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  2. Thanks John. If the old shape 4mm was good in your 300mm, then that's good news. It is a good shape and feel. It is a shame there aren't more, they're an excellent price.
  3. Thanks for sharing. I didnt have time to download the data and stack it but I tried to remove the LP gradient from your image:
  4. Thanks Chris, yes it is very nice from what I can tell so far. Very manageable tube which is not what I was necessarily expecting, should be good! Gavin has kindly offered the TEC160 for that job John! That might be a little unfair on a 200 quid scope but will be fun! Focuser is not the best, but seems perfectly adequate for the job. Smooth and precise enough. It is an 18% secondary obstruction James, so contrast should be very nice. It does look tiny!
  5. I had my bilateral laser iridotomy done today. Wasn't looking forward to it, but it wasn't too bad. Have to use eyedrops for two weeks and no contact lenses meanwhile. Fingers crossed this has done what it is supposed to. Carole
  6. Both the cooler and heater heat exchangers can be simple CPU heat sinks. 3D printed ducting could carry the air round the system. The air coming out will be warmer than the air going in due to the inefficiency of the Peltier TEC but warmed air is what we want for feeding up into the dome to stop dew both outside and in (though the dehumidified air should not contain much moisture). Seems to me this doesn't need an particularly efficient Peltier TEC and the ultra cheap Chinese ones should do. It only needs to cool the air below dew-point. I wonder if I can make this small enough to put inside the ASC casing. A small tube would be all that is required to take the condensate away.
  7. It amuses me that the secondary looks so tiny :) James
  8. Hi, This is wrong what you are thinking. The need for adding extra weights laterally does not come from the mount . It comes from asymmetric weight distribution of the telescopes or the equipment you put on top if the saddle plate. For example a reflector with a attached finder scope will always be heavy to one side if you do not put the finder scope exactly on top of the scope, but then you will not be able to look through the finder scope That is the reason why people add extra weights in different positions. regards Rainer
  9. Visual acuity, experience, and perhaps even "just knowing" where the stars are must make a big difference. It would be interesting if they also asked for peoples' ages when the figures were submitted and made some attempt to rescale the numbers based on that. On the other hand, if the majority of the respondents were perhaps old codgers whose vision isn't quite what it used to be (and I may be in that group :) , who's complaining about the problem looking worse than it actually is :D James
  10. I'm selling my eq6 because upgraded it to a Cem60. I've spent the last few days setting it up. I've got it mounted on the Tri-Pier which is very solid, much more so than the eq6 tripod. As to balance, I was worried about that. I've just finished balancing for the moment but I made sure the focuser on the scope was close to the eventual position for my camera etc. There was some tendency for sideways movement when in zero position which I fixed by rotating the focuser slightly and fiddling with the filterwheel and finderguider until everything stayed straight. I was also quite surprised how much having the focuser 2.5 cm out had on Dec balance. I ended up having to put a Primiluce balancing weight on the objective end without the counterweight! I've never had to do that with my 4 inch refractor before. The saddle plate is very long which could cause issues with motorfocus brackets. Now all I need is a clear night to polar align and fine tune my focus so I can check balance again! I wanted more payload to run two telescopes and cameras eventually.
  11. There's a location near here where someone reported 45 stars. I'm struggling to credit that, I have to admit. It might be interesting to look at what kind of magnitude stars we're getting down to for that sort of figure. James
  12. Great looking scope Stu It would be very interesting to put that up against a top 6 inch apo refractor. It looks like it's from the same era as my 12 inch. The focusser and extension tube on your scope are the same that my 12" F/5.3 came with originally.
  13. There is another SGL thread on this: I agree that the data is very inconsistent and rather inconclusive.
  14. Oh Stu, a 8" f/8 with 1/10th wave! It can only be wonderful. Looks amazing too! Congratulations :)
  15. Agreed, around me in the outskirts of SW London if the results are to be believed the sky goes from Dark skies to Very severe light pollution...... In reality it varies a lot due to the atmosphere, time in the evening, where the moon is, and where in the sky the object you are looking at is (if it is fairly overhead you are in business). With a CCD I can easily get below mag15 so I'm happy.
  16. The app is simply duplicating the hand control functions so Just follow the procedures from the hand control manual.
  17. Perhaps because fewer people own DSLRs these days thanks to phone cameras, so buying a dedicated astro camera seems more logical than a DSLR that wouldn't get used for anything else anyhow? Though personally I think I'd almost always use my DSLR for really wide field shots, at least until I can afford something with a sensor of a similar size. James
  18. More food for thought, thanks. My plan to copy John's idea for my 10" GSO Dob has been scuppered by the lack of the smaller opening in the 10" top cover. No worries, though, I'll take Ben's suggestion and get a filter for my 127 Skymax. (I'm dangerously tempted by a PST though, I made the mistake of viewing some of the youtube videos of them, together with their results !)
  19. The trend seems to be moving towards dedicated CCD /CMOS astro cameras. Keeping up with the proprietary DSLR interface changes as new ones come out is tough for developers.
  20. The simplest dehumidifier would be to blow the air through packets of silica gel which would need replacing every so often with fresh or dried packets. However, experience has shown that the silica gel gets "full" pretty quickly even with the air indoors. The other way is to cool the air below dew-point so that the water condenses out. I could do this with a Peltier TEC. Of course the dried air would then need heating otherwise the dome will be cold and dew will condense on the outside. I guess the cooled and dried air could be passed through a heat exchanger on the hot side of the Peltier TEC and warmed up for feeding up into the dome. This would become a combined dehumidifier and dew heater. Hmmm... I wonder...
  21. Thanks Shane, It is gradual, in a similar way nebulae and galaxies reveal detail gradually. I don't really stare directly at the planet but let my eye naturally scan the disc. That way subtle detail can often flit in and out of view as the turbulence comes and goes. Obviously, its not easy to accurately place features on such a tiny disc, so the sketch is just a rough representation of how things may appear in a small scope at high power.
  22. Haven't got much done this week, but over the last couple of evenings I've been tidying up in preparation for painting the scope room, which I hope my daughter will help with tomorrow. I even took a hoover down and to get rid of as much of the dust as possible. Disappointingly the removal of the dust revealed this: Looks like a rodent of some variety has been nibbling at the edge of the floor I'm slightly tempted to get some steel or aluminium angle and screw it over the edges, though clearly I'm going to need to put some "rodent deterrent" down there somewhere. Last job this evening was to remove and number all the pieces of aluminium section for the lighting. They can go back in once the painting is done, but taking them out makes the whole job a lot quicker and simpler. James
  23. Nice work. Big thanks for sharing your data. I certainly need to practice more. I have downloaded your files and tried processing using APP and PI but I am really struggling to handle the light pollution. Your final image is way better than anything I can do with your data so far, well done.
  24. Today
  25. Thank you. I updated firmware before I turned the mount on. As for the manuals, there is no manual describing app functions and alignment methods. It appears that there is no quick solar alignment, but at the same time I have no idea what point and track is and how it works. Celestron has solar system alignment and it works beautifully, no need to point north, just level.
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