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michael.h.f.wilkinson

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Everything posted by michael.h.f.wilkinson

  1. That's a wrong comparison, because it suggests a big scope cannot be equipped with a modern sensor. Besides, to quote Scotty: Ye cannae change the laws of physics, captain". A big instrument captures more photons and has a higher resolution than a smaller. My APM 80 mm F/6 triplet is optically outstanding, but cannot match the resolution the 8" C8 has on planets. There is simply no contest. A 30mm scope will not show as much detail as, and will capture 4 times fewer photons from the same area in the sky than a 60 mm, this means the S/N is half as good. Resolution-wise, a little 30 mm lens will not be able to capture the moon like this: Click for full resolution. No amount of AI-driven enhancement will change that, simply because the information isn't contained in the data. A colleague of mine showed a paper in which it was shown that a deep-learning-based sharpening method on astronomical data hallucinated several objects (i.e. created objects out of noise). Whilst adding some freckles, or misplacing hairs in AI super-resolution applications to old portraits is quite tolerable, in scientific or medical imaging this kind of creativity is unacceptable.
  2. On my other monitor I notice a bit of a ringing effect on Jupiter in particular. Will do a reprocess later
  3. Interesting, especially for large targets, but for smaller targets there is no replacement for aperture.
  4. Had a quick bash at Jupiter before it got too low behind the trees, and was able to catch a bit of shadow transit Seeing wasn't brilliant, but at least I didn't get too much in the way of clouds I then turned to Mars, which was higher in the sky. The first shot, taken at 20:18 already showed some nice detail The second was taken almost two hours later, at 22:10: I think I can make out Olympus Mons and Alba Mons in the north. All pictures taken with my Celestron C8, with Siebert Optics 1.3x Tele-Centric and ASI183MC camera. The Jupiter shot is a stack of 20% of 9000 frames, the Mars shots 20% of 10000 frames and 40% of 20000 frames respectively.
  5. That is really good. I am hoping to have a go tonight. Fingers crossed
  6. Indeed. The 183MM yields this with the same 135mm F/2 lens and an H-alpha filter The ASI183MC (non-cooled) yielded this with 4 h of data on my Meade SN6 6"F/5 Schmidt-Newton
  7. I also have a cooled and a non-cooled ASI183, and rather like them. Might go for a bigger sensor at some time, but for now they will do. I also still have a modded 550D, which can produce some nice results, despite its age, especially when paired with the Samyang 135mm F/2.
  8. Callig it a game changer is a bit much, I agree. At a similar focal length, and lighter weight, I will stick with my Meade SN6 6" F/5 Schmidt-Newton. It was also ridiculously cheap. Correction perhaps not quite as good as a top of the line apochromat, but at twice the light gathering capacity, and no diffraction spikes it makes me wonder why SN6 was discontinued. I am sometimes tempted by various Mak-Newts, as well
  9. I had a similar mount and telescope (4.5" f=500 Newtonian, now refurbished as mini-Dob). The mount isn't that stable, but after changing the aluminium legs with home-made hardwood legs, it was a lot better. More details here: I ultimately ditched the mount (which I didn't really need, as I had a perfectly serviceable Great Polaris mount), and put a mini-giro manual alt-az mount on it
  10. In that case you'd better not practice the fleckerl in the Viennese waltz as I did yesterday
  11. I just worked out that in the sixty years (and a bit) of my life so far, the earth has moved just over one third of a arc second in its orbit around the centre of the galaxy. Should I reach 85, that will go up to about half an arc second. Since Galileo's birth, the centre of our galaxy has moved just under 2.7 seconds of arc with respect to distant galaxies. A bit of a pale-blue-dot moment.
  12. That is a lovely kind of set-up. I often use my APM 80mm triplet with a 2" Amici prism and the Nagler 31T5, yielding 5.3 deg FOV at 15.5x magnification. I did a comparison with the views in a pair of Helios Apollo 15x70 bins here: The bins have the definite edge in portability, but the 80 mm triplet beats them for visual impact
  13. Had a bit of a struggle today, but at least got some result. Clear skies were replaced by clouds the moment the entire set-up was ready to go, but I persevered, and waited for the skies to clear. Indeed, 30 minutes or so later the sky was clear enough around Jupiter, so I decided to give it a go. Seeing was choppy, but I got a series of SER files before the next batch of clouds popped by. I waited some more, whilst doing a quick process of one or two files (with mixed results). Once the sky was clear again, I gave it another go, but the seeing was considerably worse, and with more clouds threatening, I gave up the idea of waiting for Mars to rise above the trees to my east. As it turned out, the first SER file I took was the best: Not brilliant, but better than nothing I suppose. Equipment: Celestron C8 on Vixen Great Polaris mount, with Siebert Optics 1.3x Tele-Centric, and ASI183MC camera
  14. An astronomer I know and I discussed the option of imaging Jupiter with the Gran Telescopio de Canarias (10.4 m, and he had observing time on it), with a very fast multi-band imaging device (HiPERCAM). He had observing time available, and all we asked for was 5 minutes, but the powers that be decided against it. The problem is that even with very short exposure times, freezing the seeing is not straightforward on such a big instrument, according to the technicians of the observatory, as you are requiring a much larger part of the sky to stay put. We were eager to try it in any case, but ultimately didn't get the green light.
  15. Had a quick lunch break outside with the Coronado SolarMax II 60. Apart from quite a bit of activity on the disk, with some nice spots, plage areas, and filaments, a huge array of proms was visible on the right-hand (eastern) side of the disk. A smaller prom could be seen at the eight o'clock position. Several students joined me to have a look, so it was a nice little outreach event.
  16. That is very nice. Very natural look with loads of detail
  17. Nice image despite conditions. What equipment did you use?
  18. I would have a look at the beginners telescope section of FLO (see link in banner). There's a lot of good advice there. I would think the Sky-Watcher Heritage 100P ticks a lot of the boxes. I am not sure what you mean by ability to connect to a phone. If you mean you want to control the telescope through the phone, that is not possible with the cheaper systems, but there are phone adapters to attach the phone camera to the telescope.
  19. Celestron C8. Twenty-seven years old, but still going strong.
  20. Clear Outside and other services had been predicting a beautiful clear night for tonight for a while now, so I set up the scope outside early, for it to cool down properly. Around 20:00 I set about polar aligning the scope, and looking at Jupiter. I noticed the collimation was off. I got decent views in the Nagler 31T5, but the Pentax XW 10mm gave mushy views, not due to seeing (which seemed really good). I set about collimating the scope, which is always a bit fiddly, but after tweaking the secondary perhaps 5-10 minutes I found the view in the XW 10mm was now great, with the GRS nicely centred on the disk, and the thin ellipse of lighter hue surrounding it crisply outlined. I even went up to 254x with the Delos 8 mm, and still got nice stable views. All seemed set for a fruitful planetary imaging session, first Jupiter, which is not too low any more, and then later Mars, which rises really high. And then clouds intervened . I had noticed one or two wisps of cloud passing, but was still firmly convinced that these would pass. Now, however, a solid belt of cloud came out of the east. Checking Clear Outside to see if this was merely a thin belt, I was disappointed to see that the forecast had changed to clouds for the rest of the night. Nothing for it but to pack it all up and go inside. ☹️ Oh well, at least the scope is well collimated again, and probably will stay so for years, if the past is anything to go by.
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