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Peter Drew

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Everything posted by Peter Drew

  1. That should be plenty good enough for the focuser alignment on a F10 refractor. It still doesn't guarantee that the objective cell is square to the main tube. This would be obvious in a star test eventually. As long as nothing is actually broken, all else is fixable.
  2. The dewcap or even the objective cell does look to be skewed. I actually have one of these, the dewcap does pull off revealing the screws that secure the objective cell. I would loosen these and then press the cell into contact with the main tube and then retightened in position. I think the offset laser spot is more likely to be due to the focuser end being out of square, this can be corrected by the same method as that of the objective.
  3. All a bit of fun, contemplating what to do to combat an inconsiderate neighbour but mostly, to implement any such suggestions, would only exacerbate the situation and the OP is the one that has to live with the consequences. The best thing to do is to bite your lip and carry on as best you can, eventually things cool down and hopefully the neighbour might take notice of the soaring electricity bills. From a security aspect, I would sooner have a neighbour physically outside at night as a much more likely deterrent than a row of "helpful lights.
  4. If the views through it look ok, it probably is. Difficult to tell the mechanical alignment from close up, a photo showing the whole telescope length would be helpful in this respect.
  5. @soluara. Moon, planets, double stars and solar won't be much affected and I would recommend that you continue to do this as it will demonstrate that the neighbour has not "won". Also, continue with your considerate approach however tempting it is to fight back, it maintains your high moral ground and the long term effect of this can often work in your favour. Good luck.
  6. Careful that this doesn't create another issue!
  7. For me, binoviewing for solar, lunar and planetary provides a big upgrade in visual performance and enjoyment. Bright DSO's also look more submersive albeit dimmer than monovision. Not everyone gets on with binoviewers though, best to try before you buy if possible.
  8. This is true, but I think the summation effect that tends to enhance the brightness of a binoscope above that of a single unit may also apply to the summation of the two exit pupils of a binoviewer such that the light loss appears to be less than half. Also, some binoviewers split the light nearer to 60/40 which again gives an advantage over 50/50.
  9. Apologies for multiple posts, don't know what went wrong there?
  10. I've built more than 20 binoscopes over the years, both reflecting and refracting so have no qualms about building any size, the main limitation is cost!. I do have a spare 18" F3.6 mirror, it's tempting to get another made. I have not found it necessary to use coma correctors on my 12" reflecting binoscope despite the off axis images being compromised. When you use a binoscope you generally concentrate on the central image and the periphery is just a perception, the eye has a very small field of definition and resolution. Try looking at a page of text without moving your eyes and you will find that it is difficult to read more than an extra word either side of it, the same goes for stars in a binoscope.
  11. I've built more than 20 binoscopes over the years, both reflecting and refracting so have no qualms about building any size, the main limitation is cost!. I do have a spare 18" F3.6 mirror, it's tempting to get another made. I have not found it necessary to use coma correctors on my 12" reflecting binoscope despite the off axis images being compromised. When you use a binoscope you generally concentrate on the central image and the periphery is just a perception, the eye has a very small field of definition and resolution. Try looking at a page of text without moving your eyes and you will find that it is difficult to read more than an extra word either side of it, the same goes for stars in a binoscope.
  12. I've built more than 20 binoscopes over the years, both reflecting and refracting so have no qualms about building any size, the main limitation is cost!. I do have a spare 18" F3.6 mirror, it's tempting to get another made. I have not found it necessary to use coma correctors on my 12" reflecting binoscope despite the off axis images being compromised. When you use a binoscope you generally concentrate on the central image and the periphery is just a perception, the eye has a very small field of definition and resolution. Try looking at a page of text without moving your eyes and you will find that it is difficult to read more than an extra word either side of it, the same goes for stars in a binoscope.
  13. I've built more than 20 binoscopes over the years, both reflecting and refracting so have no qualms about building any size, the main limitation is cost!. I do have a spare 18" F3.6 mirror, it's tempting to get another made. I have not found it necessary to use coma correctors on my 12" reflecting binoscope despite the off axis images being compromised. When you use a binoscope you generally concentrate on the central image and the periphery is just a perception, the eye has a very small field of definition and resolution. Try looking at a page of text without moving your eyes and you will find that it is difficult to read more than an extra word either side of it, the same goes for stars in a binoscope.
  14. Here's another related thought. It is usually advised that if the telescope's exit pupil is larger than that of your eye, then the aperture of the telescope is effectively reduced. On that basis, when observing a bright Moon, presumably the iris in your eye stops down to its minimum aperture, surely this could be effectively stopping down the aperture of the telescope?
  15. Welcome to SGL. Sounds as though the tube is unbalanced and front heavy, the higher the tube is raised, the less the effect is. Have you left the cover on the front for this test?
  16. Send yourself an email congratulating you on winning a (telescope of choice) and keep the ensuing expense secret.
  17. Poor seeing is better than no seeing.
  18. The largest Dob I've heard of in Europe is around 40". VCSM in N. London can coat mirrors to at least 30" as they have done ours a couple of times over the years.
  19. The camera is underwater, hence the mushy image.
  20. Definitely in OOUK livery rather than OOUS. The length of the tube suggests that the "L" could stand for long focus.
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