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alacant

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Everything posted by alacant

  1. alacant
    Nothing as sophisticated I'm afraid. This is just brute force and ignorance 60x20 aluminium from the shed/door/window guy.
  2. alacant
    Here's mine. AFAIK -in Europe at least- a collimation cap is an old film canister with a hole in the centre. Maybe that's not it? Some confusing terms! This snap is with the secondary positioned ready for the primary to be tweaked with a star test. Post a picture of yours and we'll be able to help better. HTH
  3. alacant
    Restoration project: sw 254 f4.7 dated 1999. Just look at it and it went out of alignment. Awful focuser (but not as awful as the dual speed Crayford!), awful tube, seized spider, tiny secondary, non springy springs, flexy dovetail... Loadsa frustration but all now tweaked and/or replaced Major breakthrough with the collimation was the rigid box section along the top of the rings. It now holds at all angles. It's even lost that Skywatcher tinniness when you tap the tube. Reasonably sized galaxies at last:)
  4. alacant
    Hi. I don't think it matters how thick they are as the sensor is much closer to the camera connection than the 44mm of any dslr. Any OAG should fit in the 55mm distacnce you need for your coma corrector; get one with a large prisim e.g. this one has 16mm glass. The qhy needs only 18mm so you've loads to play with. OTOH with a dslr, you really have only one choice to get the correct distance simply. HTH.
  5. alacant
    Hi. Be careful. I tried one but sent it back due to the (ridiculous) back focus. My dslr needed to be 18cm from the tube; impossible to hold rigidly and needing a long extension, even with the focuser racked out fully. I think that's the sensible option as you can specify primary to secondary distances and specify a reasonably sized secondary. Here's a snap showing where the focal plane is located...
  6. alacant
    +1. There's a lot of misinformation on OAG focussing. I think this stems from years ago when they may well have been problematic. But modern cameras and focusers make them easy to manage; well worth the (not much extra and probably maybe even a bit less) extra cost for those pinpoint stars. Every time:) Cheers.
  7. alacant
    Hi. Maybe you could re-aluminise it? Cheers.
  8. alacant
    Ah, really? AFAICT it's the only sw Newtonian that doesn't lose light by missing the secondary. Admittedly, our test is crude. Hold paper at the open end of the tube with the telescope pointed at the sun. On the 130, nada. On all other sws we've tried, you get a nice focused point of light, enough to burn the paper where the light from the primary is not intercepted by the secondary. There are some details here. Oh, and tremendous globular. Not much wrong with the secondary there!
  9. alacant
    There's only one way out; we'll have to go back to taking photos of stars rather than talking about taking photos of stars. Much easier!
  10. alacant
    So, just to be certain. I take m82 with my dslr on a skywatcher. I'm gonna need longer with the same camera attached to the La Palma 2m telescope?
  11. alacant
    Ahhgghh! So I haven't understood. What if I pointed them at m82?
  12. alacant
    He's unlikely to ever look here so we're quite safe! There was one thread where it seemed to make sense though; the 2 metre reflector at La Palma. That's f10. So it must need a longer exposure than a f7 skywatcher refractor? Then I got it! HTH. Just to support @filroden above, AFAICT you have not changed the aperture of the telescope so the exposure time is the same with or without the reducer. --- --- --- But hey, who cares? Let's just get out there and take photos! Cheers and clear skies.
  13. alacant
    Hi everyone. It was nice getting back to the sw130 having been working with a sw250p for the up and coming galaxies. It also shows how stable it is; wind -even gentle gusts- are enough to ruin frames in the 250 whereas the 130 is barely affected. Clusters in the wind: m44 ngc2281 m46-m47 Thanks for looking and clear skies.
  14. alacant
    Yes. There are 2 off 2.5" extension tubes and 2.5" to 2" + 2" to 1.25" adaptors and a rather boring 26mm eyepiece. HTH.
  15. alacant
    With the primary springs fully compressed, a dslr focuses with the draw tube 20mm from fully retracted; no intrusion of the focuser draw tube into the light path. HTH.
  16. alacant
    I think they have several. When we've ordered from them, we've always received a new telescope. No signs of use or even re-packaging. A side by side setup to cut down on imaging time perhaps;)
  17. alacant
    Inspired by recent activity here, I pointed toward the dreaded Alnitak. I thought a CLS may tame it a little. How silly of me... 700d, around 90 minutes
  18. alacant
    Hi everyone. My annual visit to M42. I tried a CLS to see what if I could get any of that greenish-turquoise you see occasionally. A little perhaps. Cheers and Clear skies.
  19. alacant
    Hi. It's the same but with the added advantage that its shape fits a standard 1.25" focuser so focusing is far easier. With the asi, because of its shape, you can't push-pull in a tube to focus. I think the zwo guys are addressing this issue now by producing 1.25" cameras for guiding. Everywhere I've pointed so far -including meridian flips- there have been several stars available. HTH.
  20. alacant
    Hi everyone It's good to have the reliable-no-nonsense 130 ready for wide stuff. Here's my CLS take on la roseta. I transferred the camera with oag intact after a session with another telescope, but with the intention of using the guidescope anyway. No need. Despite changing coma correctors, focus was perfect. Amazing! Comments -especially on the colour scheme- most welcome. Thanks for looking and clear skies. 700d, 2 hours
  21. alacant

    It should say 'Latest un-classifieds', surely.

    1. JohnSadlerAstro

      JohnSadlerAstro

      You've got a point tbh

  22. alacant
    ** No it's not. With PHD2, you have to make a new dark library. Only takes a few minutes though:) HTH.
  23. alacant
    Sorry. My poor explanation. You attach a dslr with a GPU (Aplanatic) coma corrector; the latter not affecting the position of focus. To focus, you find you need to rack out the focuser (away from the tube). You get to the furthest point away from the tube; the focuser will not rack out any more. You are still not in focus, needing several more cm outward. Moving the primary up the tube would make matters worse:( Due to its design, I cannot use an extension tube with the cc but even if I could, I'd still end up with a dslr 15cm from the tube; flex city! Cheers and thanks for your replies.
  24. alacant
    Hi. Unfortunately, that would make matters worse. I'm already at the end of outward travel of the focuser; I need further out. I've reluctantly given up. Here's my newt:
  25. alacant
    Thanks. Good to know. Next problem is that it doesn't reach focus with a dslr. Even with an 11mm Canon t-ring, there's not enough outward travel on the focuser. As I'm using the Aplanatic cc I can't use an extension tube so I'm gonna need a collar which slides over the cc to push the camera further out from the focuser, or take pot luck tightening the focuser without pushing the cc fully home. Why they've put the secondary so close to the primary, I've no idea. Close to giving up. Surely, it can't be this difficult! Any ideas anyone? Cheers and clear skies.
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