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BrendanC

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Everything posted by BrendanC

  1. Ah, I wondered when @vlaiv would turn up! The average ADU? Like for example the figure APT shows on its Pixel Aid tool. You're going to tell me I'm doing something ridiculous. I can tell.
  2. Thanks - looks quite convoluted but I'll see what I can do. The reason is that I recently realised I could in theory analyse all my previous data by exporting the file details into Excel, using the time/date to calculate where it was in the sky, and then match that to the ADU value for that specific image. That way, I could get a rough idea of the brightness of different areas of the sky where I shoot, and adjust my exposures accordingly. One side has a lot of streetlamps, the other doesn't, so I'd expect to see the ADU value be higher on the light polluted side, which means in future I could reduce my exposure time on that side to compensate. Or, to put it another way: I just like cool charts of lots of numbers because I might be able to see interesting patterns in them that may - or may not - help me with my astrophotography.
  3. This might be a slightly oddddd question, but I've looked online and can't find an answer. Basically: is there a standalone utility, or feature within another program, that can analyse the ADU values across a set of images? That is, as a batch, to avoid having to do this manually? So, I just point it at the set of images, it goes through them, and gives me the ADU for each image? I've looked at PI's Blink feature, and the quality metrics in software like DSS and ASTAP, but none of them include ADU.
  4. POST-EDIT: The solution is to Extract channels, then just take the red. I guess that's essentially what the Siril and APP settings do, it's just a quick extra step in PI (isn't that always the case...)
  5. Hi all, I'm puzzled about stacking Ha subs in PixInsight. If I stack them in APP or Siril, both of which have explicit 'Ha' algorithms/methods/options/settings, I get decent results (in fact I prefer Siril which is oddddd). If I stack using WBPP in PI, with or without CFA debayering, it's a bit pants. Here are quick examples of what I'm getting, viewed through ASIView which applies a gentle stretch to the FITS files. So, my main question is: when stacking Ha in PI using WBPP, is there any specific thing I should be setting/ticking/activating/switching on or off to get a better result? And my supplementary question is: would you like to see the stacks, so you know what I mean? If so, they're here: https://1drv.ms/u/s!AqovBuVZMwj3lesjCGJLmfm8D_argw?e=MuELbM - about 200MB worth of FITS files. They're all of SH2-198 which is itself a slightly pants object but I had to go with what I could last night. Thanks, Brendan
  6. Cave Nebula. 9:48 hours over 2 nights (15x240s + 12x360s + 7x480s + 4x600s dualband + 36x600s 7nm narrowband) 50 darks per sub length, 50 flat darks, 25 flats Bortle 4, Moon average 84% phase, 46° height Acquisition: APT, PHD2, 130PDS with 0.9x coma corrector, NEQ6, ASI533MC Pro (gain 101, offset 50, -10°C) with 2" ZWO Duo-Band filter and Svbony 7nm Ha filter Processing: APP, Siril, StarNet++, Topaz DeNoise AI, Photoshop
  7. It's yet another Veil Nebula, except this one is made up of nine panels - my biggest mosaic yet. Lots of battles with gradients, and my camera wasn't quite rotated right which meant the crop made the eastern part too close to the edge, but I sort of managed it and can add data to this in future. 24:42 hours over 7 nights (247x360s) 50 darks, 25 flats, 25 flat darks Bortle 4, Moon average 89% phase, 16° height APT, PHD2, 130PDS, NEQ6, ASI533MC Pro (gain 101, offset 50, -10°C) with 2" ZWO Duo-band filter APP, StarNet, Affinity, Topaz DeNoise AI, Photoshop I've also superimposed a Moon (also my shot) to show how incredibly large this object is in the sky, and yet invisible to the naked eye.
  8. Thanks, but the problem is fixed now, see my previous post.
  9. Just to tie this one off, I fixed it. I was going through my mind to figure out what might have changed, for the focus to have moved out. "All I've done is collimate the scope," I thought. Then realised: OK, that might be all I've done, but it's something I've done that might change this. So, I took the primary cell out, wound all the screws down so the primary was right at the very far end, and realised that, over the years, each time I've collimated it, it's moved up the tube a bit. So, now, with the primary absolutely reset as far as it can go, and then recentered, everything is working again. Boom shanka.
