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discardedastro

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Everything posted by discardedastro

  1. Welcome! Straight in at the deep end, it looks like! I won't comment on telescope/camera selection - there are others who can cover that much better than I. Piggybacking is fine but does usually put you into quite an expensive category of mount - think Mesu, CEM120, Losmandy, 10micron etc, £3-4k and up - if your scopes have "reasonable" aperture. Consider if you'll be doing both year-round or sticking to planetary/lunar in brighter months or not, e.g. swapping scopes every 6 months rather than piggybacking. I'd strongly recommend getting some of the software and e.g. motor focus, gui
  2. It does help, but I've since aded a tilt adjuster to the train. Haven't adjusted tilt with it yet, but at some point I'll get around to it! I'll also add here - in case it's handy - that TeleVue helpfully confirmed on Twitter that with the T2 adapter fitted, there is exactly 55mm from the top surface of the T2 adapter to the focal plane.
  3. I've been doing RDC protected 4-gang onto a 12V PSU (a Nevada linear one) for years without issue, so that works. With a reasonably large box the PSU can sit in the box - just think cooling, esp with the linear PSUs. However, with a good battery, you can indeed just plug that in - and a USB hub looking for 12V will also be fine off a 13.8V battery input, "12V" in consumer gear almost universally means 12-ish-or-what-a-12V-battery-spits-out-V. I use a silicone cable from Lynx Astro to go to a cigarette lighter socket on the PSU or an adaptor to a battery via crocodile clips.
  4. High efficiency just means not-terribly-lossy - it has no real bearing on this (other than being another part that's losing you efficiency and liable to fail). Boost-buck converters don't really fix undervolt issues; I've got some scope graphs somewhere, but broadly speaking these sorts of converters tend to completely blackout when they get overloaded or the input voltage drops too low, and you end up with short transients down to <2-3V or "choppy" power. The right way to avoid undervoltage issues is a suitably dimensioned battery or power supply. The overall price will be the sa
  5. Single supply is fine. I will say those boxes branded "NVVV" are trying to rip off MeanWell (branded MW in a quite stylised fashion on their units), who are a well-regarded manufacturer of SMPS. I'd stick to the real ones, e.g. https://uk.rs-online.com/web/p/embedded-switch-mode-power-supplies-smps/7059857/ - a little more dear, but you don't want a dodgy PSU blowing up all your kit when it decides to short the incoming AC across the DC outputs... Any of those encapsulated/skeleton PSUs will indeed need boxing up, but that's very doable - just consider heat dissipation (you may want to th
  6. Pretty sure the obstruction will be larger - the oversized secondary to avoid vignetting was a definite feature of the DS models. Back focus on the 200PDS at least is plentiful but with a decent extension tube (the Tele Vue ones are great, but others are available - just do upgrade from the Sky-Watcher one!) that's no issue really, and if you swap the focuser for something a bit nicer or put e.g. Baader Clicklock on the focuser that takes up a good amount of backfocus anyway, and you'll probably want a coma corrector eventually which will take up a bit more...
  7. Right - but binning 3x3 the same images and creating copies then stacking doesn't actually put the different offset pixel data into each of those created subframes, right? ImageJ plugin would be good to see if for no other reason than reference, certainly. There is definitely scope for reuse if I ever decide to swap the 200P setup for something a bit more considered - it's a good camera, just needs to be paired with something a bit better suited to it and an 80mm frac would certainly fit the bill. That's a lovely shot.
  8. That makes some sense practically (though I'm still trying to get my head around the maths of it - basically the same logic as binning, right?) - and I agree I'm unusefully oversampled. I'm not sure how I'd go about making that work, though, in terms of actually generating those subsampled subframes from my current data. I'm predominantly using PixInsight at the moment for my processing, but I could probably hack something together to generate this with astropy.
  9. Hi all, So I've now "finished" my 200PDS rig - it's the best-corrected I can make it with a Paracorr, collimated nicely (though I do want to get a Catseye autocollimator to "check"), and the imaging train works well with good guiding. The 183MM-PRO is a nice camera that's worked well for me for a long while now. I'm only interested in AP for this rig - I'm treating visual as a separate set of requirements involving a large Dob at some point. Trouble is, especially with the mild Barlow effect of the Paracorr, this is a pretty narrow-view scope now. The AFOV is about 40x26 arcminutes,
  10. Might be gin here rather than wine, but I recognise that vibe! I was wondering about a VX12 or 14 as a visual counterpart to my imaging rig (a 200P Sky-Watcher) but am erring towards a frac (either a cheap Bresser or a low-end Tak) at the moment just for portability and ease of setup; not having to collimate after moving etc is a definite appeal, but then I'm limiting myself to fairly bright targets with reduced aperture, so swings and roundabouts... I've got a E350 estate which would be big enough to move a VX14 should I go to a dark sky site, but definitely worth considering the si
  11. Just a night and a bit of data inbetween fixing observatory issues, and not perfect by any means - I tried a new process using WBPP in PixInsight and definitely didn't get as good a result. Framing-wise the Iris isn't ideal for my setup but it does get some nice detail near the central star. Shot on the 200PDS with my usual setup - Paracorr, ASI183MM-Pro, EFW with Baader filters, ASI174MM and ZWO OAG on an EQ6-R Pro. INDI/KStars/Ekos for capture, and PixInsight for processing. I couldn't find good "background" bottom right which I think limited the options for DBE - it's a tricky one! See
  12. I think so long as the screws are replaced (potentially with shorter equivalents) you'd be fine. You just want to stop debris getting in.
