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ollypenrice

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Everything posted by ollypenrice

  1. We have four square topped piers in one of the robotic sheds and they can snag cables. The fix is easy: attach strips of metal pointing downwards and, if you like, reaching in to the column. These simply stop the cables hooking under the corners of the top. For anyone designing a new pier, though, I would advise against square tops in the first place, or certainly ones which overhang the column. Olly
  2. That must, indeed, be low for you but the result is superb. The blue nebulosity will be the worst affected - but there it is. Gorgeous object. Olly
  3. Well done, Carole, and best wishes to Kev's family. Olly
  4. No, don't apologize. It turns out that the question carries a lot of baggage which is hugely location-dependent. It's interesting to discover that the world is not homogeneous! Olly
  5. Risk? How would you feel about traveling overland at 118 feet per second (36 metres per second?) Take a quick look at something 36 metres away and say to yourself, 'One second.' That is what we do when we travel at the motorway speed limit in France. And we are worried about looking through a telescope at night? This is not a rational risk assessment. Olly
  6. I think this 'personal protection' thing is getting pretty weird, folks. If you go for a fight, how will it end? Any weapon you have may be turned on you, or another produced, and up goes the ante. By the far the best weapon to have about you is none, then it won't escalate. You are more likely to be attacked at a cash point - but how likely is that? Olly
  7. I should just add the the boar hunters are certainly dangerous and shoot both each other and members of the public every year. The risk to the public is only about one in fifty million, though... lly
  8. Make a noise and the boars will run away. Only an injured boar presents any kind of danger and they are usually on their own. Olly
  9. This just comes down to good old fear of the dark. You're in far more danger driving to your site than observing at it. Certainly this is true in Britain and Europe where 'personal protection,' American-style, is illegal. We learn or inherit fear of the dark but it's an irrational fear since the daytime is far, far more dangerous. When I came to my present place, a dark, remote farmhouse in rural France, I would sometimes feel spooked in the night. Now I never do because, I think, I've 'unlearned' this irrational fear. While I would love to see wolves or boar at night - they are around - I kn
  10. This isn't called galaxy season. Not by me anyway. Galaxy season is over, for me, by the month of June. That's at Lat 44. Olly
  11. Don't confuse seeing with transparency. They are not the same by any means. 'Seeing' refers to the optical stability of the lightpath through the atmosphere. Does a beam from the object get stirred up on its way through? If so the information arrives in an already-blurred condition. The finer your sampling rate in arcseconds per pixel the more damage this does and it can very quickly become your weakest link. (Fast frame solar system imagers fight back by taking hundreds of very short subs and retaining/combining just the lucky ones which enjoyed a moment of stability.) Transparency, though,
  12. I think it's equipment-driven up to a point, but only up to a point. If we take the example of any equipment setup, fix it and call it 'observatory x,' what variables remain? Ooooh, lots and lots. What target do you go for? How do you lay siege to it? Will it be a mosaic? What filters will you use? How will you blend them? How will you process the data? The million dollar question! So I don't think AP is equipment-driven, I think it is processing-driven. Olly
  13. The distance between the flattener and the telescope can be (and is) adjusted by the focuser so the distance in question is between the flattener and the camera. Olly
  14. The resolution in arcsecs per pixel which Vlaiv, rightly, makes the benchmark for discussion is controlled by the focal length and the pixel size. You can pair a shorter focal length with smaller pixels or a longer focal length with larger pixels and get the same sampling rate. My experience is that the advantage of a very large scope with large pixels over a much smaller one with smaller pixels is far less than one might expect. (I'm not talking about going to professional-sized instruments but, in my case, I'm comparing a 14 inch ODK and a 5.5 inch refractor.) Added to that, large pixels ar
  15. It is a bit odd for the reasons you suggest. Could it simply arise from a change in local conditions? The seeing going off during the red sequence? (This assumes you did each colour in a block rather than scrolling RGB,RGB etc.) Olly
  16. France and the UK both use DST (unfortunately) but France is always an hour ahead of UK time. Could this be your problem? (I'm in France as well.) There was a bug in the GPS time signal affecting older Meade GPS mounts. I vaguely think this raised its head in 2018 but can't be sure. You can risk updating with a fix but I found with my own elderly LX200 that the whole alignment process was far quicker, easier and more reliable with the GPS functions disabled. Olly
  17. Our system does have soft start and stop built into the mechanism as supplied. Olly
  18. I suggest a planisphere, a simple device which gives you an instant idea of what is in the sky on what night. Unlike a mobile phone, it has a large enough surface to show all that is up there. They are also very cheap. Astronomical observing is much more interesting if you know something of the science behind the faint smudges we see at the eyepiece, so a book on the basics would be a good idea. You know your son best so browsing at a large book shop, hands on, would let you see whether a given book would suit him. Olly
  19. Gnu South Wales: very good, very good! I nipped outside and captured this snap of... Gnufoundland. Olly
  20. Cue for my astronomical wingspan joke: Why does an albatross have a twenty foot wingspan flying south and a ten foot wingspan heading north? . . . . . . . Olly
  21. Blue wildebeest are gnus to me. Olly
  22. Quite honestly, a lot of lunar photographers couldn't tell a gnu from a wildebeest. Olly
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