  10. If that's like this, then I've been recommended this and have already bought it, so fingers crossed: https://www.firstlightoptics.com/adapters/astro-essentials-parfocal-rings.html (2 inch version)
  11. So, I just took a look at the primary mirror and noticed that, after collimating over the years, it seems to have traveled upward somewhat. So I adjusted it all the way back down and recentered it. This might give me a few more mm to play with. I've also been recommended to get one of these - again, any/all comments welcome as to whether this might work: https://www.astroshop.eu/extension-tubes/ts-optics-extension-tube-m54-8mm/p,71884?fbclid=IwAR2Vks5Lrh7yP7CoZYCVoGM2Qfb2yxERu_2bdEhprrDDcJDelIFPuBMQ21w#tab_bar_0_select
  12. Hi all, TL:DR - HOW CAN I GET 5-10MM MORE OUTWARD FOCUS? So, first night with my new ASI533MC Pro, and I have a problem. I have a 130PDS, and I chopped the focuser tube so that my stars were nice and round. However, what worked perfectly with my previous camera, does not now work with this one. When I focus, the camera is moving out, and I get closer... then closer... then I'm just about there, and then the focuser tube pops out. So it's close, very close, but no cigar. So I need the camera to go out a few mm more to achieve focus. The backfocus distance for the coma corrector is 55mm, which is why I need those spacers before it. Among my many mysterious bits and bobs lying around, I found an extender that looked like it might work, but it's too long. So, this is too short (focus tube adapter then coma corrector then 55mm back focus): And this is too long (focus tube adapter, then extender tube, then coma corrector then 55mm back focus): So I think I probably need a shorter extension tube, to go between the focuser tube adapter and coma corrector? Or, something to go between the focuser tube, and the focuser tube adapter? Does this sound about right to you? Something like this maybe: https://www.firstlightoptics.com/adapters/astro-essentials-t2-m42-extension-tube-set-4mm-5mm-6mm-7mm-8mm-9mm.html, which would give me several options to play around until I get something that works. If that isn't what I need, then if someone could point me in the right direction please, that would be great. I know exactly what I need to do, I just don't know how to do it or even what search terms to use to find what I need! I just need about 5mm-ish more outward room to achieve focus. Sorry, I know I'm probably coming across as a bit of a newb, but this is my first time with this problem so I'm not sure really what the best solution is. Thanks, Brendan
  13. Hmmmmmmmm........! That's very interesting indeed. Don't know how I didn't come across that filter before. Thank you, you might have given me a completely new direction. Oh, and great image btw.
  14. Hi all, Considering a dualband filter to go with an ASI533MC Pro and 130PDS. The L-eXtreme has it all - including the price! The ZWO is cheaper but I wonder whether it's 'good enough'? Because 'good enough' is good enough. Cuiv the Lazy Geek reviews it but only from the specs. Any/all opinions welcome, especially if you have the ZWO (or ideally both). Thanks, Brendan
  15. This sounds like an interesting approach but I'm having difficulty visualising what you mean about using a straight metal edge, aligning that with the spider vane, and then looking at the Concenter. Do you have a diagram?
  16. My Concenter and Cheshire look ok but I'm still getting egg-shaped stars. So, I thought I'd give a star test a whirl, as a precursor to checking for tilt.
  17. Honestly Vlaiv, I can't face it. This has been playing on my mind for four months now. Right from the very start, I could tell something wasn't right, and I've tried so many things now that I'm just going to admit defeat. The ASI533 has great reviews, including from Cuiv the Lazy Geek who is in a heavily light-polluted city, plus I could consider an L-Pro dualband filter for narrowband stuff. Thanks again.
  18. Actually, no need to respond. @vlaiv, you've been incredibly helpful throughout all of this, but I've been through so much pain with this camera, and it looks like there's more to come, so I've decided to sell. I'm going to invest in something a bit easier, like an ASI533. If I still have problems with that, well, I won't know what to do, but fingers crossed I won't. Thanks again.
  19. Are you sure they're not just out of focus stars?
  20. Cool. I also took some more sky flats in the early morning (cos I couldn't sleep) so let me know if you'd like me to upload them too.
  21. Sure, I know what to do, I just don't know exactly what I should be seeing. Basically, should there still be the offset, or concentric circles? It's definitely concentric circles for slower scopes, I just cannot find a defnitive answer to this fairly simple question for faster scopes.
  22. Hi all, I'm having difficulty collimating my 130PDS which is an F5, brought down to F4.5 with the addition of a 0.9x coma corrector. I've collimated it plenty of times in the past, with my Cheshire and Concenter, but for some reason I'm not quite getting the star shapes I feel I should be. So, I want to do a star test, but I'm not sure what I should be looking at when doing it. My understanding is that faster scopes have an offset, and I can see this clearly when I look down the focuser tube. So, should I see this offset when I defocus to do a star test? Or should everything be fully concentric? I've looked around online and opinions differ! Thanks, Brendan
  23. OK, sorry, but I have absolutely no idea about pixel math or how to do any of these things you mention! I just put calibration files and subs into whatever stacking program I'm using and let it do its thing. So, with that in mind, if you could take a look that would be great. This is the link, and it includes 10 sky flats, 10 'normal' flats, a master dark, and a master flat dark: https://drive.google.com/drive/folders/1wt0HEs7_vwI--TeWzWcmMQO7MIKoXgQh?usp=sharing It comes to 312MB unfortunately, and I don't want to break your bandwidth, so if you'd prefer, say, just 5 each of the flats, let me know. Or you could just go into each folder and download only what you need. I should add that it's approaching 00:30 in my time zone and I really need to get some sleep...! Which also means there's no rush to do this, I'm just very grateful for your help.
  24. My understanding - probably wrong - is that Vlaiv was suggesting taking sky flats, then stacking them by calibrating them with my other flats, as if they were lights. But I don't know how this is possible. How do you calibrate flats with some other flats?
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