS, mbox weatherstation), mounted on the 'scope tube next to a Pi4 in an old metal housing from Maplin. It's been reliable thus far. The Startech ones are good; for on-mount the chunky industrial ones are probably fine.
  17. Directly over the existing antenna is likely to be one of the worst places to put it - omnidirectional antenna (as featured in nearly all home routers) radiate as a "doughnut", with a null above and below, so directly above is likely to have poor coverage and provide poor signal. Putting additional access points (not extenders, dual radio devices aka mesh access points) within the home closer to the weak spot is the way to go. I've tested probably 10 or so different routers for $work as well as mesh devices with proper test kit in a variety of homes and that's a very consistent finding. But the right answer is always run a cable 🙂
  18. I've not got a reliable mechanism for making flats at present - a Lacerta LED flat box is next on the shopping list once payday rolls around! That's part of what makes this so annoying. Having said that, I'm glad I've not got as many doughnuts as Davey-T 😧 The two-ring pattern is consistent across multiple images/targets - I've not noticed any others, but then I haven't had much light lately! I did take some flats with the t-shirt at dusk approach about 9 months ago but they were free of any dust, so not a lot of use. I'll pop the 'scope off the mount tomorrow - I need to rotate the tube rings around to get the focuser pointing at the dovetail for radial balancing, anyway - and do some flats while I'm at it. Oddly hadn't thought about doing a flat without the rest of the optical train as a means of debugging!
  19. I've got a consistent dust problem in my otherwise (largely) spotless setup, and it's annoying me! Very aggressively crushed image below to shot them, top left of the image: These rings have persisted in the same place for absolutely ages - over a year - and having dismantled my entire optical train I can't spot a single speck of dust. There's actually two rings, a 130px wide one and a 700px wide one. http://www.wilmslowastro.com/software/formulae.htm suggests distances of 8.4mm and 1.58mm from the sensor plane respectively which would be within the sealed camera (I think). It does persist on other filters (above is L). The optical train is: 200PDS telescope Baader MPCC MkIII Baader Varilock adjustable T2 extender set at 26mm from the front of the camera ZWO EFW Mini Two thin delrin shims (spacer to accommodate the ZWO anti-dew heater) ASI183MM-PRO I had a look in the front of the camera but couldn't see anything on the AR window or the sensor itself. Any hints for where to go from here? What else could this be? As an aside, is the vignetting shown in the image above significant? My understanding was that the 200PDS had a larger secondary than the 200P so that for imaging the field would be essentially vignetting-free - it's only slight.
  20. I'll throw in my two cents... I have an i7-2600K - older than yours! I use PI pretty regularly without issue, but did have some slow performance initially which I investigated thoroughly. The biggest single upgrades I made in terms of actual performance were cheap: * RAM - enough to fit a typical stack in RAM, which for me was 32G (about £90) * Storage - getting the I/O unblocked was a huge boost. I used a low-cost NVMe disk (a 970 EVO) and a PCIe adapter (£100 total, I think) PI is fairly CPU-bound on some tasks, but they're not slow. I'd definitely make those two upgrades first, and see how you get on. I've done nothing else and it's perfectly acceptable (most "heavy" ops take <1 min on images from an ASI183MM-PRO). As an aside, if you're going down the Ryzen path, PC3600 CAS-16 is the performance sweet-spot, not 3200. Corsair have new parts out targeting that exact point, as do others. Also, PCIe 4 storage is a thing - it will be most worthwhile for PixInsight, and is fairly cheap for half a tera.
  21. If you've got an enclosed garden then maybe the right upgrade would be to get a scope cover so you can leave it outdoors? Telegizmos ones are very good. SCT and Mak on an Alt-Az or EQ mount is going to be just as much faff to setup, as noted by others.
  22. Well, something worked. I did some final fine tuning of the RA/Dec worm offsets, just to be sure that was all happy - still not 100% on that, really, but anyway. I then made the fateful mistake of looking outside, seeing clear skies, and immediately lugging it all outside! Polar aligned with Polemaster for starters, re-calculating the mount center axis. First run of PHD2 with guiding disabled showed the runaway RA again - not a good start. Guiding assistant couldn't measure south backlash because it never achieved consistent moves, which makes me think the worm tuning might be a bit tight on dec. Polar alignment also reported being 4-5" off, so I did a PHD2 drift alignment - not averaging for a huge period of time but getting within 1-2', after some very minor moves. As I write this, I've been guiding for about half an hour with an RMS error of 1" (.8" RA, .62" Dec) on a fairly low target (Heart Nebula in Cassiopeia) using PPEC/ResistSwitch in PHD2. While that's not quite where I want to be, it's a heck of a lot better than prior, and I'm getting some halfway credible frames out at 240s with a 1000mm f/l. I forgot to re-run the guide assistant after polar aligning so I might be able to get some improvements to guiding by running through that again. It's much more consistent than it used to be, though, so I think that getting the backlash out has made a decent difference on that front. This is all still using the INDI/KStars/Ekos stack. So I think my PA via Polemaster must have been off enough to cause RA issues and I need to practice the art of drift alignment further - here's hoping it's that simple! Edit: Re-ran guiding assistant and got backlash measured OK: Interestingly, despite having fairly good (I think?) PA, as I ran the assistant RA ran off again, heading off to 6" or so off target... Edit: Just for completeness, a 5x240s quick cal-align-and-stack in PI from tonight with a 30 second DBE+histo+curves...
  23. On my old BT line, yes - 125kbps on a good day. Fortunately, replaced that with FTTH about five years ago - I have 2Gbps symmetrical now. Now that half the village has stopped using the copper the old BT lines have sped up quite a lot!
  24. You probably won't get much more range on the new smart hub, I'm afraid - the radiated power limits are as they were. The whole home WiFi units they do are a halfway decent mesh solution, though quite expensive for what they are to buy. The main improvement between the 5 and Smart hub 2 is the mesh capability and QAM256 in the 2.4GHz band (but that probably won't be compatible with your kit anyway - it's very odd, and primarily used for their meshing). The neatest solution in your scenario is a WiFi bridge. This is a box that just, from a networking perspective, acts like a cable - you plug in Ethernet at one end (from your smart hub) and at the other end. You need to configure them and then they're set-and-forget. Because it's Ethernet at both ends you can plug in a switch or direct to a PC. Power is provided usually be a PoE injector at each end. It's been a while since I used the Ubiquiti Airmax stuff but I think you can just act as a client to your smart hub with that, so that'd be a £50 solution and pretty easy to set up, otherwise you'd need two to act as a pair. USB WiFi dongles are similar price points, but won't perform as well, and of course the external unit gives you a lot of placement flexibility (as can USB with an extension lead, but that can be fiddly - USB3 in particular doesn't like extension leads).
  25. Powerline adapters are generally awful. While the link may report 1Gbps, that's just between you and the powerline adapter, not between adapters. Most powerline adapters in best case real-world scenarios can achieve about 100Mbps at best, and are often much worse than this. If your shed is off an extension cable or similar you've got little chance of making anything work nicely. How far away is the shed from the house? WiFi is usually a good answer. Close up just make sure you have a good AP in your house, preferably as close as you can get to the shed; Ubiquiti's UniFi AC LR is a good cheap AP option. If you're fairly far away but can put equipment on the outside wall of house and shed, Ubiquiti do a range of low-cost point-to-point bridges, e.g. https://linitx.com/product/ubiquiti-airmax-nanostation-5ac-loco-wireless-network-bridge-ns-5acl/15217 at £50/end. If you have duct, then running a length of fibre (pre-terminated) is pretty straightforward and definitely is the best option.
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