  13. I should add that the telescope has a Pi 4 on it (mounted in a little case on the tube of the 200P with velcro tape) running INDIserver which is the "other half" of the equation - this has been running flawlessly for a couple of years. I used to run Windows/APT and then SGP back in the day but kept coming back to Linux for the remote management and monitoring. RDP is definitely better than VNC, which is the big "win" over Linux for remote operations, but everything else I really do prefer Linux. Ekos/KStars has come a very long way over the years, too.
  14. So, for a good long while - going on 3-4 years - I've been using a spare laptop as my observing control PC for imaging. However, if I ever get around to an observatory I'll need something full-time and the laptop takes up a lot of space to have out all the time. I figured I could do pretty well with the Pi4 so set about making an ideal "Obsy in a box" setup. This comprises: Pi4 8G - 4G probably more than enough but best to futureproof ArgonONE case - an excellent, passively-cooled (but fan-assisted, i2c controlled) aluminium case, with... ArgonONE M.2 SATA to USB adapter
  15. Does look good - I've had the cheap Skywatcher one for a while and as a more ahem rotund gentleman of ample proportion, find the clamps slipping rather alarmingly when the pipes get a bit dewy and wet. Something with fixed positions appeals a lot! That's a lovely setup overall.
  16. I have an Ethernet cable certifier at the office and a favourite hobby is seeing how hilariously badly flat Ethernet "Gigabit ready!" cables fail against the standard for even Cat5e. Vast majority of them aren't even differential pairs, they're just four wires shorted together, or so close in RF terms the certifier can't tell them apart... Definitely recycle 'em if you ask me - life's too short for bad cables!
  17. So, an interesting occurrence today - I fired up the telescope and upon trying to connect to everything realised I was not finding the main camera. The USB2 filter wheel is plugged into the hub on the camera, and this was being discovered occasionally by INDI. Looking through my system logs I kept hitting log messages like this: Feb 18 18:57:44 raspberrypi kernel: usb usb2-port2: Cannot enable. Maybe the USB cable is bad? Feb 18 18:57:49 raspberrypi kernel: usb usb2-port2: Cannot enable. Maybe the USB cable is bad? Eventually I took the kernel's advice to heart, grabbed a spar
  18. The mount will draw as much current as it needs from any source between 11 and 16V. Most 12V stuff regulates that voltage down to 5V or 3.3V for any internal electronics (since 12V microcontrollers etc basically don't exist), so will tolerate a wider range of input voltages than precisely 12V. 12V is generally taken to include the range of voltages a 12V lead-acid battery or charger will normally supply, which will be somewhere between 11 and 15V. Normal "float" levels for a charged 12V battery are around 13.8V, which is why many "12V" supplies actually target this with their output to accommo
  19. Doesn't look problematic if it's consistent - I'd check a range of samples and try a few different methods for covering it and exposure times.
  20. I'd avoid the no-name stuff from Amazon. Pretty dubious in terms of what you're getting. The challenge with your budget is that when imaging with a prime lens/bigger sensor like you've got there the cost will normally be much higher than 1.25" filters etc - filter cost broadly scales as a function of coated area! I'd save your money, wait a bit, and get an IDAS D1 or D2 in EOS body-mount format (though check the 550d can take these): https://www.firstlightoptics.com/light-pollution-reduction-imaging/idas-body-mounted-filters-for-canon-eos-aps-c-and-rp.html These will be muc
  21. For what it's worth, I don't use PS at all for any of my images - PI can do everything I want. Probably the only thing I'd use PS for would be watermarks/signature image addition. Depending on what your source material is you've probably stretched with HistogramTransformation while you had a STF applied. Super easy to do depending on what your starting point was (linear vs nonlinear, starting exposure levels, etc).
  22. It's one hell of a learning curve - but it will let you produce some utterly fantastic results and does absolutely blow every other package out of the water in my opinion. One common mistake with PI is leaving STFs enabled - hit F12 (you'll see the green band on the image label if you've got an STF applied). The screen transfer function effectively tries to stretch data so you can see it but can cause confusion in post-processing. I'd heavily recommend Inside PixInsight as a book reference. It's full of good tips and clear explanations of tools - it is the missing manual. You've
  23. Right - but if your 200P is the same construction as mine (open at the back to the back of the primary in cell), the primary doesn't completely cover the rear of the tube and the primary cell has no baffling to the sides. So light can bounce around the primary/cell, enter the tube at an angle, and cause diffuse artefacts in dark frames taken with the front and drawtube covered. Note the coloured "rays" top centre of this image which are a result of mono image stacking causing the light (in my case from a neighbour) leaking into the tube to appear in different places per filter. I'm at a differ
  24. I'd spend some of your cash on PixInsight, and "Inside PixInsight" (book). Save the rest towards an imaging camera or a cheap guiding setup.
  25. The 200P will absolutely create this sort of artefact if you apply light behind it. I can't find the post on SGL but I blogged on a similar issue - I confirmed and diagnosed with a coat over the scope's various potential light paths but you could do the same thing with your shed light with darks to be sure. https://www.talkunafraid.co.uk/2019/02/how-to-fail-at-astrophotography/ The fix is to cover the rear - you can do this with fabric and tape or do what I did and drop a black plastic insert over the back, using the locking screws to secure it in place. If you want to get paran
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